GAS OPERATIONS CONSTRUCTION STANDARDS INDEX - MAINS

Transcription

1 9NSTAR GAS GAS OPERATIONS CONSTRUCTION INDEX - MAINS Date Issued: 04-DEC-2012 Page 1 ofl Document Number Document Title Current Revision Revision Date C C C C-1l2 C-1l4 C-1l8 C-1l9 C C Mains Selection and Installation of Road Boxes Plastic Main Installation (60 PSIG or less) Plastic Main Insert Installation (60 PSIG or less) Connections: Welded Steel Branches - Main Not in Service Connections: Welded Steel Branches - Main in Service Connections: Plastic Branches From Metallic Mains Connections: Cast or Ductile Iron Mains - Main in Service Pipeline Direction Changes o o o o o o o o o C C C C I C C C C C Coupling Installation: General Instructions Bolted Couplings Coupling Installation: Tie Rods for Steel Mains Crossings: Highway Crossings: Railroads Steel Pipe End Closure - Blankplate Welded Steel Drips Plastic Drips Excavation and Backfilling Permanent Paving and Surface Restoration o o o o 1 o o o o 04-DEC /2010 C C C I C Handling and Installation of Coated and Wrapped Steel Pipe Handling and Installation of Plastic Pipe Cleaning Steel Gas Mains by Pigging Testing of Gas Mains o o o 1 04-DEC-2012,,

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3 MAINS C-100-1/2 MAINS 1. The purpose of these Standards is to provide uniform practices and minimum requirements for the installation of gas mains. These Standards are designed to comply with the requirements for the transportation of gas as set forth in the rulings of the Department of Transportation, Title 49, Part 192, and the rules of the Massachusetts Department of Telecommunications and Energy 220 CMR 100, and revisions thereto. 2. A main, when referred to in these standards, means a distribution line that serves as a common source of supply for more than one service. 3. For the purpose of these Standards there are three Pressure Classifications for Mains as follows: a. Low-Pressure Mains: Those, which operate at a pressure of 2 PSIG or less. b. Intermediate-Pressure Mains: Those which operate at a pressure above 2 PSIG but not greater than 60 PSIG. c. High-Pressure Mains. Those which operate at a pressure above 60 PSIG but not greater than 200 PSIG MAOP unless higher pressure operation is specifically approved by the Department of Telecommunications and Energy. 4. It is the intent of these Standards that connections and extensions to mains shall be made without the escape of gas, except when not possible on low pressure only. Deviations from this practice shall require the prior approval of the Director of Distribution and Chairman of the Standards Committee. 5. Before any section of metallic main is cut for any reason, jumper cables shall be installed before starting the operation and shall remain connected until the job is completed. Jumper cables of at least 1/0 stranded welding cable shall be used. 6. Pipelines certified with a maximum allowable operating pressure in excess of 200 PSIG MAOP are considered to be a special case and are not covered by these standards. All installation and design modifications on this class line must comply with the Massachusetts Department of Telecommunications and Energy 220 CMR 109 and must be reviewed by the Engineering Department. 7. All segments of steel pipe and fittings shall be cathodically protected in accordance with the requirements of the NSTAR Gas C-500 Corrosion Control Standards.

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5 MAINS C-106-1/2 SELECTION AND INSTALLATION OF ROAD BOXES 1. This standard applies to the selection and installation of boxes, which protect and give access to cocks, gates, drip risers, and test stations installed underground in roadways, streets or anywhere subjected to heavy traffic. See M - 27 Road Boxes. 2. All boxes shall be selected such that the inside box diameter is sufficient to provide access and working space as required. 3. Install boxes such that surface loads cannot be transmitted to the pipeline. 4. The top of the box shall be set to conform with the finish grade in the immediate area. 5. Test wires or tracer wire should not be installed in roadway valve boxes where wires may hinder valve operation. Where appropriate, test station or tracer wires may however, be brought up the outside of the box shaft extension and enter the box just below the cast iron head. Multiple wire test stations should be installed in a separate box.

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7 MAINS C-110-1/16 PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) FIGURE 1: TYPICAL PLASTIC MAIN INSTALLATION LOW AND INTERMEDIATE PRESSURES DO NOT PURGE IN HOLE - EXTEND RISER ABOVE GRADE CONDUCT PRESSURE TEST FROM ABOVE GRADE 1 Purge Fitting (Main Punch Tee) (M-145) 9 Protective Sleeve (M-145) 2 Test/Fill/Vent Riser (See C-186, C-183, 10 Warning Tape (M-269) (See note e.) C-184) Extend To Above Grade 11 Existing Plastic Main 3 Fusion Joint (Socket, Butt, or Electrofusion, M-140, 145) 12 New Main Relay or Extension 4 Plastic Pipe (M-252) 13 Transition Fitting (M-135) 5 Plastic Pipe Cape (M-145) Weld Elbow (M-137) 6 Tracer Wire (See note e.) 15 Lock Wing Cock (M-53) 7 Pressure Test Assembly - Fittings as required. 16 Threaded Plug 8 Pressure Gauge NOTE: SEE PAGE 2 FOR NOTES

8 C-110-2/16 MAINS PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) INSTALLATION INSTRUCTIONS A. The installation of plastic fittings, pipe, etc., and the use of plastic specialty tools shall be done by properly trained and certified personnel in accordance with qualified and approved procedures. B. All plastic materials (pipe, fittings and valves) to be heat fused shall preferably be of the same material and preferably from the same resin manufacturer. Dissimilar materials may be joined by mechanical methods or by qualified and approved heat fusion procedure. C. Excavation and backfilling shall be in accordance with C-150. D. All steel components shall be cathodically protected in accordance with C-500. E. All plastic mains shall be laid with a tracer wire. Tracer wire to be #10 or #12 A.W.G. solid copper wire with T.H.W.N. and/or T.H.W. insulation to be located directly below the main in close proximity but not in direct contact. Yellow plastic warning tape stating in black letters CAUTION - BURIED GAS LINE BELOW to be installed above installed above pipe approximately one (1) foot below finished grade. F. Handle and install plastic pipe in accordance with C-173. G. Install and pressure test purge fitting (inlet service connection). Tap purge connection. H. Install pressure test fitting and pressure test main in accordance with C-186. I. All live gas work to purge the new main into service and tie into an existing main shall be done by properly trained and certified personnel and in accordance with the applicable NSTAR Gas Operating and Maintenance Procedures. J. Warning tape is not required for mains installed by trenchless methods. Tracer wire is to be installed along with main.

9 MAINS C-110-3/16 PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) FIGURE 2: TIE INS TO EXISTING MAINS LOW PRESSURE - PLASTIC TO PLASTIC CATHOFICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 Plastic Pipe (M-252) 7 Transition Fitting (M-135) 2 Butt Fusion (Typical 4" Ø through 8" Ø) 8 Positive Sleeve (M-145) 3 Socket Fusion Coupling (M-145) 9 Compression Coupling (Unrestrained M-121) (Typical through 3" Ø) 10 Lug and Harness Assembly (M-126) 4 Electrofusion Coupling (M-140) 11 Butt Weld (See C-400 Welding) 5 Stiffener Assembly 12 Bond/Anode Connection 6 Positive Restraint Bolted/Mechanical Coupling (M-121/122)

10 C-110-4/16 MAINS PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) FIGURE 3: TIE INS TO EXISTING MAINS LOW PRESSURE - CAST IRON TO PLASTIC 1 Existing Cast Iron Main CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 2 Positive Restraint Cast Iron To Steel Bolted/Mechanical Coupling (M-121/122) 3 Stiffener Assembly 4 Plastic Pipe Segment Or Extension (M-252) 5 Bond/Anode Connection

11 MAINS C-110-5/16 PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) FIGURE 4: TIE INS TO EXISTING MAINS LOW PRESSURE - STEEL TO PLASTIC CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 Plastic Pipe Segment Or Extension (M-252) 2 Existing Steel Pipe 3 Butt Weld (See C-400 Welding) 4 Transition Fitting (M-135) 5 Stiffener Assembly 6 Protective Sleeve (M-145) 7 Positive Restraint Bolted/Mechanical Coupling (M-121/122) 8 Compression Coupling (Unrestrained M-121) 9 Lug and Rod Harness Assembly (M-126) 10 Butt Fusion (Shown), Socket Fusion, or Electrofusion Couplings (M-140,145) 11 Bond/Anode Connection

12 C-110-6/16 MAINS PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) FIGURE 5: TIE INS TO EXISTING MAINS LOW PRESSURE - STEEL TO PLASTIC (Continued) (See Page 9 for Fittings Description) CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL

13 MAINS C-110-7/16 PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) FIGURE 5: TIE INS TO EXISTING MAINS LOW PRESSURE - STEEL TO PLASTIC (Continued) Component Description (Refer to page 8 - opposite page) 1 Plastic Pipe (M-252) 2 Existing Steel Main 3 Butt Weld (See C-400 Welding) 4 Transition Fitting (M-135) 5 90 Weld Elbow (M-137) 6 Protective Sleeve (M-145) 7 Positive Restraint Bolted/Mechanical Coupling (M-121/122) 8 Coupling End Cap Insert 9 3 Way Top Bore Stop and Tap Fitting (M-141) 10 Butt Fusion (Shown), Socket Fusion, or Electrofusion Couplings (M-140,145) 11 3 Way Spherical Stop and Tap Fitting (M-141) 12 Bond/Anode Connection

14 C-110-8/16 MAINS PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) FIGURE 6: TIE INS TO EXISTING MAINS INTERMEDIATE PRESSURE - PLASTIC TO PLASTIC CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 Plastic Pipe (M-252) 7 Transition Fitting (M-135) 2 Butt Fusion (Typical 4" Ø through 8" Ø) 8 Positive Sleeve (M-145) 3 Socket Fusion Coupling (M-145) 9 Uninsulated Compression Coupling (Typical through 3" Ø) (Unrestrained M-121) 4 Electrofusion Coupling (M-140) 10 Uninsulated Lug and Harness Assembly (M-126) 5 Bond/Anode Connection 6 Positive Restraint Bolted/Mechanical 11 Butt Weld (See C-400 Welding) Coupling (M-121/122)

15 MAINS C-110-9/16 PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) FIGURE 7: TIE INS TO EXISTING MAINS INTERMEDIATE PRESSURE - CAST IRON TO PLASTIC 1 Existing Cast Iron Pipe CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 2 Positive Restraint Bolted/Mechanical Coupling (M-121/122) 3 Bond/Anode Connection 4 Transition Fitting (M-135) 5 Positive Sleeve (M-145)

16 C /16 MAINS PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) FIGURE 8: TIE INS TO EXISTING MAINS INTERMEDIATE PRESSURE - STEEL TO PLASTIC CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 Plastic Pipe Segment Or Extension (M-252) 7 Positive Restraint Bolted/Mechanical Coupling (M-121/122) 2 Existing Steel Pipe 8 Compression Coupling (Unrestrained M-121) 3 Butt Weld (See C-400 Welding) 9 Lug and Harness Assembly (M-126) 4 Transition Fitting (M-135) 10 Butt Fusion (Shown), Socket (M-145, or 5 Bond/Anode Connection Electrofusion (M-140) Coupling 6 Protective Sleeve (M-145) PAGE 13 FITTINGS IN ADDITION TO ABOVE 11 3 Way Top Bore Stop and Tap Fitting (M-141) 12 3 Way Spherical Stop and Tap Fitting (M-141) 13 Coupling End Cap Insert Weld Elbow (M-137)

17 MAINS C /16 PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) FIGURE 9: TIE INS TO EXISTING MAINS INTERMEDIATE PRESSURE - STEEL TO PLASTIC (Continued) (See Page 12 for Fittings Description) CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL

18 C /16 MAINS PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) INSTALLATION INSTRUCTIONS a. The drawings on pages C through 11 show the arrangement of fittings that may be used to construct tie-ins. The method used for a particular main extension will depend on the specific conditions of the extension. Additional methods may be used only with specific approval of the Director of Distribution. b. When making a plastic to plastic tie-in, a butt fusion, socket fusion, or electrofusion is preferred. Regarding Intermediate-Pressure tie-ins, if the use of steel transition fittings is necessary they should be welded. If welding is not possible the transition pieces may be connected using a positive restraint bolted compression coupling or non-positive restraint couplings with tie rods - See C-127. The use of positive restraint bolted/mechanical couplings with stiffener assemblies is permitted on low pressure plastic tieins only. c. For Intermediate-Pressure tie-ins between steel or cast iron plastic mains, a transition fitting and insulated positive restraint bolted mechanical coupling is required. An alternative is the use of a compression coupling with tie rods, either insulated or non-insulated as required. d. A method of positive restraint must be installed to prevent pull-out at the compression coupling or bell joint. Methods of restraint not illustrated must have prior approval by the Director of Distribution. See C-125 for the installation of bolted type compression couplings. e. Exercise care to protect both the transition fit and compression coupling from excess heat in welding the lug and tie rod assemblies. See C-127 for the installation of lug and tie rods assemblies. f. For intermediate pressure tie-ins between steel and plastic mains the use of a line stopper or 3-way tee fitting may be required. g. See C-500, Corrosion Control for cathodic protection and coating requirements on pipe segments and metallic fittings.

