SECTION STEAM ENERGY DISTRIBUTION

Transcription

1 SECTION PART 1 GENERAL 1.1 SUMMARY A. Section includes: Pre-engineered, direct-buried, drainable, dryable, and testable piping system for steam energy utility piping systems. B. The work shall include all materials, equipment, and labor required for complete and properly functioning process piping systems. C. Drawings are intended to be schematic in nature in order to communicate the scope of work and show general arrangement of equipment and piping. Contractor shall make reasonable changes in arrangement and configuration of equipment and piping as directed by Engineer without additional cost to the Owner. D. Drawings and Specifications for process piping work are intended to be complementary in conveying the scope of work. Contractor shall complete work shown on one (1) Drawing regardless of whether it is shown on other Drawings or Specifications. Should a conflict be found, Contractor shall immediately contact Owner and Engineer. 1.2 REFERENCES A. The publications listed below form a part of this Specification to the extent referenced. The publications are referenced in the text by the basic designation only. B. Contractor shall comply with all such regulations and standards and shall protect and indemnify Owner and Engineer against any and all claims or liabilities arising from, or based upon, nonconformance with the regulations during normal service conditions. C. American Society of Mechanical Engineers (ASME): 1. ASME B31.1 Code for Pressure Piping Power Piping. D. ASTM International (ASTM): 1. ASTM A36/A36M Standard Specification for Carbon Structural Steel. 2. ASTM A53/A53M Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded, and Seamless. 3. ASTM A106/A106M Standard Specification for Seamless Carbon Steel Pipe For High-Temperature Service. 4. ASTM A167 Standard Specification for Stainless and Heat-Resisting Chromium- Nickel Steel Plate, Sheet, and Strip. 5. ASTM C591 Standard Specification for Unfaced Preformed Rigid Cellular Polyisocyanurate Thermal Insulation. E. American Welding Society (AWS): 1. AWS B2.1 Specification for Welding Procedure and Performance Qualification. 2. AWS D1.1 Structural Welding Code Steel. 1.3 SUBMITTALS A. Submit all items listed under each group simultaneously (except for items that can only be submitted during construction and upon completion of construction). 1. Pre-engineered direct-buried systems: a. Complete descriptions and drawings of system design and materials of construction, including component parts, assembly, carrier pipes, casing, anchors, pipe guides, pipe supports, expansion loops, manholes, vaults and building wall penetrations, end seals, gland seals, leak plates, and field installation instructions

2 b. A detailed design layout of the system showing the size, type, and location of each component and the design of anchors and valve vault wall penetrations. c. Manufacturer s written installation instructions. d. Manufacturer s quality assurance plan for fabrication, delivery, storage, installation, and testing of system. e. Certificate of Qualification from system manufacturer that the manufacturer s field representative regularly performs the specified duties of monitoring the installation of the system and is technically qualified and experienced in the installation of the system and is authorized by the supplier to make and sign the daily reports specified herein. f. Manufacturer s data sheets and thickness of carrier pipe insulation. g. Each system layout shall be computer analyzed by the piping system manufacturer to determine stresses and movements of the service pipe. The system design shall be in strict conformance with ASME B31.1 latest edition, and stamped by a registered Professional Engineer in the State of Illinois. Provide results of such analysis, including inputs and outputs of computerized software. h. All drawings and calculations shall have Professional Engineer's stamp. i. A proposed schedule of activities indicating when various items of work and tests shall be carried out and when quality control inspectors of the supplier are present at the job site. j. The daily written report from the manufacturer s representative at the job site during all stages of material delivery and construction. k. Upon completion of the work: 1) Certificate of Compliance signed by principal officers of the manufacturer and the Contractor certifying that the system has been installed in accordance with Contract requirements. 2) Operation and maintenance manual. 3) As-built layout of system including all final elevations (hard copies and AutoCAD on CD). B. Independent weld-testing firm for pre-engineered, direct-buried carrier piping: 1. Certificate of Qualification of testing firm. 2. Certificate of Acceptability of actual welds. C. Proposed test procedures and samples of test data sheets for each required test, 30 days prior to the test date. D. Test reports resulting from testing of installed systems, in booklet form showing all field tests performed to prove compliance with specified performance criteria. E. Radio-frequency identification tags (RFID): 1. Manufacturer s installation instructions. 2. Manufacturers cut sheet. 3. Plan for placement including locations and depths for each tag. 1.4 STORAGE AND HANDLING A. The Contractor is solely responsible for the protection of the equipment and material against damage from any source. Protect piping systems against entry of water and mud and all foreign substances by installing watertight protection on open ends at all times. Protect directburied system coatings from ultraviolet light (sunlight). B. All insulated piping systems exposed to water must be replaced with new systems. C. Place all damaged items with ones in first class, new operating condition or replace damaged items as determined and directed by the Owner s Representative, at no additional cost to the Owner. 1.5 JOB CONDITIONS

