Table of Contents Scope... 845 References... 845 Governmental... 845 EQT Midstream Publications... 845 Industry Standards... 846 Computer Programs... 846 1 Manufactured Branch Connections... 846 1.1 Extruded Headers... 846 1.2 Reducing and Straight Tees... 846 1.3 Sweepolet... 847 1.4 Line Stop Fittings... 847 1.5 Hottap Split Reinforcing Tees... 847 1.6 Olets... 847 1.6.1 Weldolet... 848 1.6.2 Threadolet... 848 1.6.3 Sockolet... 848 1.6.4 Latrolet... 849 1.6.5 Elbolet... 849 1.6.6 Nipolet... 850 1.6.7 Olet Conventional Run Size Combinations... 850 TABLE 1... 850 TABLE 2... 851 TABLE 3... 851 1.7 Reinforcing Members (for use with Field Fabricated Branch Connections)... 851 2 Welded Branch Connections... 852 2.1 In-Service Welded Branch Connection (Hot Tap)... 852 2.2 Special Considerations for Branch Connections... 854 Version Control... 855 Hot Tap and Branch Connections.doc Page 844 Revision / Save Date: 3/15/17
This document is intended for the employees of EQT Corporation and any of its direct or indirect subsidiaries who are qualified to understand and follow its contents. Any questions regarding the use of this document should be directed to the Director of Design Engineering, EQT Midstream. Scope The purpose of this design standard is to establish guidelines for the tapping of in-service natural gas and natural gas liquids pipelines, including regulated and non-regulated pipelines. This standard also covers the design requirements for welded branch connections and extruded outlets, including external loading concerns. References Governmental GOVERNMENT REGULATION REFERENCES Code of Federal Regulations (CFR) Title 49 CFR Part 192, Transportation of Natural and Other Gas by Pipeline: Minimum Federal Standards (PHMSA, DOT) Title 49 CFR Part 195, Transportation of Hazardous Liquids by Pipeline (PHMSA, DOT) EQT Midstream Publications EQT POLICY, STANDARDS, & PUBLICATIONS Design and Construction Standards 3.1 - Welding and Inspection Requirements 3.3 - Weld Procedure Qualifications and Requirements 9.1 - Strength Testing of Pipeline Facilities 3.5 - Joint Selection and Design Standard Operating Procedures MP 068 - Tapping a Pipeline MP 092 - Measure Pipe Thickness Using Ultrasonic Thickness Gauge 13.1 Pipeline Standard Drawings P-S-BARRED TEE-1197-01-2 Hot Tap and Branch Connections.doc Page 845 Revision / Save Date: 3/15/17
Industry Standards INDUSTRY STANDARDS ASME B31.8 Gas Transmission and Distribution Piping Systems, latest approved edition. ASME B31.4 Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids, Latest approved edition ASME Boiler and Pressure Vessel Code Section VIII, Division 1 Rules for Construction of Pressure Vessels MSS SP-75 Specification for High Test Wrought Butt Welding Fitting, latest approved edition Computer Programs COMPUTER PROGRAMS Computer Programs Pipeline Toolbox Reinforcement of Welded Branch Connections 1 Manufactured Branch Connections 1.1 Extruded Headers Shall be manufactured in accordance with ASME B31.8 or B31.4 as applicable Applicable to steel extruded outlets in which the reinforcement is integral, and the axis of intersection of the branch to header is perpendicular Not applicable to branch connections in which additional non-integral material is applied in the form of rings, pads or saddles The manufacturer shall be responsible for establishing and marking on the section containing extruded outlets, the design pressure, temperature, and that such were established under 49 CFR Part 192. The manufacturer s name or trademark shall also be marked on the section Extruded outlets manufactured in compliance with MSS SP-75 are in accordance with the requirements of this section 1.2 Reducing and Straight Tees Standard sizes are generally available with the branch size down to two pipe sizes below ½ the run size Should be used for new construction Used when pipeline can be removed from service Bars shall be installed in fittings for piggable applications, if branch size warrants Hot Tap and Branch Connections.doc Page 846 Revision / Save Date: 3/15/17