19 MAINS C /16 PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) FIGURE 10: TYPICAL PLASTIC VALVE INSTALLATION 1 Plastic Valve (M-355) 2 Butt Fusion, Socket (M-145 Shown), Electrofusion (M-140 Shown) Coupling or Positive Restraint Mechanical Coupling (M-121, 122) (permitted on low pressure plastic to plastic joints) 3 Road Box (M-27) 4 Tracer Wire (See C Note e.) 5 Warning Tape (M-269) (See C Note e.) NOTES a. See C for installation instructions. b. The coupling or joints method used, is dependent upon the specific requirements of the particular installation. The use of mechanical positive restraint couplings is permitted on low pressure plastic to plastic joints only. For intermediate pressure system mainline joints the use of a fusion type joint is recommended. Typically, up to 3" diameter may be socket or butt fused. 4" thru 8" diameter are usually butt fused or use electrofusion couplings. 2" and smaller may be socket fused or joined with approval mechanical couplings (M-122).

20 C /16 MAINS PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) FIGURE 11: STEEL VALVE INSTALLATION IN PLASTIC MAINLINE RUN CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 Plastic to Steel Transition Fitting (M-135) 7 Butt Fusion (Shown), Socket (M-145), 2 Protective Sleeve (M-145) Electrofusion (M-140) Coupling or on Low Pressure Systems-Bolted/Mechanical Couplings with Stiffener Assemblies 3 Plastic Pipe (M-252) (M-121/122) 4 Steel Pipe for Torsional Stability (M-251) 8 Road Box (M-27) 5 Steel Valve (M-351, M-353) 9 Tracer Wire 6 Warning Tape (M-269) 10 Butt Weld (See C-400 Welding) NOTES a. Alternate methods and systems to provide torsional stability other than the method shown must have specific prior approval by the Engineering Department.

21 MAINS C /16 PLASTIC MAIN INSTALLATION (60 PSIG OR LESS) FIGURE 12: END OF MAIN AND PURGE CONNECTION 1 Plastic Pipe Cap (M-145) 12 Steel Pipe Purge Vent Riser 2 Butt Fusion (Shown), Socket (M-145) or 13 Pressure Test Assembly - Fittings as required. Electrofusion Coupling (M-140) 14 Pressure Gauge 3 Plastic Pipe (M-252) 15 Threaded Plug 4 Inlet Service Connection (M-145) 5 Plastic Pipe (M-252) NOTES 6 Plastic Pipe Cap (M-145) a. Length of squeeze-off nipple shall be as short as possible to accommodate the final stop-off 7 Butt Fusion (Shown), Socket (M-145) or and cap installation. Cut the protective sleeve Electrofusion Coupling (M-140) accordingly. 8 Transition Fitting (M-135) b. Install and cap after purge is complete. All live gas work to purge the new main into service 9 90 Weld Elbow (M-137) and tie an existing main shall be done by properly trained and certified personnel and in 10 Steel Fill Pipe Riser (M-251) accordance with the applicable NSTAR Gas Operating and Maintenance Procedures. 11 Lock-Wing Cock (M-53)

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23 MAINS C-112-1/2 PLASTIC MAIN INSERT INSTALLATION (60 PSIG OR LESS) FIGURE 1: MAIN REPLACEMENT - PLASTIC PIPE INSERT (60 PSIG OR LESS) CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 Plastic Pipe (Main Insert) (M-252) 8 Stiffener Assembly - LOW PRESSURE MAINS ONLY 2 Existing Cast Iron Main 9 Plastic Pipe (M-252) 3 Plastic End Protector Bushing (M-118 up to 2" or other methods to prevent chafing on larger sizes) 10 Transition Fitting (M-135) - REQUIRED ON INTERMEDIATE PRESSURE MAIN 4 Existing Steel Main TIE INS 5 Positive Restraint Bolted / Mechanical 11 Protective Sleeve (M-135) Coupling Steel To Steel (M-121/122) 12 Butt Fusion(Shown), Socket (M-145) or 6 Positive Restraint Bolted / Mechanical Electrofusion (M-140) Coupling Coupling Cast Iron To Steel (M-121/122) 13 Plastic Reducer Coupling (M-145) 7 Bond / Anode Connection 14 Butt Fusion, Socket (M-145-Shown) or Electrofusion (M-140) Coupling

24 C-112-2/2 MAINS PLASTIC MAIN INSERT INSTALLATION (60 PSIG OR LESS) 1. INSTALLATION INSTRUCTIONS: a. Isolate section to be inserted. b. Pig, clean, ream and blow out section as necessary. c. Insert carrier pipe using a bull-nose protector on the forward end. d. See C-500 for Cathodic Protection. e. See C-186 for Pressure Test. f. See C-720 for Safety Procedures g. Use a bond wire to bridge any gap in the abandoned main. See C-592 for thermit weld. CAUTION: Thermit welds to casing pipe must be made prior to inserting plastic carrier. h. Refer to C-150 for Excavation and Backfilling. i. See C-173 for general instructions regarding the Handling and Installation of Plastic Pipe.

25 MAINS C-114-1/2 CONNECTIONS: WELDED STEEL BRANCH CONNECTIONS MAIN NOT IN SERVICE FIGURE 1: STEEL PIPE BRANCH CONNECTION - PREFERRED FIGURE 2: STEEL PIPE BRANCH CONNECTION - REINFORCED NOZZLE DESIGN FIGURE 3: STEEL PIPE BRANCH - NOZZLE CONNECTION See Note a. CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 Reinforced Saddle (M-137) NOTES a. See C-416 for required reinforcement. 2 Weld-O-Let Type Fitting (M-137) b. For Pipe Standards see M-251. c. For Welding Standards See C Straight or Reducing Tee (M-127) d. See C-518 for Field Coating

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27 MAINS C-118-1/2 CONNECTIONS: WELDED STEEL BRANCH CONNECTIONS MAIN IN SERVICE FIGURE 1: WELDED STEEL BRANCH CONNECTIONS MAIN IN SERVICE CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 3-Way Tee (M-141) See Note c. NOTES a. Follow manufacturer's instructions when using 2 Spherical 3-Way Tee (M-141) 3-Way fittings for making Branch Connections. 3 Existing Steel Main b. For Welding Standards see C Welded Branch Connection -ie., Weld End Insulator (M-125), Transition Fitting (M-135), c. Nozzle connection (See C-114) may be used or Steel Pipe (M-251 in place of welding fitting (M-137). See C-416 for required reinforcement. d. Insulate as close to branch connection as possible when required. e. See C-518 for field coating.

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29 MAINS C-119-1/2 CONNECTIONS: PLASTIC BRANCHES FROM METALLIC MAINS FIGURE 1: LOW PRESSURE PLASTIC BRANCH CONNECTIONS EXISTING STEEL AND CAST IRON MAINS CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 Existing Main 8 Transition Fitting (M-135) or Steel Pipe (M-251) 2 Positive Restraint Bolted / Mechanical Coupling (M-121/122) With Stiffener 9 Protective Sleeve M-145) Assembly IPS To IPS 10 Non - Positive Restraint Mechanical/ Bolted 3 Plastic Pipe (M-252) Branch Coupling (M-121) 4 Plastic Tee (M-145) 11 Steel Tee (M-137) 5 Anode Connection 12 Lug and Rod Harness Assembly (M-126) 6 Butt Fusion (shown), Socket (M-145) or 13 Butt Weld - See C-400 Welding Electrofusion (M-140) Coupling or Item 2 (above). 14 Steel Pipe (M-251) 7 Positive Restraint Bolted / Mechanical 15 Steel Reducer (M-137)- Optional As Required Coupling (M-121/122) With Stiffener Assembly C.I. To IPS

30 C-119-2/2 MAINS CONNECTIONS: PLASTIC BRANCHES FROM METALLIC MAINS FIGURE 2: INTERMEDIATE PRESSURE PLASTIC BRANCH CONNECTIONS EXISTING STEEL AND CAST IRON MAINS CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 Existing Main 6 Butt Fusion (shown), Socket (M-145) or Electrofusion (M-140) Coupling or Item 2 Positive Restraint Bolted / Mechanical 2 (above). Coupling (M-121/122) With Stiffener Assembly IPS To IPS 7 Positive Restraint Bolted / Mechanical Coupling (M-121/122) With Stiffener 3 Plastic Pipe (M-252) Branch Assembly C.I. To IPS 4 Plastic Tee (M-145) 8 Transition Fitting (M-135) or Steel Pipe (M-251) 5 Anode Connection 9 Protective Sleeve (M-145)

31 MAINS C-120-1/4 CONNECTIONS: CAST OR DUCTILE IRON MAINS MAIN IN SERVICE FIGURE 1: TYPICAL BRANCH CONNECTION TO EXISTING CAST OR DUCTILE IRON MAINS GREATER THAN 8" DIAMETER CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 Existing Main NOTES a. All live gas work to bag and stop off low- 2 Un-restrained Insulated Compression pressure cast iron mains shall be done by Coupling (M-121) properly trained and certified personnel and in accordance with the applicable NSTAR Gas 3 Steel Pipe (M-251) Operating and Maintenance Procedures. b. For Welding Standards see C Steel Tee (M-137) c. See (C-125) for installation of compression couplings. 5 Butt Weld (See C-400 Welding) d. See C-518 for Field Coating. 6 Weld Reducer 7 Steel Pipe or Transition Fitting

32 C-120-2/4 MAINS CONNECTIONS: CAST OR DUCTILE IRON MAINS MAIN IN SERVICE FIGURE 2: TYPICAL SPLIT SLEEVE HOT TAP CONNECTION CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 Tapping Sleeve (M-142) NOTES a. Follow manufacturer's instructions for 2 Top Bore Stop Fitting (M-141) installing tapping sleeve. b. Tapping valve (M-142) or Stop Fitting 3 Flange (M-148) (M-141) may be used. c. Install flange (M-148). d. Remove flange and continue branch installation after the main is tapped. All live gas work to tap the main shall be done by properly trained and certified personnel and in accordance with the applicable NSTAR Gas Operating and Maintenance Procedures.