1.3 Sweepolet Piggable fittings with branches ½ the run size and larger shall be barred Tees requiring bars should be ordered as such; however field barring is acceptable (See P-S- BARRED TEE-1197-01-2) Standard sizes are available up to 2 pipe sizes below header pipe size A good option for small outlets in large high yield piping systems Can provide a more cost effective option than a weld tee Application and specifications to be determined by Design Engineering Reinforcement is integral to the fitting See Section 1.2 of this standard for barring information 1.4 Line Stop Fittings Used to make size-on-size in service tap when it is necessary to isolate a section of pipeline by the use of a line stop plugging operation. Shall be installed per Design and Construction Standard 3.1 Welding and Inspection Requirements. Shall be installed per all guidance and precautions of Section 2.1, In-Service Welded Branch Connections, of this standard. 1.5 Hottap Split Reinforcing Tees Used to make an in service hottap when the MAOP will generate a stess level in the main greater than 50% SMYS and when the branch nominal size exceeds ½ the run nominal size, see Section 2.2. 1.6 Olets Shall be installed per Design and Construction Standard 3.1 Welding and Inspection Requirements. Shall be installed per all guidance and precautions of Section 2.1, In-Service Welded Branch Connections, of this standard. Consider if fitting needs to be barred and consult with the vendor concerning barring the fittings for pigging. Sizes 2 - inches and smaller are acceptable; refer to Design Standard 3.5 Joint Selection and Design for application restrictions in the use of socket-weld type fittings. O lets shall be specified to meet design conditions, but at a minimum, weldolets shall be ordered as XS, and threaded o lets shall be ordered as 3000 PSI. Reinforcement is integral to the O let fitting Hot Tap and Branch Connections.doc Page 847 Revision / Save Date: 3/15/17
1.6.1 Weldolet A weldolet has a butt weld branch connection that s designed to minimize stress concentrations and provide reinforcement. Figure 1: Picture of a Weldolet 1.6.2 Threadolet A threadolet provides a threaded outlet branch connection and is manufactured in Class 2000 (not used by EQT), 3000 and 6000. 1.6.3 Sockolet Figure 2: Picture of a Threadolet Utilizes a weldolet design configuration with a socket welded outlet Figure 3: Picture of a Sockolet Hot Tap and Branch Connections.doc Page 848 Revision / Save Date: 3/15/17
1.6.4 Latrolet Used for 45 degree lateral connections and available in butt weld configurations. Available in 3000 PSI and 6000 PSI for socket weld and threaded applications Figure 4: Picture of a Latrolet 1.6.5 Elbolet Used on 90 degree elbows (LR or SR) for thermowell and instrumentation connections in a butt weld configuration Available in Class 3000 and 6000 for socket weld, threaded, and butt welded applications. Figure 5: Picture of a Elbolet Hot Tap and Branch Connections.doc Page 849 Revision / Save Date: 3/15/17
1.6.6 Nipolet A one piece fitting for valve take-offs, drains and vents. Manufactured for Extra Strong and Double Extra Strong applications in 3 " to 6 " lengths. Available with male-socketweld or male threaded outlets. Figure 6: Picture of a Nipolet TABLE 1 Run Sizes 1.6.7 Olet Conventional Run Size Combinations The tables in this section provide olet outlet sizes in inches for various run (header) pipe sizes. The following table applies to standard weight weldolet, extra strong weldolet, Class 3000 threadolet, Class 3000 sockolet, and extra strong nipolet. Outlet Size Inches 1/8 1/4 3/8 3/4 1 1 1/4 1 2 3/8 3/8 3/4 1 1 1/4 1 2 1 3/4 3/4 1 1 1/4 1 2 2 1 3/4 1 3/4 1 1/4 to 1 1/4 to 1 1 1 1 2 2 3 1 1/4 to 1 1/4 to 1 1/4 to 2 to 2 3 to 36 2 1 1 2 2 3 3 to 4 3 to 36 3 to 36 flat 2 to 2 3 to 3 3 to 3 to 5 2 4 5 flat flat 3 to 8 6 to 12 3 to 3 4 to 5 5 to 6 6 10 to 36 14 to 36 4 to 5 6 to 8 8 to 12 8 to 10 flat flat 6 to 10 10 to 18 14 to 24 12 to 18 12 to 36 20 to 36 26 to 36 20 to 36 flat flat flat flat Hot Tap and Branch Connections.doc Page 850 Revision / Save Date: 3/15/17
TABLE 2 Run Sizes TABLE 3 Run Sizes The following table applies to Class 6000 threadolet, Class 6000 sockolet, and XXS nipolet. Outlet Size Inches 1/4 3/8 3/4 1 1 1/4 1 2 1 3/4 1 1 1/4 to 1 1 2 2 1 3/4 3/4 1 1/4 to 2 1 1/4 to 2 1 1/4 to 2 2 to 2 2 to 2 2 3 1 2 to 6 3 to 10 3 to 10 3 to 3 3 to 3 4 3 to 36 1 1/4 to 1 8 to 36 12 to 36 12 to 36 4 to 8 4 to 5 5 flat 2 to 2 flat flat flat 10 to 36 6 to 8 6 3 to 8 flat 10 to 18 8 to 10 10 to 36 20 to 36 12 to 20 flat flat 24 to 36 flat The following table applies to schedule 160 and XXS weldolet. Outlet Size Inches 3/4 1 1 1/4 1 2 1 3/4 1 1 1/4 to 1 1 2 3/4 to 1 1 1/4 to 2 1 1/4 to 2 1/4 2 to 2 2 to 2 2 1 to 36 2 to 6 3 to 10 3 to 10 3 to 3 3 to 3 flat 8 to 36 12 to 36 12 to 36 4 to 8 4 to 5 flat flat flat 10 to 20 6 to 8 22 10 to 18 24 to 36 20 to 36 flat flat 1.7 Reinforcing Members (for