33 MAINS C-120-3/4 CONNECTIONS: CAST OR DUCTILE IRON MAINS MAIN IN SERVICE FIGURE 3: TYPICAL SWING JOINT BRANCH CONNECTION CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 Style 90 Ell (M-133, M-138) NOTES a. Taps in cast iron pipe are permitted without 2 X-Heavy Threaded Nipples (M-251) reinforcement to a size not more than 25% of the nominal diameter of the pipe except that a 3 Mechanical Sleeve (M-142, M-143) 1¼ tap may be made without reinforcement in a 4" cast iron or ductile iron pipe. b. See C-518 for Coating Standards.

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35 MAINS C-122-1/2 PIPELINE DIRECTION CHANGES 1. WELDING FITTING: a. Use welding fittings as manufactured whenever possible. b. Modified welding fitting: 1) Transverse segments of welding elbows may be used for direction changes. 2) For 2" larger pipe the arc length as measured along the crotch of the fitting must be at least one inch. MINIMUM ALLOWABLE ANGLES Long Radius Elbows Short Radius Elbows 2" 31 2" 70 3" 21 3" 46 4" 15 4" 33 5" 13 5" 26 6" 10 6" 21 8" 7 8" 16 10" 6 10" 11 12" 5 12" 10 FIGURE 1: SEGMENTED WELD ELBOW (2" LONG RADIUS 90º SHOWN) Example for 2" Long Radius Weld Elbow

36 C-122-2/2 MAINS PIPELINE DIRECTION CHANGES 2. BENDING: a. All bending shall be done with a machine or shoe and produce a smooth contour, free of mechanical damage. Heat shall not be applied to the pipe during the bending operation. b. The longitudinal seam shall be on neutral axis of the bend, i.e., not on the inside or outside of the bend unless the bend is made with an internal bending mandrel or the pipe is 12" or less in outside diameter or has a diameter to wall thickness ratio less than 70. c. For pipe 4" or larger, the difference between the maximum and minimum diameter at bend shall not exceed 2-1/2% of the nominal diameter. d. Pipe 12" or larger shall not be deflected more than 1-1/2 in any length equal to the diameter. e. Each circumferential weld subjected to stress during bending must be nondestructively tested (see C- 420). FIGURE 2: MITER JOINTS 3. MITER JOINTS: a. Miter joints may be used for direction changes when it is impractical to use welding fittings or bends. b. The pipe may not be deflected more than 12-1/2 per miter joint. Miter joints must be separated by at least one pipe diameter as measured from the crotch of each joint.

37 MAINS C-125-1/2 COUPLING INSTALLATION: GENERAL INSTRUCTIONS BOLTED COUPLINGS 1. GENERAL INSTRUCTIONS a. This standard applies to the installation of bolted compression couplings used to connect lengths of metallic pipe as well as to fittings or valves, which may be equipped for this connection. Wherever appropriate, a positive restraint type compression coupling should be used. b. Couplings used shall conform to M-121, M-122, M-123. c. Couplings shall preferably be installed with 1" space between the pipe or fitting ends. If the space exceeds 2", a "long middle ring" shall be used. d. Pipelines expand and contract due to temperature changes. Consideration shall be given to the ambient temperature at the time of installation so that the pipe ends will not touch during maximum expansion and the space between pipe ends at maximum contraction shall not exceed the allowable amount for the particular coupling being used. Maximum axial movement shall not exceed 3/8" in any one coupling. Tie rods, when required, shall be adjusted accordingly (See C-127). e. When couplings are to be used to join cast iron to steel pipe, measure the cast iron with calipers, measuring tape or PI tape before selecting proper size coupling.* Do not attempt to make an undersize coupling fit by removing the insulator. f. The manufacturer's instructions for the installation of all couplings shall be adhered to at all times, particularly with regard to the tightening of the nuts to their proper torque. g. Refer to C-518 for field coating compression couplings. h. Refer to C-518 for insulating compression couplings. i. Warning - Do not weld on "Al-Clad" coated couplings. Toxic fumes may be formed. j. Use of positive restraint couplings as end caps is allowed on steel and cast iron mains operating at or below 60 psig. Use of non-positive restraint coupling as end cap is prohibited unless specifically approved by the area manager. Except on mains that operate at 1 psig or less, non-positive restraint couplings used as end caps shall be secured to the main. Methods to secure non-positive restraint end caps to the main must be approved by the area manager. Pressure testing against a non-positive restraint end cap is strictly prohibited without prior approval from the area manager. *To calculate correct size coupling *Diameter = Circumference

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39 MAINS C-127-1/4 COUPLING INSTALLATION: THE-RODS FOR STEEL MAINS 1. APPLICATION Mechanical / bolted compression coupling assemblies and installations are required to resist the pipe ends from being pulled out of the coupling by forces imposed by line pressure, pipeline direction changes, thermal expansion and contraction or external forces. 2. DESIGN Non-Positive restraint couplings must be restrained by the use of tie rod and lug assemblies. Standard assemblies (M-126) shall be used whenever possible. If not possible, see C-127-3/3 for fabricated assemblies. Maximum axial movement of pipe ends must not exceed 3/8 inch in any non-positive restraint type coupling. Positive restraint type couplings are to be used to prevent pullout due to internal pressure only. Couplings are not to be used above 100 psig unless encapsulated with a welded fitting specifically designed for coupling encapsulation. Use of positive restraint couplings as end caps is allowed on steel and cast iron mains operating at or below 60 psig. Use of non-positive restraint coupling as end cap is prohibited unless specifically approved by the area manager. Except on mains that operate at 1 psig or less, non-positive restraint couplings used as end caps shall be secured to the main. Methods to secure non-positive restraint end caps to the main must be approved by the area manager. Pressure testing against a non-positive restraint end cap is strictly prohibited without prior approval from the area manager. FIGURE 1: TIE ROD AND LUG HARNESS ASSEMBLY 1 Lug (M-126) 2 Plastic Bushing 3 Metal Washer 4 Nuts (Doubled) 5 Threaded Rod

40 C-127-2/4 MAINS COUPLING INSTALLATION: THE-RODS FOR STEEL MAINS 3. INSTALLATION Determine lug location and stud length from the manufacturers installation instructions or from the following table: Coupling Middle Stud Length Dimension From Pipe Ring Length (Inches) End of First Point (Inches) of Lug (Inches) / ½ ½ ½ Use the following table to select the required number of rod and lug assemblies: LUG AND ROD REQUIREMENTS Low Pressure thru 20 psig Over 20 psig to 100 psig Pipe Size 5/8" 3/4" 7/8" 5/8" 3/4" 7/8" (Nominal) Rod Rod Rod Rod Rod Rod INSTALLATION INSTRUCTIONS 1. Prepare pipe surface. Remove deflection ring assemblies from lug if so equipped. Weld lug to pipe using 1/4 fillet for.250 or.219 thick lugs or 3/8 fillet for.375 thick lugs. Lugs must be welded at all inside and outside edges and must be equally spaced around pipe. 2. Assemble studs, lug adaptors, deflection rings or washers, and nuts. Tighten nuts snugly unless specifically designed and installed to allow axial movement. Double nut all rods. 3. Standard lug and rod assemblies are available as either insulated or non-insulated. Insulated lugs may be converted to conducting lugs by removing the insulated deflection ring assembly, or insulating bushing and replacing it with a lug adaptor or washer. 4. When installing the tie-rods, consideration should be given to the ambient temperature (See C-125). Manufactured assemblies are not furnished with nuts. When requisitioning stock and fittings, obtain a sufficient quantity of nuts to double nut each rod installed to maintain the correct adjustment.

41 MAINS C-127-3/4 COUPLING INSTALLATION: THE-RODS FOR STEEL MAINS 4. FABRICATED ASSEMBLIES When necessary to fabricate assemblies, the following lug detail shall be used: FIGURE 2: TYPICAL FABRICATED LUG DESIGN NOTES 1. For 2" diameter pipe size use a manufactured assembly only. 2. Insulating assemblies shall be used when the rods are installed over insulating couplings. Insulators must be on the same side of the insulating coupling as the plastic sleeve and skirted insulating gasket. If a fabricated assembly is to be electrically insulated, use a one piece sleeve and washer (M-169). 3. Install cathodic protection and field coat entire assembly in accordance with C-500.

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43 MAINS CROSSINGS: HIGHWAY C-132 Page 1 of 4 Pipe crossing under highway road beds and across rights of way shall be made in accordance with the requirements of Title 49 CFR Part 192 and the rules of the Massachusetts Department of Public Utilities (DPU), 220 CMR 101 and revisions thereto. Prior arrangements shall be made as to method of construction, casing requirements, depth of casing below used surface of the road and length of casing. Plans shall be prepared showing location of crossing and details of the crossing. The following guides are to be used in preparing the plans and specifications for highway crossings where a casing for the carrier pipe is required. The casing shall be designed to withstand the superimposed loads. a. The pipe shall cross the highway at as close to a right angle as practical. b. Where pipe sections of the casing are to be joined, welding is the preferred method of joining. c. At the ends of the casing, suitable seals shall be installed to prevent the entrance of ground water. d. The casing must have a coating equivalent to the carrier pipe and shall be cathodically protected. e. The carrier pipe shall be electrically isolated from the casing by means of insulating casing spacers. f. Inside the casing, the carrier pipe shall be installed so that it is not in tension. Only butt welded steel pipe joints may be used and double random pipe lengths are recommended so as to minimize the number of welds. Plastic pipe may be used only if there are no joints within the casing. g. If vents are installed on a casing, the vents should be of the breakaway type and must be protected from the weather to prevent water from entering the casing and be screened to prevent the entry of insects. If the casing is not level, the vent shall be attached to the bottom of the casing on the lower end and the top of the casing on the upper end. h. If the ends of an un-vented casing are sealed, and the sealing is strong enough to retain the MAOP of pipe, the casing must be designed to hold this pressure at a stress level of not more than 72% of the Specified Minimum Yield Strength (SMYS). Revised Revised Revised Revised Revised Date By Date By Date By Date By Date By

44 MAINS C-132 CROSSINGS: HIGHWAY Page 2 of 4 FIGURE 1: TYPICAL CROSSING LAYOUT REQUIRING CASINGS Carrier Pipe-Nominal Diameter Casing-Minimum Nominal Diameter CASING REQUIREMENTS Casing Wall Thickness NOTES 1. Steel Carrier Pipe (M-251) or Plastic Carrier Pipe a. See C-560 for insulator spacing requirements. (M-252) b. Casing shall extend at least 5 ft. beyond the edge of the highway paving. 2. Steel Casing Pipe (M-251) c. See C-132-3/4 Figure 2 for detail of vent pipe 3. End Seal Boot/Bushing (M-151) 4. Insulated Spacers (M-153) 5. Drain Vent, see note c. 6. Atmospheric Vent, see note c. 7. Link Seals riser. d. Where casings are impractical or additional protection is required, See C-132-4/4 Figure 3 showing Concrete Slabs spanning the trench to undisturbed soil as an alternative method. Steel plates may be used as an alternative with the approval of the Director of Distribution and the Director of Engineering. Revised Revised Revised Revised Revised Date By Date By Date By Date By Date By

45 MAINS C-132 CROSSINGS: HIGHWAY FIGURE 2: TYPICAL BREAKAWAY VENT RISER DETAIL Page 3 of 4 CATHODICALLY PROTECT ALL STEEL PIPE AND METALLIC FITTINGS USED IN TIE INS SEE C-500 CORROSION CONTROL 1 Steel Casing Pipe (M-251) 6 Nut 2 90 Weld Elbow (M-137) 7 Washer 3 Vent Riser (M-251) 8 "BURIED GAS PIPELINE" Sign 4 Slip-On Flange (M-148) 9 Wire Vent Screen 5 Bolt 10 Weldolet (M-137) Revised Revised Revised Revised Revised Date By Date By Date By Date By Date By