use with Field Fabricated Branch Connections) For design considerations, reference Section 2.2. Preference shall be given to saddle type reinforcements over pad types, as the saddle type of members extend onto the branch pipe and more uniformly distributes the external loads Reinforcing member specifications; type, thickness and grade; shall be determined by a Design Engineer. These calculations must take into account the MAOP, diameter, existing measured wall thickness, grade (Yield Strength), and Class Location of the header pipe. The reinforcement thickness should be no more than 1.25 times the thickness of the header pipe. In general, the Hot Tap and Branch Connections.doc Page 851 Revision / Save Date: 3/15/17
selected grade of the reinforcement shall be equal or less than the header piping due to the fact that the reinforcing calculations do not use the extra strength obtained from using a grade higher than the header grade. Field fabricated branch connections that are 1/3 the header pipe size and larger should have a full encirclement type of reinforcement. A full encirclement member will provide better support and more even distribution of external forces. 2 Welded Branch Connections When welded branch connections are made to steel pipe in the form of a single connection or in a header or manifold as a series of connections, the design must be adequate to control the stress levels in the pipe within safe limits to ensure that the strength of the pipeline system is not reduced. The required reinforcement shall be calculated per ASME B31.8/B31.4 by hand or by using Pipeline Toolbox (Reinforcement of Welded Branch Connections). All cases involving hot tapping or construction of branch connections must be investigated by Design Engineering to insure adequate reinforcement. All pipe branch connections shall have reinforcement. Additional reinforcement is not required for servicetap fittings, pig signal type fittings or any other fitting in which the reinforcement is integral to the fitting. For all sizes, branch pipe wall thickness shall, at a minimum be extra strong. This will provide stiffness to the branch connection and associated appurtenances. Weep holes in reinforcing members shall be protected from water entrainment by a means other than welding, such as sealing with silicon or covering with Denso Protal two part epoxy. All welding shall be in accordance with Company welding procedures. 2.1 In-Service Welded Branch Connection (Hot Tap) The tapping of pipelines under pressure should only be performed by personnel who are qualified in the procedures and equipment used. (see MP-068 Tapping a Pipeline) The line to be tapped shall be accurately identified. If installing branch connections that are larger than of the header pipe size, additional consideration shall be given to the following pigging requirements of the header pipeline (see Section 1.2 of this standard). Design Engineering shall determine barring requirements based on anticipated operating conditions. external loading considerations (particularly during tapping process, if applicable) material availability Reducing line pressure for in-service welding is not required. A reduction in pressure may negatively affect the quality of the weldment by initiating a higher flow rate, causing the weld to cool too quickly, potentially resulting in hydrogen cracking. The pipe to be tapped should be free of bends within a distance of three (3) nominal pipe diameters or five (5) feet from the branch connection, whichever is less The pipe to be tapped shall be in sound condition. It shall be visually examined for external corrosion. The wall thickness shall be verified per MP-092 - Measure Pipe Thickness using Ultrasonic Thickness Gauge. Pipe having a measured thickness less than 0.188 inch, or pipe in questionable Hot Tap and Branch Connections.doc Page 852 Revision / Save Date: 3/15/17