46 MAINS C-132 CROSSINGS: HIGHWAY FIGURE 3: TYPICAL CONCRETE PROTECTIVE SLAB DETAIL Page 4 of 4 NOTES a. Where casings are not practical, or additional protection is required, concrete slabs supported by undisturbed soil may be used. Other methods such as steel plates may be used with the approval of the Director of Distribution and the Manager of Engineering. Revised Revised Revised Revised Revised Date By Date By Date By Date By Date By

47 MAINS C-134-1/2 CROSSINGS: RAILROAD Pipe crossings under railroad tracks and across rights of way shall be made in accordance with the requirements of the railroad having jurisdiction as well as the requirements of the Department of Transportation, Title 49, Part 192, and the rules of the Massachusetts Department of Telecommunications and Energy, D.T.E and the American Petroleum Institute, Code No and revisions thereto. Part 5 - "Pipelines" of the American Railway Engineering Association Manual 1972 outlines the necessary information in preparing submittals for consideration by the Authority or Railroad having jurisdiction. Prior arrangements and agreements shall be made as to method of construction, casing requirements, depth of casing below rails, length of casing, isolating valves and special insurance required. Plans shall be prepared showing location and details of the crossings. The following requirements are based on the Consolidated Rail Corporation (CONRAIL) and may be helpful in preparing preliminary plans and specifications for a railroad crossing. 1. CASING REQUIREMENTS a. The casing shall be designed for earth loads and other pressures including a Cooper's E-80 railroad live load plus 50% for impact. b. The casing shall extend 2 feet beyond the toe of the slope, 3 feet beyond the ditch line, 25 feet each side of centerline of outside tracks (right angle measurement) when sealed, or across the entire right of way, whichever is greater. c. Maintain a cover of 5-6 from the bottom of the rail to the top of the casing (4-6 for secondary or industrial tracks). d. The crossing shall be made at right angles when possible and preferably not less than 45 degrees to the track centerline. e. The minimum yield strength of the casing shall be 35,000 psi. f. The casing must not be in contact with any other underground structures. g. Casing shall be sealed and vented (at least 45 feet, measured at right angles) from the centerline of the nearest tracks. Vents shall be installed with insect screens. See M-151 for seals. h. Vents should be of the breakaway type and shall terminate at least 4 feet above ground with a screened turned down elbow, above high water level and at least 4 feet from any electrical wires. Vents shall be connected to the bottom or side of the casing at the low end and the top of the casing at the high end. The only exception to vent pipes is when the pipeline is in a public highway and the location is such that it would be impossible to place them. i. Cathodic protection is required on all casings. j. All joints in the casing shall be welded. 2. CARRIER PIPE REQUIREMENTS a. The hoop stress of the carrier shall not exceed 60% of the SMYS. b. If carrier pipe requirements are more stringent for the rest of the pipeline, they shall apply to railroad crossing. c. The carrier shall be laid slack across the crossing. d. Requirements for the carrier shall apply for 50 feet beyond the centerline of the outside tracks, 2 feet beyond the toe of the slope, or 25 feet beyond the end of the casing, whichever is greater.

48 C-134-2/2 MAINS CROSSINGS: RAILROAD FIGURE 1: TYPICAL RAILROAD CROSSING LAYOUT CASING REQUIREMENTS Carrier Pipe-Nom. Dia Casing-Min. Nom. Dia Casing Wall Thickness Steel Carrier Pipe (M-251) NOTES a. The carrier shall be electrically isolated from 2 Steel Casing Pipe (M-251) the casing and must be cathodically protected. 3 End Seal Boot/Bushing (M-151) b. See C-560 for insulator spacing requirements. 4 Insulated Spacers (M-153) c. See C-132-3/4 Figure 2 for detail of vent pipe riser. 5 Drain Vent-low End Of Pitched Casing, See note c. 6 Atmospheric Vent-High End Of Pitched Casing, See note c. 7 Link Seals

49 GAS OPERATIONS CONSTRUCTION C-146 MAINS - STEEL PIPE END CLOSURE - BLANKPLATE Revision: 1 Date Issued: 04-DEC-2012 Page 1 of 2 FIGURE 1: TYPICAL END PLATE FABRICATION AND ARRANGEMENT PLATE FABRICATION DETAIL PIPE DIAMETER 1-¼" 1-½" 2" PLATE THICKNESS PLATE DIAMETER 3 " 1-¼" 16 3 " 1-½" " 3 " " 3" ¼" " ⅜" " 6" ⅜" 1-⅛" 8" ⅜" 1-⅛" 10" ½" 1-¼" 3 " 12" ⅝" 1-16 NOTES a. Standard welding caps are to be used whenever possible and must be used above 12" nominal pipe size. Inside flat plate end closures may ONLY be used when it is impractical to use standard welding fittings. b. Blank Plate shall be ASTM A36 steel. c. All welding shall be performed in accordance with Gas Distribution O&M Section , Joining by Welding.

50 GAS OPERATIONS CONSTRUCTION C-146 MAINS - STEEL PIPE END CLOSURE - BLANKPLATE Revision: 1 Date Issued: 04-DEC-2012 Page 2 of 2 d. Procedure for installation: 1. Place a magnet on a steel strap, with a length greater than the pipe O.D. 2. Center the steel strap over the blank plate and insert the plate centered in the pipe end using the magnet to hold the strap and plate in position. If the pipe end is beveled place the magnet between the strap and plate thus recessing the plate in the pipe beyond the bevel. 3. Make tack welds and then remove the strap and magnet to complete the fillet weld.

51 MAINS C-148-1/2 WELDED STEEL DRIPS FIGURE 1: TYPICAL WELDED STEEL DRIP POT FABRICATION TABLE NOTES (Preferred) a. Fabricate drip pot in accordance with table. PLATE Weld Cap Fittings shall be used on main sizes MAIN POT HEIGHT THICKNESS over 12". (Dia.) (Dia.) "A" "B" b. All welds to be in accordance with C-400. c. Drip pot shall be installed such that main 2" 6" 2'-5" 5/16" slopes towards pot from both directions. 4" 8" 2'-7" 3/8" d. Main may be field welded to pot or may have 6" 8" 2'-9" 3/8" 18" long main connections for tie by welding 8" 10" 3'-0" ½" or use of compression couplings. 10" 12" 3'-0" 9/16" e. Steel Drip pot shall be cathodically protected 12" 16" 3"-2" 5/8" in accordance with C-500 Corrosion Control 16" 20" 3'-6" Cap Standards. 18" 24" 3'-8" Cap f. Blank Plate End closures shown in adjacent 20" 24" 3'-10" Cap table to be used up to 12" only. See C " 24" 4'-2" Cap for procedure. g. Drip pots shall be pressure tested as specified Pot Risers to be 1" diameter X.H. Steel from Boiler in C-186. Bushing to Road Box. Dip Pipe to be 1" diameter steel (M-251) std. wt. wedged as shown. Set Dip Pipe ½"- 1" above bottom of pot. 1 Steel Pipe (M-251) 6 Shut-Off Cock (M-51) 2 Road Box (M-27 or M-25) 7 1"x ¾" Reducer Coupling (M-137) 3 ¾" Plug and 1" x ¾" Reducer 8 Coupling (M-133, M-138) 4 1½" x 1" Steel Double Tapped or Boiler Bushing 9 Weld Cap (M-137) 5 1½" X.H. Steel Coupling with recessed threads 10 Steel Pot Riser - 1" Dia. X.H. or "Threadolet" type fitting (M-137) 11 1" Steel Dip Pipe (M-251)

52 C-148-2/2 MAINS WELDED STEEL DRIPS FIGURE 2: TYPICAL ALTERNATE WELDED STEEL DRIP POTS NOTES a. When used on low pressure mains see page 1 for material identification, dimensions, dip pipe and riser detail. b. When used for intermediate pressure mains, a special design shall be prepared. c. Siphon drip should only be used when approved by the Director of Distribution.

53 MAINS C-149-1/2 PLASTIC DRIPS FIGURE 1: TYPICAL PLASTIC DRIP POT NOTES a. Drip pot shall be installed such that main slopes towards pot from both directions. b. Drip pots shall be pressure tested as specified in C-186. c. Plastic drip pot may be fabricated and installed during plastic main installation or may have 18" long main connections for tie-in by electrofusion fittings (M-140), or on low pressure mains, by compression couplings (M-121). d. Length of 1" plastic pipe, item (6), shall be determined in the field such that there is a minimum clearance of 4" between the threaded plug, item (10), and the road box cover, item (11). e. Where possible, locate the road box off of the paved surface of the road. 1 Plastic Pipe (M-252) 7 1" Bent Prefabricated Service Riser (M-204) 2 Plastic Tee (M-145) 8 1" x 3/4" Malleable-Iron Reducer Coupling (M-133) 3 Plastic Elbow (M-145) 9 Shut-off cock (M-51) 4 Plastic Cap (M-145) 10 3/4" Malleable-Iron Threaded Plug (M-133) 5 Service Tee (M-145) 11 Road Box (M-27 or M-25) 6 1" Plastic Pipe (M-252)

54 C-149-2/2 MAINS PLASTIC DRIPS FIGURE 2: TYPICAL ALTERNATE PLASTIC DRIP POT NOTE: SEE PAGE 1 FOR NOTES AND MATERIALS

55 GAS OPERATIONS CONSTRUCTION C-150 MAINS - EXCAVATION AND BACKFILLING Revision: 1 Date Issued: 04-DEC-2012 Page 1 of 4 All excavation, backfilling and safety practices must be done in accordance with the Department of Transportation, Title 49, Part 192, Massachusetts Department of Labor and Industries, Bulletin 12, the U.S. Department of Labor, OSHA, Title 29, Part 1910 and the Massachusetts Department of Public Utilities Standard (DPU) and revisions thereto. 1. TRENCHING The Dig Safe Call Center ( ) must be notified at least 72 hours in advance of excavation, exclusive of Saturdays, Sundays and legal holidays except in an emergency but not more than 30 days in advance of construction or the Dig Safe notice expires. Underground gas lines shall not be installed in a trench which contains, or is to contain other structures or piping. The trench should not horizontally overlap or occupy any of the area previously excavated for other parallel underground structures, regardless of the depth of such structures. When the above rules cannot be met, consult the Director of Distribution. Excavations must be properly safe-guarded at all times until backfilled and left safe for travel. Barricades must be used to alert pedestrians and vehicular traffic. When not attended, trenches 3 feet in depth and deeper must be covered, barricaded with fences at least 6 high, or backfilled. At night, place warning lights or flashing barricades effectively along excavations and around spoil piles, equipment, and materials. Along high speed roads, signs and flashing barricades shall be placed in each direction from the construction as required by local governing agencies. Tunneling should be avoided whenever possible. Excavations must be inspected daily and after each rainstorm or other hazard increasing occurrence. If evidence of cave-ins or slides is apparent, all work in the excavation shall cease until the necessary precautions have been taken. Excavations below the base of footing of any foundation or other retaining wall shall not be permitted unless precautions are taken to safeguard personnel. Spoil removed from the trench shall be neatly piled in such a way that it will not hinder the normal flow of surface water, or divert surface water into the trench. Spoil shall not obstruct the working areas on either side of the trench and must be kept at least 2 feet from the edge of the trench. Spoil should not be placed in cross walks. Spoil should be placed in consideration of pedestrian and vehicular traffic safety. When the location of the trench is near trees or shrubbery, never cut large roots or an excessive number of roots of trees or shrubbery except with permission of the Director of Distribution. Hazardous trees, boulders, or other surface encumbrances must be removed or made safe before the excavation begins. In locations where paving is encountered, the paving to be removed prior to trenching shall be edge cut using pneumatic cutters or by saw cutting.

56 GAS OPERATIONS CONSTRUCTION C-150 MAINS - EXCAVATION AND BACKFILLING Revision: 1 Date Issued: 04-DEC-2012 Page 2 of 4 The maximum width of trench and disturbed paving for mains shall be accordance with the following table or as specified for a particular job: PIPE LINE SIZE TRENCH WIDTH 6 inch and smaller 18 inches 8 inch to 12 inch 24 inches 16 inch 30 inches 18, 20 and 24 inch 36 inches The above table is intended to represent average conditions in good earth and is to be followed except where plans and/or permits specify otherwise. For trenching work included in work to be done by a contractor, permission to increase the width must be obtained from the Director of Distribution. Where a wider area of paving width is disturbed without the approval of the Director of Distribution, the additional cost incurred, including extra backfill, temporary paving, permanent paving, etc., shall be at the Contractor's expense. The trench for the gas main shall be excavated to a depth to provide a minimum cover of 36 inches from the top of the main to the used surface of the road. Where this is impractical, the Director of Distribution will determine the procedure to follow. For mains with 24 inches of cover or less, approval from the Director of Distribution and the DPU is needed. C-132, Figure 3 details concrete slabs for physical protection of shallow facilities. Other methods such as steel plates may be used with the approval of the Director of Distribution. The bottom of the trench shall be excavated and graded so that the pipe shall lie on a continuous firm footing. The trench shall be prepared so that the gas main may be installed with a minimum clearance 12 inches from other gas facilities and/or any other underground structures not used in conjunction with the gas line installation to allow for proper maintenance and to protect against damage. Clearances of less than 12 inches must be authorized by the Director of Distribution. Gas mains shall not be installed within 10 feet of a steam line unless approved by the Gas Engineering Department. Hand excavation shall be used in close proximity to sub-structures of the Company, the City and other utilities. Where so designated, rock shield shall be used for additional protection. If additional excavation is required to maintain clearance or avoid an interference with another utility such as a water main, and the excavation exceeds 4 feet in depth, the requirements of the following paragraph must be met. Shoring of the trench may be found necessary or may be required by City, County, State, or other public or private authorities having jurisdiction over the same and must be installed and removed to their satisfaction. Banks more than 5 feet high shall be shored, laid back to stable slope, or some other means of protection shall be provided where employees may be exposed to moving ground or cave-ins. Trenches less than 5 feet in depth shall be effectively protected when examination of the ground indicates hazardous ground movement may be expected. Sides of trenches 5 feet or more in depth, shall be shored, sheeted, braced sloped or otherwise supported except when the excavation is made entirely in stable rock. Sides of trenches in hard or compact soil, including embankments shall be shored or otherwise supported when the trench is more than 5 feet in depth. When trenches are 4 feet or greater in depth, adequate means of exit, such as a ladder, shall be located so as to require no more than 25 feet of lateral travel.

57 GAS OPERATIONS CONSTRUCTION C-150 MAINS - EXCAVATION AND BACKFILLING Revision: 1 Date Issued: 04-DEC-2012 Page 3 of 4 Shoring shall be adequate to provide for the safety of personnel and the public and shall be done in compliance with all applicable regulations. Solid rock shall be removed to a depth of 4 inches below the standard depth trench, and any trench so excavated shall be padded with earth free from rock or with sand to a minimum depth of 4 inches so that the pipe will be protected from any hard points of rock which might project above the bottom of the trench. If blasting is required, only a qualified and licensed Contractor who has obtained the necessary permits and insurance shall be permitted to do any such Work. Materials removed from the trench that are unsuitable for backfill, shall preferably be hauled away from the job site upon excavation. Usable backfill shall be piled in a manner so as to avoid unnecessary public inconvenience and complaints. 2. SPECIAL EXCAVATIONS: The trench shall be widened and deepened, if necessary, to permit welding and fusing at ends of lengths of pipe. Undermining of the roadway surface to access the welding and fusing work area (Bell type hole) is not permitted. For trenching or excavations at: Highway Crossing refer to C-132 Railroad Crossing refer to C BACKFILLING, COMPACTION AND CLEAN-UP: Backfilling around and over the completed pipe line shall be done with care so as to maintain its grade and alignment and prevent damage to pipe and coating (See OM 4.9.2). Hand labor shall be used to fill and tamp around the pipe until the trench has been backfilled and thoroughly compacted to a 6 inch depth over the pipe. For this portion of the backfilling, approved clean earth or sand shall be used. Sand is not required for mains installed by trenchless methods. Backfilling and Compaction of the rest of the open trench shall meet the requirements of DPU Standard and the requirements of the City, County, or other public or private authority having jurisdiction. The excavated soil shall be evaluated in accordance with section 8.8 of DPU Standard to determine whether or not it is suitable as backfill material. In the event it is evaluated as unsuitable, the excavated material shall be removed from the site and disposed of properly. New material shall be brought in to replace the excavated soil found to be unsuitable. Controlled Density Fill (CDF) shall only be used with the approval of the Director of Distribution or the Area Manager. Compaction of the trench shall achieve soil density values of 95% modified Proctor density. At the request of the NSTAR Gas representative or the City, County, or other public or private authority having jurisdiction, the Contractor shall conduct compaction verification tests to assure that 95% modified Proctor density has been achieved. Backfilling and removal of trench supports shall progress together from the bottom of the trench. Any settlement resulting from the work of a Contractor, which results within six months after completion of the job shall be remedied at the Contractors' expense. The backfilling operation shall include any temporary paving as may be required by the authority

58 GAS OPERATIONS CONSTRUCTION C-150 MAINS - EXCAVATION AND BACKFILLING Revision: 1 Date Issued: 04-DEC-2012 Page 4 of 4 having jurisdiction or by the Director of Distribution or both. In no case shall the temporary paving project more than 2 inches above grade line bed. See C-170 for instructions regarding permanent paving. Excess materials not used for backfill shall be removed from the job site so that the area is clean and neat at the completion of the Work. Upon completion and before final acceptance of Contract Work, the Contractor shall restore, in an acceptable manner, all property both public and private damaged under the prosecution of the work and shall leave the site and/or adjacent highway in a neat and presentable condition satisfactory to the Director of Distribution and local authority. 4. PERSONNEL SAFETY: All employees shall be protected with personal protective equipment for the protection of head, eyes, respiratory organs, hands, feet and other parts of the body as required. Employees exposed to vehicular traffic shall be provided with and instructed to wear special clothing or warning vests marked with or made of reflectorized or highly visible material. Personnel shall not be permitted under loads handled by power equipment and shall be required to stand away from any vehicle being loaded or unloaded.

59 MAINS C-170-1/2 PERMANENT PAVING AND SURFACE RESTORATION 1. PERMANENT PAVING Prior to the installation of the permanent paving any settlement or breaking up of temporary pavement shall be remedied and if the Work was done by a Contractor, the repairs shall be made at the Contractor's expense. Within six (6) months upon completion of the settlement of the backfill resulting from the closing of a trench or excavation, the temporary paving shall be removed and permanent paving shall be installed. The locations of the valve boxes, test boxes, etc., shall be furnished to the Contractor prior to removal of the temporary paving and boxes shall be adjusted to the elevation of the permanent paving. Any boxes which have been properly defined that are covered by permanent paving shall be located and reset at the Contractor's expense. Permanent paving shall meet the requirements of the Massachusetts Department of Telecommunications and Energy Standard and the requirements of the City, County, or other public or private authority having jurisdiction. 2. SOD In locations covered by established sod, the sod shall be cut and later replaced with a minimum of injury to its growth or appearance, or the area shall be re-loamed and reseeded. If trenching is done by a Contractor, the area shall be maintained by the Contractor for a period of 60 days of growing season to ensure growth thereafter.

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61 MAINS C-172-1/4 HANDLING AND INSTALLATION OF COATED AND WRAPPED STEEL PIPE 1. STORAGE Coated pipe shall be stored on racks with skids placed as shown in Figure 1, or on plastic covered sand rows where possible as shown in Figure 2. Coated two inch and service pipe may be laid on racks or on level ground free from stones and debris. Ends shall be kept above the ground to prevent the entrance of foreign material. If four inch single length and larger pipe is placed on padded skids, the skids are to be placed no more than twenty feet apart. Pipe may be pyramided on skids with suitable chock blocks provided. Pipe should be issued in approximately the same order as received, therefore, use small piles and do not add new pipe to existing piles. End bevels shall be protected during storage. 2. LOADING AND UNLOADING Four inch and larger coated pipe shall be loaded and unloaded with mechanical equipment using belt type slings, hooks in the pipe ends or other approved equipment designed to prevent damage to the coating. The use of chains, wire rope, or other pipe handling equipment which may injure the coating is prohibited. Coated pipe shall not be dragged, dropped or scraped against other pipe or hard objects while loading or unloading. 3. TRANSPORTATION Caution shall be taken to prevent any damage to the coated pipe during transportation. Trucks carrying coated pipe shall have racks and fastening equipment padded to prevent coating damage. When unloading pipe by hand it may be rolled down from the side of the truck on suitable skids using snubbed ropes. The pipe shall not be dropped or dragged off the side of the truck or allowed to roll down without the use of rope snubs. 4. STRINGING AND ON THE JOB HANDLING Four inch and larger coated pipe shall be kept on skids at all times. Skids should be placed under the cutback. Coated pipe should be lifted and carried into position, dropping and dragging is prohibited. Avoid damaging one length of pipe with the end of another. 5. ASSEMBLY Where conditions permit, pipelines may be assembled and aligned on suitable temporary supports over or along side the trench, welded, inspected, and coated. The assembly will then be lowered into the trench. Where this is not possible, each length shall be lowered into the trench. 6. INSPECTION A visual and/or electrical inspection of all coated pipe shall be made prior to lowering in the ditch. Holidays and damaged area shall be plainly marked and repairs made in accordance with (C-158). If pipe has been stockpiled for a considerable length of time and the quality of the coating is questionable, the coating is to be tested with a holiday detector.

62 C-172-2/4 MAINS HANDLING AND INSTALLATION OF COATED AND WRAPPED STEEL PIPE 7. BEFORE BACKFILLING The pipe shall preferably be supported in the bottom of the trench on undisturbed earth or well compacted soil or sand. Where this is not possible, the pipe may be set to grade on sand bags. Wooden blocks shall not be left in the trench. Solid rock shall be padded with earth free from rock or with sand to a minimum depth of four inches so that the pipe will be protected from any points of rock. All loose rocks, wood, welding rods, construction debris, etc., must be removed before lowering pipe into the ditch. Care should be taken to prevent the pipe from swinging against or rubbing on the side of the trench. The main should be installed with a desired minimum clearance of twelve inches from other gas facilities or from other underground structures of the company, city or other utilities, to allow proper maintenance and to protect against damage. Less than twelve inch clearance may be allowed by the Company Representative provided proper precautions are taken. In no case is physical contact allowable. Care shall be taken to keep the pipe internally clean. Foreign objects, rust, and scale shall be swabbed and blown out before assembly. The open ends of the line shall be securely closed with suitable end fittings at the end of each day's work to prevent the entrance of any foreign materials or other obstructions and shall not be reopened until the work recommences. When completed, the line must be left entirely free from water, dirt, obstructions and other foreign substances. Installation of main line valves, drips and branches shall be made after the line has been cleaned except where cleaning does not interfere with the fittings. Before installing gaskets, the faces of the flanges must be entirely clean of all dirt, paint, varnish, rust, or other foreign material and must be in alignment before tightening bolts. Pipe shall be installed with due consideration and allowance made for expansion. If bolted compression couplings are used for this purpose, or for any reason, refer to (C-127). See (C-122) for direction changes in the pipeline. After testing (see C-186) all bare steel pipe and fitting shall be coated and the line cathodically protected as covered in (C-500) series. See (C-150) for excavation and backfilling.