condition, shall not be welded while in service unless approved by Design Engineering and/or the Weld Coordinator. The tap and branch connection should be positioned so that any reinforcement does not contact a joint weld. Connections may be positioned in either a horizontal or vertical plane as conditions require. Piping associated with the tap should be buried when located within the pipeline right-of-way. The branch nipple (including any pipe specifically purchased as a nipple ) used in the Hot Tap assembly, shall be pretested at a pressure 1.5 times the design pressure and as specified in the Design and Construction Standard 9.1 Strength Testing of Pipeline Facilities. The pretest shall occur before the nipple is fitted to the header. A strength test is not to be conducted with the nipple welded in place. After welding the branch connection (pipe nipple, or o let and pipe nipple) to the header pipe, and prior to installing any reinforcement or drilling through the pipe, the attached branch and valve will be subjected to a leak test. The assembly shall be bubble tested for leaks using air or nitrogen at a pressure of 50 PSIG (or the pressure in the header piping, if less than 50 PSIG) for a period of ten (10) minutes. A hot tap is not considered a tie-in weld. The welds shall be nondestructively examined as per the Design and Construction Standard 3.1 Welding and Inspection Requirements. Backfilling shall be done in a manner to provide a firm foundation for both the header and the branch to prevent horizontal and vertical movement. Additional support shall be installed under all side tap valves. Hot Tap and Branch Connections.doc Page 853 Revision / Save Date: 3/15/17
2.2 Special Considerations for Branch Connections REINFORCEMENT OF WELDED BRANCH CONNECTIONS: SPECIAL CONSIDERATIONS Design Stress of Header (% of SMYS) Ratio of Branch Diameter to Header Diameter (Nominal) 1/4 Or Less Greater Than 1/4 Through Greater Than 20% or Less G G F, G Greater Than 20% through 50% D, G G F, G Greater Than 50% C, D, B A, E A -Smoothly contoured, wrought steel tees of proven design are preferred. When tees cannot be used, the reinforcing member should extend around the circumference of the header. Pads, partial saddles or other types of localized reinforcement should not be used B -Smoothly contoured tees of proven design are preferred. When tees are not used, the reinforcing member should be of the complete encirclement type, but may be of the pad type, saddle type, or a welding outlet fitting C -The reinforcement member may be of the complete encirclement type, pad type, saddle type or welding outlet fitting type. The edges of reinforcement members should be tapered to the header thickness. It is recommended that legs of fillet welds joining the reinforcing members and header do not exceed the thickness of the header D - Reinforcement calculations are not normally made for openings 2 inches and smaller in diameter. However, care should be taken to provide suitable protection against vibrations and other external forces to which these small openings are frequently subjected E - The inside edges of the finished opening should, whenever possible, be rounded to a 1/8 inch radius. If the encircling member is thicker than the header and is welded to the header, the ends should be tapered down to the header thickness and continuous fillet welds should be made. F -When a reinforcement member is used, and the branch diameter is such that a localized type of reinforcement member would extend around more than half the circumference of the header, then a complete encirclement type of reinforcement member should be used, regardless of the design hoop stress; or a smoothly contoured wrought steel tee of proven design may be used G -The reinforcement may be of any type described within this standard Hot Tap and Branch Connections.doc Page 854 Revision / Save Date: 3/15/17
Version Control Field Name Author: Comments: Checked By: Department: Editor: Owner: Keywords: Status: Field Contents Brian Tucker Developed By: Pro-Tech Solutions, Inc. Spring, Texas Phone: (281) 320-2398 Sheila Miller Design Engineering Rich Wyman Ted Charletta Hot Tap, Branch Connection, Reinforcement, Saddle, Barred Tee, In Service Welding, Pad Approved Section: 03.04 Revision Record Revision Number Description of Revision Reviewer Initials Owner Initials Approval Date Original Issue BMT DRD 2/14/10 1. 2. 3. Section 2.1 Eliminated the following requirement: The tap and branch connection should be positioned so that no portion is within two (2) inches of the longitudinal seam of the parent pipe Updated hyperlinks. Removed the Hot Taps standard drawing link. Added pictures and descriptions for various olets and conventional run size tables in Section 1.6. Separated Section 1.4 into 1.4 and 1.5 to account for difference between line stop fittings and hottap split reinforcing tees. STM DRD 6/12/12 RAW TAC 12/12/2016 Hot Tap and Branch Connections.doc Page 855 Revision / Save Date: 3/15/17
Administrator Notes: Hot Tap and Branch Connections.doc Page 856 Revision / Save Date: 3/15/17