63 MAINS C-172-3/4 HANDLING AND INSTALLATION OF COATED AND WRAPPED STEEL PIPE FIGURE 1: PIPE STORAGE ON PADDED SKIDS NOTES Maximum Number of Tiers Diameter Number of Coal Tar Extruded Epoxy (Inches) Supports Coating Polyethylene Coating ¾" & 1" ½ " and smaller length pipe requires three supports which are within 1/3 inch of a straight line. 4" and larger single length pipe should be supported on two supports only. 4" and larger double length pipe should be supported on three supports. 2. For on job storage utilizing sand bags or polyethylene covered sandrows for support (see Figure 2, page C172-4/4).

64 C-172-4/4 MAINS HANDLING AND INSTALLATION OF COATED AND WRAPPED STEEL PIPE FIGURE 2: PIPE STORAGE ON PLASTIC COVERED SAND ROWS

65 MAINS C-173-1/4 HANDLING AND INSTALLATION OF PLASTIC PIPE 1. STORAGE Coiled plastic pipe shall be stored on pallets and straight lengths shall be stored off the ground on racks or blocking. Ends shall be kept above the ground and shall be securely closed to prevent the entrance of foreign material. Straight lengths shall be placed on a minimum of five blocks with a maximum overhang of three feet on each end. Pipe should be issued in approximately the same order as received. Black polyethylene covering shall be used when plastic pipe is exposed to ultra-violet radiation (sunlight) for periods greater than one year. If there is any apparent degradation as evidenced by excess discoloration, surface cracking or crazing, a sample must be returned to the manufacturer for evaluation before the pipe is issued. Stacking heights shall be as described below. Coiled Pipe Coiled pipe should be stored as received in silo packs. Individual coils can be removed from the silo pack without disturbing the stability of the package. Bulk Packs Pipe received in bulk packs or strip load packs should be stored in the same package. If the storage site is flat and level, bulk packs or strip load packs may be stacked evenly upon each other to an overall height of about 6. For less flat or less level terrain, stacking height should be limited to about 4. Before removing individual pipe lengths from bulk packs or strip load packs, the pack must be removed from the storage stack and placed on the ground. Loose Pipe Individual pipes may be stacked in rows. Pipes should be laid straight, not crossing over or entangled with each other. The base row must be blocked to prevent sideways movement or shifting. Loose pipe should be placed on wooden dunnage at least 4 inches wide and evenly spaced at intervals of about 6 feet beginning about 2 feet from the end of the pipe. The interior of stored pipe should be kept free of debris and other foreign matter. Suggested Loose Storage Stacking Heights for PE Pipe Nominal PE Pipe Size Suggested Stacking Height Rows Above DR 17 DR 17 and Below Suggested stacking heights based on 6 for level terrain and 4 for less level terrain.

66 C-173-2/4 MAINS HANDLING AND INSTALLATION OF PLASTIC PIPE 2. LOADING AND UNLOADING Bundled straight lengths and full coils of plastic pipe shall be loaded and unloaded with mechanical equipment using belt type slings, padded jaws or other approved equipment designed to prevent damage to the pipe. Plastic pipe shall not be dragged, dropped or scraped against hard objects while loading or unloading. 3. STRINGING AND ON THE JOB HANDLING OF COILED PIPE When uncoiling by hand, cut only those straps on the coil which are necessary to uncoil outer rolls. Cut internal bands whenever necessary as the coil is unrolled. String the pipe out on the ground upon arrival at the job site to allow time for the coil set to relax. Pipe should be lifted and carried into position. Dropping and dragging is prohibited. Reel trailers can be helpful when stringing coiled pipe for direct burial or insertion renewal. 4. STRINGING AND ON THE JOB HANDLING OF STRAIGHT LENGTH PIPE Straight lengths of plastic pipe shall be protected at all times. After the completion of the fusion process the plastic pipe should be lifted and carried into position. Dropping and dragging is prohibited. 5. INSPECTION Always inspect the pipe during all phases of handling and installation to make sure there are no defects due to manufacturing or damage that might have occurred during shipment and subsequent handling at the job site. Kinking or buckling should be avoided and any section of pipe which has been damaged in this manner shall be cut out. If a scratch or gouge has a depth greater than 10% of the minimum pipe wall thickness the section shall be removed. 6. ON SITE STORAGE When possible, plastic pipe should be stored in a shaded area at the job site to minimize the temperature difference between the pipe and soil. The size and complexity of the project will determine pre-installation storage requirements. For some projects, several storage or staging sites along the right of way may be appropriate, while a single storage location may be suitable for another job. The storage area should provide adequate protection against physical damage to components. It should be large enough to accommodate piping components as well as allow handling equipment to move about freely. The storage area should have a relatively smooth, level surface free of stones, debris or other materials that could damage the pipe or fittings. Where adequate ground conditions do not exist or when a bed cannot be prepared, the pipe may be placed on planking. The planking should be evenly spaced along the pipe length.

67 MAINS C-173-3/4 HANDLING AND INSTALLATION OF PLASTIC PIPE When pipes of variable wall thickness are received, it recommended that the pipe be segregated into piles, each pile containing a single size and pressure rating to minimize confusion at a later date. The thickest pipe should always be stored at the bottom of the pile. Furthermore, the pile should be constructed in a pyramidal, freestanding manner, with each successive layer having one less pipe than the layer below. The bottom layer should be braced to prevent movement. The maximum allowable stacking heights for PE pipe should not exceed those in the table above. 7. BEFORE BACKFILLING The pipe shall be supported in the bottom of the trench on undisturbed earth free of rock and debris or on well compacted soil, sand or stone dust. When ledge, rock, hardpan or boulders are encountered, the bottom of the trench should be padded with sand or other fine grained fill materials. Pipe where joined to fittings should be laid true to line and grade, and backfilled carefully to prevent differential settlement, and thus excessive bending. The pipe should be laid in the trench with slack so that the thermal contraction or external loading will not place unnecessary stress or tensile pull on the piping or joints. As an additional precaution to minimize thermal contraction stresses, a minimum time of one hour "cool down" in place is recommended prior to backfilling or making the physical tie-in to existing pipe. The pipe should be installed with a desired minimum clearance of twelve inches from other gas facilities or from other underground structures of the company, city or other utilities, to allow proper maintenance and to protect against damage. Less than twelve inch clearance may be allowed by the Company Representative provided proper precautions are taken. In no case is physical contact allowable. Care shall be taken to keep the pipe internally clean. Foreign objects shall be swabbed and blown out before assembly. The open ends of the line shall be securely closed with suitable end fittings at the end of each day s work to prevent the entrance of any foreign material or other obstructions and shall not be reopened until the work recommences. Installation of main line valves and branches shall be made after the line has been cleaned except where cleaning does not interfere with the fittings. See (C-150) for excavation and backfilling. 8. SPECIAL PRECAUTION To prevent damage by chemical action care shall be taken so that cleaning solutions, detergents, solvents, alcohols, oils, etc., do no come in contact with plastic pipe and fittings. The use of soap or commercially prepared leak detecting solutions is permitted when used for testing or leak detection at joints or connections.

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69 MAINS C-180-1/2 CLEANING STEEL MAINS BY PIGGING During the installation of steel mains it is possible to accumulate debris in the pipe that can adversely affect the distribution system. All mains should be handled and installed in accordance with C-172, and an internal visual inspection of the individual joints of pipe be made prior to welding or assembly. It is recommended that all steel mains 2 inch and larger having a length of over 100 feet be internally cleaned by pigging. Pigs for cleaning are propelled by a pressure differential created by loading the pipe upstream of the pig with air. Normally, a compressor capacity of 100 c.f.m. and 90 PSIG will be suitable to propel the pig. The following information shall be used as a guide for pigging work: 1. Pig selection shall be made on the basis of test results or prior experience and may be fabricated from a combination of brushes, spacers, and urethane cups or from resilient high density polyurethane foam wrapped with spiral, long wearing, plastic. Pig design should allow traversing of elbows, tees, valves and other fittings wherever such may be encountered. 2. Pigging shall be planned so that no pipe line obstructions are encountered which will block the pig's passage as it traverses through the pipe. Manufacturer's instructions and recommendations should be followed during pigging operations. 3. The pipe line shall be in the trench and backfilled, except for the terminal ends, before pigging. 4. The launching end of the pipe shall be properly sealed by a welding cap, plate, or valve with provision for introducing air upstream of the pig after being placed in its starting position. 5. Observers may be stationed over and along the route to listen for the pig's progress and to help spot its location should a stoppage occur. 6. Suitable means of receiving the pig without damage to persons or property shall be provided at the receiver end before pigging is started. The slotted pig receiver, illustrated in this standard, is strongly recommended for all pipe sizes; however, depending on local conditions, the use of sandbags, timber, blasting mats or digging machine bucket, properly placed, may be substituted. A canvas or plastic cover should fully shield the receiver end to contain the blowing of rust, dust and scale. 7. All personnel and the public shall be kept clear of the receiving end by placing a perimeter barrier a safe distance away.

70 C-180-2/2 MAINS CLEANING STEEL MAINS BY PIGGING FIGURE 1: TYPICAL PIG RECIEVER SLOT DETAIL Diameter (Inches) Slot "L" (Inches) Slot "W" (Inches) Number of Slots Required ½ 2 2 2½ 2½ 2½ NOTES a. Receiver shall have the same I.D. as pipe to be cleaned. b. Remove all projections from slots inside of the receiver.

71 GAS OPERATIONS CONSTRUCTION C-186 MAINS - PRESSURE TESTING Revision: 1 Date Issued: 04-DEC-2012 Page 1 of 3 1. GENERAL a. The test medium will normally be air, inert gas or water (hydrostatic). b. Mains will be pressure tested according to Sections 3 through 8 of this standard. Once the main is pressurized to the test pressure, the test medium source must be disconnected. c. Mains may be tested in sections. For steel mains, standard weld caps of the same pipe schedule as that being tested or flat plate test heads (constructed and installed in accordance with C-146) should be welded to the ends of the section to be tested. All welds must be the same strength and quality as other pipe joints. Upon completing the test, the weld caps or flat plate test heads, including the welds, shall be cut off from the test section. Mechanical end caps, either positive or nonpositive restraint, are not to be used for testing unless previously approved by the Area Manager or Director of Distribution. Plastic mains shall always be tested with electrofusion or butt-fusion end caps. d. Main sections longer than 1,000 feet shall be tested for an extended period of time, at least 24 hours with the same test pressure requirements as shorter sections. A pressure chart recorder shall be used. e. Loss of pressure due to leakage during a test shall be treated as a failure and must be investigated and resolved. Once leaks have been repaired, the gas main can be pressure tested again. f. If the main is not to be immediately placed in service, air or inert gas shall be left in the main at a reduced pressure as directed by the Area Manager or Director of Distribution. Otherwise upon completion of testing, the main or section shall be blown down, properly purged, and placed in service. g. Tie-in connections shall be non-destructively tested or soap tested at the available line pressure. 2. SAFETY a. Safety (company. contractor and public) is the primary concern when performing a pressure test. b. Properly installed positive restraint end caps or fused or welded end caps will be used during the test. c. In the event that use of a non-positive restraint end cap is approved, it must be secured according to the procedure for installing and welding a restraint assembly, C-127. d. At all times, when any mechanical end cap is used, personnel will be directed to evacuate the trench and stand clear of the downstream side of the end cap while the line is pressurized. Precautions will be taken to secure the area downstream of the end cap to protect the public.

72 GAS OPERATIONS CONSTRUCTION C-186 MAINS - PRESSURE TESTING Revision: 1 Date Issued: 04-DEC-2012 Page 2 of 3 e. In the event any mechanical end cap leaks during the pressure test, the line will be blown down completely prior to personnel entering the excavation to make adjustments on the end cap. 3. STEEL MAINS TO BE OPERATED BELOW 100 PSIG a. Steel mains to be operated below 100 psig shall be tested for tightness to at least 1.5 times MAOP or at least 90 psig, whichever is greater, for at least one hour. Loss of pressure due to leakage during the test is not permitted. 4. STEEL MAINS TO BE OPERATED BETWEEN 100 PSIG AND 200 PSIG (INCLUSIVE) AND AT A HOOP STRESS OF LESS THAN 30% OF SMYS a. Steel mains to be operated between 100 psig and 200 psig (inclusive) and at a hoop stress of less than 30% of SYMS shall be tested for tightness to 1.5 times the MAOP for at least four hours. Loss of pressure due to leakage during the test is not permitted. b. If the main is to be stressed in excess of 20% SMYS during the test and inert gas or air is the test medium, a leak test must be made between 100 psig and 20% SMYS or the line walked to check for leaks while hoop stress is held at approximately 20% SMYS. c. Calibrated recording instruments verified by dead weight instruments are to be used and the recording submitted to the Massachusetts Department of Public Utilities for certification that the steel main, as defined, may be operated at a pressure which is equal to the test pressure divided by a factor of 1.5. The pressure test may be witnessed by the D.P.U. 5. STEEL MAINS TO BE OPERATED ABOVE 200 PSIG AND AT A HOOP STRESS OF LESS THAN 30% OF SYMS a. Steel mains to be operated above 200 psig and a hoop stress of less than 30% of SMYS shall be tested for tightness to at least 1.5 times the MAOP for at least eight hours. Loss of pressure due to leakage during the test is not permitted. b. If the main is to be stressed in excess of 20% SMYS during the test and inert gas or air is the test medium, a leak test must be made between 100 psig and 20% SMYS or the line walked to check for leaks while hoop stress is held at approximately 20% SMYS. c. Calibrated recording instruments verified by dead weight instruments are to be used and the recording submitted to the Massachusetts Department of Public Utilities for certification that the steel main, as defined, may be operated at a pressure which is equal to the test pressure divided by a factor of 1.5. The pressure test may be witnessed by the D.P.U.

73 GAS OPERATIONS CONSTRUCTION C-186 MAINS - PRESSURE TESTING Revision: 1 Date Issued: 04-DEC-2012 Page 3 of 3 6. STEEL MAINS TO BE OPERATED AT A HOOP STRESS OF 30% OR MORE OF SMYS a. Steel mains to be operated at a hoop stress of 30% or more of SYMS, shall be strength tested in accordance with 29CFR , and PLASTIC MAINS a. Plastic mains shall be tested to at least 1.5 times the MAOP or at least 90 psig, which ever is greater, for at least one hour. The test pressure may not exceed three times the design pressure of the pipe. The temperature of thermoplastic material must not exceed 100 F during the test. Loss of pressure due to leakage during the test is not permitted. 8. RECORDS a. All test records for mains with an MAOP greater than or equal to100 psig shall be retained for the lifetime of the main. (Mains tested under Paragraphs 4, 5 and 6) b. The Activity Report must contain at least the following: i. The name NSTAR Gas, the printed name and signature of the NSTAR Gas employee responsible for making the test, and the name of any test company used. ii. The test medium used. iii. The test pressure, measured in units of pounds per square inch, gauge (PSIG). iv. The time of day (hh:mm AM/PM) that the test was started. v. The time of day (hh:mm AM/PM) that the test was ended. vi. The test duration. vii. The pressure recording charts or other record of pressure readings. viii. Elevation variations, whenever significant for the particular test. ix. Leaks and failures noted and their disposition. c. All other main test records shall be retained for at least 5 years. (Mains tested under Paragraphs 3 and 7) d. Records must contain at least the following: i. The test medium used. ii. The test pressure, measured in units of pounds per square inch, gauge (PSIG). iii. The time of day (hh:mm AM/PM) that the test was started. iv. The time of day (hh:mm AM/PM) that the test was ended. v. The test duration. vi. The Company name and the printed name and signature of the person responsible for the pressure test. vii. Leaks and failures noted and their disposition.

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75 9NSTAR GAS GAS OPERATIONS CONSTRUCTION INDEX - SERVICES Date Issued: 04-DEC-2012 Page 1 of I I Document Number C C C C C C C C C C Document Title Services Curb Box Installation Low-Pressure Steel Service Installation Current Revision o o Installation of Intermediate-Pressure Steel Services Above 2 PSIG but not greater than 60 PSIG Fabrication of Steel Service Entrance Bends for Basement 0 less Buildings - Meter Inside Building Installation of High-Pressure Steel Service Above 60 PSIG but less than 285 PSIG Installation of Direct-Burial Plastic Services 60 PSIG or less Service Replacement by Plastic Insert 60 PSIG or less Sizing Services Testing Gas Services o o o o o 1 Revision Date 07-MAR /25/ / DEC-2012 Approved by; tz,)..m/}~ Approved dale:

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77 SERVICES C-200-1/2 SERVICES 1. The purpose of these Standards is to provide uniform practices and minimum requirements for the installation of gas services. These Standards are designed to comply with the requirements for the transportation of gas as set forth in the rulings of the Department of Transportation Title 49, Part 192 and the rules of the Massachusetts Department of Telecommunications and Energy 220 CMR 100, and revisions thereto. 2. A gas service includes the connection to the main, all pipe, fittings, devices and appurtenances up to and terminating with the customers meter or the connection to the customer's piping, whichever is farther downstream. C-200 addresses from the main to the inside or outside shutoff. C-300 addresses customer metering and regulation. 3. For purposes of these Standards, there are three Pressure Classifications for Services as follows: a. Low-Pressure Services: Those which operate at pressures of 2 PSIG or less. b. Intermediate-Pressure Services: Those which operate at pressures above 2 PSIG but not greater than 60 PSIG. c. High-Pressure Services: Those which operate at pressures above 60 PSIG but not greater than 200 PSIG. 4. It is the intent of these Standards that service connections to the mains shall be made without blowing gas, except when not possible on low pressure only. Deviations from this practice shall require the prior approval of the Director of Distribution. 5. Approval of the Massachusetts Regulatory Board is required before more than one service is supplied to any building. Utility gas and propane gas systems shall not be installed within the same building except where authorized by the Board. 6. Lines with a maximum allowable operating pressure in excess of 200 PSIG MAOP are considered to be a special case and are not generally covered by these standards. All installation and design modifications on this class line must comply with the Massachusetts Department of Telecommunications and Energy 220 CMR 109 and must be reviewed by the Engineering Department.

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80 SERVICES C-206-1/2 CURB BOX INSTALLATION 1. This Standard applies to the installation of boxes which protect and give access to cocks, gates, drip risers and test stations installed underground adjacent to roadways, streets, or anywhere not subjected to heavy traffic. See M All boxes shall have an inside box diameter sufficient to provide access and working space as required. 3. All boxes shall be installed so that surface loads cannot be transmitted to the pipeline. 4. The top of the box shall be set to conform with the finish grade in the immediate area. 5. Test wires should not be installed in curb boxes used for other purposes. They may be brought up outside of the box extension and enter the box just below the cast iron head.

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82 GAS OPERATIONS CONSTRUCTION Revision: 1 Date Issued: 07-MAR-2012 C-210, LOW-PRESSURE STEEL SERVICE INSTALLATION Page 1 of 4 FIGURE 1: TYPICAL LOW-PRESSURE STEEL SERVICE INSTALLATION 1 Existing Main 2 Inlet Service Connection (M-143) or Welded XH Coupling or Thread-olet (M- 138) 3 Plastic Warning Tape (M-269) 4 Compression End Street Elbow (M-123), Butt Welding Elbow (M-137), or Insulated Compression Coupling (M-121 or M-123) 5 Weld End Insulator (M-125) if Item 4 is not of the insulating type 6 Coated Steel Service (M-251, 261, 262) 7 Valve Box (M-25) 8 Curb Cock (M-51) 9 Approved Tape (M-77) 10 Prefabricated Meter Fit (M-206) or Insulated Shut-Off (M-53) NOTES a. Plastic services shall be installed wherever possible. Steel services shall be installed only with the permission of the Director of Distribution. See Pages 2 through 4 for details of main connections and building entrance. b. Slope service toward the main whenever possible. c. Minimum depth of service is to be twelve inches (12") on private property and eighteen inches (18") on streets and roads, and the service is to be laid in a firmly packed (preferably undisturbed) trench bottom. d. Coated Steel service pipe shall be cathodically protected in accordance with C-500. e. Outside shut-offs shall be installed on all services. (May be component of prefabricated meter fit assembly.) f. For sizing steel services, see C-240. g. Exterior service riser shall be tape-wrapped with a fifty percent (50%) overlap for four inches (4") before the bend and extend two inches (2") above finish grade. h. Inside installation not permitted without prior approval of the Director of Distribution. i. Yellow Plastic Warning Tape stating in black letters "CAUTION - BURIED GAS LINE BELOW" to be installed approximately one (1) foot below the finished grade. j. Warning tape and sand are not required for services installed by trenchless methods. Tracer wire is to be installed along with service.

83 GAS OPERATIONS CONSTRUCTION Revision: 1 Date Issued: 07-MAR-2012 C-210, LOW-PRESSURE STEEL SERVICE INSTALLATION Page 2 of 4 FIGURE 2: TYPICAL LOW-PRESSURE STEEL SERVICE CONNECTIONS TO CAST IRON MAINS 6 INCH AND SMALLER DIAMETER MAIN CONNECTIONS - SLEEVE REQUIRED OR RECOMMENDED 1. Existing Cast Iron Main 2. Mechanical Sleeve (M-150) 3. Threaded Inlet Service Connection (M-143) 4. Compression End Street Elbow (M-123), Butt Welding Elbow (M-137), Threaded Elbow or Street Elbow (M-138), or Insulated Compression Coupling (M-121 or M-123) 5. Weld End Insulator (M-125) if Item 4 not insulating type 6. Coated Steel Service (M-251, 261, 262) 6 INCH OR LARGER DIAMETER SLEEVE OPTIONAL OR NOT REQUIRED NOTES a. Install Inlet Service Connection on main. b. Threaded taps in cast iron pipe are permitted without reinforcement to a size not more than 25% of the nominal diameter of the pipe except that a 1¼ inch tap may be made in a 4" cast iron or ductile iron pipe without reinforcement. In areas where soil and service conditions may create unusual external stresses on cast iron pipe, unreinforced taps may be used only on 6" diameter or larger pipe. On larger taps mechanical sleeves shall be used. c. Install Inlet Service Connection on main vertically as shown, or anywhere on or above the horizontal pipe centerline as required for depth of cover. d. For services larger than 2", see C-120.

84 GAS OPERATIONS CONSTRUCTION Revision: 1 Date Issued: 07-MAR-2012 C-210, LOW-PRESSURE STEEL SERVICE INSTALLATION Page 3 of 4 FIGURE 3: TYPICAL LOW-PRESSURE STEEL SERVICE CONNECTIONS TO STEEL MAINS 1. Existing Steel Main 2. Mechanical Sleeve (M-150) 3. Welded Inlet Service Connection (M-143) or Threaded Inlet Service Connection (M- 143) with XH Welded Coupling or Thread-olet (M-137) 4. Compression End Street Elbow (M-123), Butt Welding Elbow (M-137), Threaded Elbow or Street Elbow (M-138), Insulated Compression Coupling (M-121 or M-123) NOTES a. Weld Inlet Service Connection to main. b. Inlet Service Connection is to be welded to main vertically, as shown, or anywhere on or above the horizontal pipe centerline as required for depth of cover. Reinforcing saddle or Weld-olet type fitting may be used where extra strength is desired. c. For services larger than 2", see C Weld End Insulator (M-125) or Insulated Compression Coupling (M-123) if Item 4 not insulating type 6. Coated Steel Service (M-251, 261, 262)

85 GAS OPERATIONS CONSTRUCTION Revision: 1 Date Issued: 07-MAR-2012 C-210, LOW-PRESSURE STEEL SERVICE INSTALLATION Page 4 of 4 (Inside installation not permitted without prior approval of the Director of Distribution) FIGURE 4: TYPICAL BUILDING ENTRANCE INSTALLATION 1. Inside Shut-Off (M-53) 2. Approved Tape (M-77) 3. Approved Fittings (M-133) 4. Approved Prefabricated Steel Services Entrance Bend (C-214) 5. Vent Cap (M-209) (not illustrated) NOTES a. All service openings through walls, foundations, or floors shall be made as neatly as possible. When the service is in place, the opening shall be sealed at the foundation wall to prevent entry of gas or water. b. Extra pipe protection in the wall shall be provided by a tape wrap applied with a 50% overlap for at least one inch (1") beyond the wall face. c. Steel service entrance bend (C-214-2/2) if used - shall be taped-wrapped with a 50% overlap for the entire length of the bend below the floor to two inches (2") above the floor. d. The vent shall be 3/4" diameter pipe extended from a 3/4" x 2" long nipple. The open end of the vent shall terminate with a rain and insect resistant fitting external to the building and be located such that any gas release will occur away from any openings into the building.

86 SERVICES INSTALLATION OF INTERMEDIATE-PRESSURE STEEL SERVICES ABOVE 2 PSIG BUT NOT GREATER THAN 60 PSIG C-212 Page 1 of 4 FIGURE 1: TYPICAL INTERMEDIATE-PRESSURE STEEL SERVICE INSTALLATIONS 1. Existing Main 2. Inlet Service Connection (M-143) 3. Plastic Warning Tape (M-269) 4. Butt Welding Fitting (M-137) 5. Weld End Insulator (M-125) or Insulated Compression Coupling (M-121) 6. Coated Steel Service (M-251, 261, 262) 7. Valve Box (M-25) 8. Outside Shut-Off (M-51) 9. Approved Tape (M-77) 10. Prefabricated Meter Fit (M-206) or Insulated Shut-Off (M-53) 11. Excess Flow Valve (M-306) NOTES a. The above drawing is representative of a typical intermediate-pressure service installation. See Pages 2 through 4 for detail of main connections and building entrance. b. Slope of service shall be toward the main whenever possible. c. Minimum depth of service is to be twelve inches (12 ) on private property and eighteen inches (18 ) on Streets and Roads and the service is to be laid in a firmly packed (preferably undisturbed) trench bottom. Backfill shall be free of building material and trash. d. Coated steel service pipe shall be in accordance with M-251 and M-261 or M-262, and shall be cathodically protected in accordance with C-500. e. Outside shut-offs shall be installed on all immediatepressure services. f. For sizing steel service, see C-240 g. Exterior service riser shall be tape-wrapped with 50% overlap for four inches (4 ) before the bend and extend two inches (2 ) above the finished grade h. Inside installation not permitted without prior approval of the Director of Distribution. i. Yellow Plastic Warning Tape stating in black letters CAUTION BURIED GAS LINE BELOW to be installed approximately one (one) foot below the finished grade. j. Warning tape and sand are not required for services installed by trenchless methods. Tracer wire is to be installed along with the service. k. The builder or developer is responsible to identify final grade with a permanent mark on the foundation if final grade is not established at time of service installation. l. Riser shall be installed such that the service valve (item 10) is at least 12 above final grade or the final grade mark made by the builder. On IP services there must be a minimum of 12 clearance (18 recommended) from the bottom of the regulator vent to the finished grade. Regulator vents shall be free and clear of any obstruction that may interfere with proper operation. Revised Revised Revised Revised Revised 3/25/10 Date RJB By Date By Date By Date By Date By

87 SERVICES INSTALLATION OF INTERMEDIATE-PRESSURE STEEL SERVICES ABOVE 2 PSIG BUT NOT GREATER THAN 60 PSIG C-212 Page 2 of 4 FIGURE 2: TYPICAL INTERMEDIATE-PRESSURE STEEL SERVICE CONNECTIONS TO CAST OR DUCTILE IRON MAINS 1. Existing Cast Iron Main 2. Mechanical Sleeve (M-150) 3. Threaded Inlet Service Connection (M-143), Butt Welding Elbow (M-137), Threaded Ell or Street Ell (M-138) 4. Weld End Insulator (M-125) or Insulated Compression Coupling (M-121) 5. Coated Steel Service (M-251, 261, 262) 6. Excess Flow Valve (M-306) NOTES a. To install Inlet Service Connection on main. b. Threaded taps in cast iron pipe are permitted without reinforcement to a size not more than 25% of the nominal diameter of the pipe except that 1 ¼ inch tap may be made in a 4 inch cast iron or ductile iron pipe without reinforcement. In areas where soil and service conditions may create unusual external stresses on cast-iron pipe, un-reinforced taps may be used only on 6 diameter or larger pipe. On larger taps, mechanical sleeves shall be used. c. Install Inlet Service Connection on main vertically as shown, or anywhere on or above the horizontal pipe centerline as required for depth of cover. d. For services larger than 2, see C-120. Revised Revised Revised Revised Revised 3/25/10 Date RJB By Date By Date By Date By Date By

88 SERVICES INSTALLATION OF INTERMEDIATE-PRESSURE STEEL SERVICES ABOVE 2 PSIG BUT NOT GREATER THAN 60 PSIG C-212 Page 3 of 4 FIGURE 3: TYPICAL INTERMEDIATE-PRESSURE STEEL SERVICE CONNECTIONS TO STEEL MAINS 1. Exiting Steel Main 2. Welded Inlet Service Connection (M-143) 3. Weld End Insulator (M-125) or Insulated Compression Coupling (M-121) 4. Coated Steel Service (M-251, 261, 262) 5. Excess Flow Valve (M-306) NOTES a. Weld Inlet Service Connection to main. b. Inlet Service Connection is to be welded to the main vertically as shown, or anywhere on or above the horizontal pipe centerline as required for depth of cover. Reinforcing saddle or Weld-o-let type fitting may be used where extra strength is desired. c. For services larger than 2, see C-118. Revised Revised Revised Revised Revised 3/25/10 Date RJB By Date By Date By Date By Date By

89 SERVICES INSTALLATION OF INTERMEDIATE-PRESSURE STEEL SERVICES ABOVE 2 PSIG BUT NOT GREATER THAN 60 PSIG C-212 Page 4 of 4 (Inside installation not permitted without prior approval of the Director of Distribution) FIGURE 4: TYPICAL BUILDING ENTRANCE INSTALLATION 1. Inside Shut-Off (M-53) 2. Approved Tape (M-77) 3. Approved Fittings (M-133) 4. Approved Prefabricated Steel Service Entrance Bend (C-214) 5. Vent Cap (M-209) (not illustrated) NOTES a. All service entrance openings through walls, foundations, or floors shall be made as neatly as possible. When the service is in place, the opening shall be sealed at the foundation wall to prevent entry of gas or water. b. Extra pipe protection in the wall shall be provided by a tape wrap applied with a 50% overlap for at least one inch (1 ) beyond the wall face. c. Steel service entrance bend (C-214-2/2) if used shall be tape-wrapped with a 50% overlap for the entire length of the bend below the floor to two inches (2 ) above the floor. d. The vent shall be ¾ diameter pipe extended from a ¾ x 2 long nipple. The open end of the vent shall terminate with a rain and insect repellant fitting and be located such that any gas release will occur away from openings into the building. e. The service must be insulated inside the building as close to the service entrance as possible. Revised Revised Revised Revised Revised 3/25/10 Date RJB By Date By Date By Date By Date By

90 SERVICES C-214-1/2 FABRICATION OF STEEL SERVICE ENTRANCE BENDS FOR BASEMENT LESS BUILDING - METER INSIDE BUILDING (Inside installation not permitted without prior approval of the Director of Distribution) FIGURE 1: OPTION 1 FABRICATED ENTRANCE BEND NOTES a. Pipe and sleeve are to be uncoated Standard weight API-5L, A-53 or A-106 Specification and are to be field coated and taped (C-518). b. Weld sleeve to pipe. c. Sleeve shall be tested with air pressure and shall hold 100 PSI gauge for a period of not less than five (5) minutes. d. Dimensions shown as variable are to be determined in the field. e. See C-210, Page 4 or C-212, Page 4 for installing Service Entrance Bends. f. See M-137 for Steel Welding Fittings. g. Size of Sleeve: Service Sleeve ¾" 1¼" 1" 2" 1¼" 2" 1½" 2½" 2" 3" 3" 4" 4" 6" h. Install a sleeve vent using a 3/4" x 2" long nipple (threaded one end) on the meter side end of the sleeve. Run the vent line external to the building and terminate the vent line with a screened vent cap (rain and insect resistant) fitting. The vent should be located such that any gas release will occur away from any openings into the building.

91 C-214-2/2 SERVICES FABRICATION OF STEEL SERVICE ENTRANCE BENDS FOR BASEMENT LESS BUILDING - METER INSIDE BUILDING (Inside installation not permitted without prior approval of the Director of Distribution) FIGURE 2: OPTION 2 FABRICATED ENTRANCE BEND NOTES a. Pipe and sleeve are to be uncoated Standard weight API-5L, A-53 or A-106 Specification and are to be field coated and taped (C-518). b. Weld sleeve to pipe. c. Sleeve shall be tested with air pressure and shall hold 100 PSI gauge for a period of not less than five (5) minutes. d. Dimensions shown as variable are to be determined in the field. e. See C-210, Page 4 or C-212, Page 4 for installing Service Entrance Bends. f. See M-137 for Steel Welding Fittings. g. Size of Sleeve: Service Sleeve ¾" 1¼" 1" 2" 1¼" 2" 1½" 2½" 2" 3" 3" 4" 4" 6" h. Install a sleeve vent using a 3/4" x 2" long nipple (threaded one end) on the meter side end of the sleeve. Run the vent line external to the building and terminate the vent line with a screened vent cap (rain and insect resistant) fitting. The vent should be located such that any gas release will occur away from any openings into the building.

92 SERVICES INSTALLATION OF HIGH PRESSURE STEEL SERVICE ABOVE 60 PSIG BUT LESS THAN 285 PSIG C-216 Page 1 of 4 FIGURE 1: TYPICAL HIGH-PRESSURE SERVICE INSTALLATION (LAND SCAPED INSTALLATION) FIGURE 1a: ALTERNATE HIGH-PRESSURE SERVICE INSTALLATION (SIDEWALK AND PARKING LOT INSTALLATION) Revised Revised Revised Revised Revised 3/25/10 Date RJB By Date By Date By Date By Date By

93 SERVICES INSTALLATION OF HIGH PRESSURE STEEL SERVICE ABOVE 60 PSIG BUT LESS THAN 285 PSIG C-216 Page 2 of 4 NOTE: SEE FOLLOWING PAGES FOR MATERIALS AND NOTES Revised Revised Revised Revised Revised 3/25/10 Date RJB By Date By Date By Date By Date By

94 SERVICES INSTALLATION OF HIGH PRESSURE STEEL SERVICE ABOVE 60 PSIG BUT LESS THAN 285 PSIG C-216 Page 3 of 4 Revised Revised Revised Revised Revised 3/25/10 Date RJB By Date By Date By Date By Date By