3 1.6 WARRANTY A. Phasing of demolition and construction shall be in accordance with the provisions as shown on the plans. B. Interruption of existing service: Any interruption of existing utility service shall be coordinated with and approved by the Owner prior to the interruption. A. Provide a five- (5) year warranty on pre-insulated pipe system including, field joints, insulation jacket, conduit, supports, gland seals, and eccentric connections. 1.7 DEFINITIONS A. Large bore piping: Piping detail routed on Drawings is generally 2 ½ and larger in diameter, unless indicated otherwise. B. Small bore piping: Piping not routed on Drawings is generally 2 and smaller in diameter. Contractor shall field-route small bore piping based upon requirements of Piping and Instrumentation Diagrams (PIDs), unless indicated otherwise. C. Density: Pounds per cubic foot (lb/ft 3 ). D. Thermal conductance: Heat flow rate through materials. 1. Pipe or cylinder: BTU per hour per linear foot (BTU/h- ft). E. Thermal conductivity (k): BTU per inch thickness, per hour, per square foot, per degree F temperature difference (Btu-in/hr-ft 2 - F). F. The terms pre-insulated pipe and pre-engineered pipe are used interchangeably throughout the Project Contract and Project Drawings. PART 2 PRODUCTS 2.1 PRE-ENGINEERED, FACTORY-FABRICATED, PIPING SYSTEMS A. Comply with the requirements of ASME B31.1. B. Piping system: Provide complete piping system, including carrier pipe, carrier pipe insulation with jackets and banding, air space, steel casing, fusion-bonded epoxy casing coatings, and accessories. C. Design pressure and temperature: All components of the system shall be suitable for carrier pipe pressures and temperatures as follows: 1. Medium-Pressure Steam (MPS) system: Rated for 325 psig at 450 F. 2. Medium-Pressure Condensate (MPC) system: Rated for 325 psig at 450 F. D. Medium-Pressure Steam (MPS) Carrier pipe: ASTM A106B, Grade B, seamless carbon steel. 1. Wall thickness: a. Pipe sizes 2 and below: Extra strong (XS). b. Pipe sizes 2 ½ through 18 : Standard weight (STD). c. Pipe sizes 20 through 24 : Extra strong (XS). 2. Piping joints shall not be allowed in factory-fabricated straight sections of preengineered, direct-buried systems. 3. Factory-fabricated, direct-buried piping sections that are a portion of an expansion loop or bend shall have all welded joints 100% radiograph inspected. E. Medium-Pressure Condensate (MPC) Carrier pipe: ASTM A106B, Grade B, seamless carbon steel. 1. Wall thickness: a. Pipe sizes 2 and below: Extra strong (XS). b. Pipe sizes 2 ½ through 18 : Schedule 80 c. Pipe sizes 20 through 24 : Extra strong (XS)

4 2. Piping joints shall not be allowed in factory-fabricated straight sections of preengineered, direct-buried systems. 3. Factory-fabricated, direct-buried piping sections that are a portion of an expansion loop or bend shall have all welded joints 100% radiograph inspected. F. Carrier pipe insulation: 1. Type: High temperature, flexible insulation blanket. 2. Insulation material: Silica aerogel reinforced with non-woven fiberglass batting. 3. Thickness: Maximum temperature rating: 1,200 F. 5. Thermal conductivity: 0.32 Btu-in/hr-ft^2- F at 400 F. 6. Density: 12.0 lbs per ft Insulation banding: Stainless steel bands and clips at least ½ wide, ASTM A167 (Type 304 stainless steel), maximum spacing 18. A minimum of two (2) bands is required for each 4-foot section of insulation. 8. Manufacturer: Thermaxx Jackets, Pyrogel XT, or equal. G. Outer conduit: 1. The steel conduit casing shall be smooth-wall, welded-steel conduit. a. Conduit size: 6 to 26. b. Conduit thickness: 10 gauge. 2. Changes in casing size, as required at oversized casing to allow for service pipe expansion, shall be accomplished by eccentric and/or concentric fittings and shall provide for continuous drainage. H. Pipe supports: 1. All pipes within the outer casing shall be supported at not more than 10-foot intervals. These supports shall be designed to allow for continuous airflow and drainage of the conduit in place. 2. Supports shall be designed to occupy not more than 10% of the annular air space. 3. Supports shall be arranged with insulation such that carrier piping is thermally isolated from outer conduit. 4. Protect surface of insulation at each support with 12 or longer pipe sleeve, fitted with traverse and, where required, rotational arresters. I. Outer conduit insulation and jacket: 1. Type: Spray-applied polyurethane or polyisocyanurate foam, in accordance with ASTM C Thickness: 1-1/2 minimum, 3 maximum. 3. Thermal conductivity: to Btu-in/hr-ft2- F at 75 F. 4. Density: Nominal 2.0 lbs per ft 3 for straight lengths and fittings. 5. Manufacturer shall conduct visual inspection and/or infrared inspection prior to installation of jacketing, but not more than 24 hours before installation of insulation foam to confirm no presence of voids. 6. Jacket: a. Filament-wound fiberglass (FRP) (175 mil minimum) or heavyweight seamless, high-density polyethylene (175 mil minimum). b. Apply directly onto the foam insulation. c. All straight piping segments and fittings shall have jacket factory-applied. d. All straight joint insulation kits for HDPE jacket shall be EN 489 pressure testable. Rhino-joint by Rovanco or equivalent. J. End seal and gland seal with vents and drains: 1. Construction: ASTM A36 structural steel, minimum thickness ½ for all casings. 2. Provide ¾ drain at the bottom and vent at the top. 3. Seals shall provide a water- and air-tight seal within the insulation spaced between the conduit and outer jacket as well as between conduit and the carrier pipe. Seals shall not extend more than 4 inside of the vault walls. K. Anchor plates: 1. Construction: ASTM A36 structural steel, welded to carrier pipe and steel conduit. 2. Thickness: ½ minimum

5 3. Provide passages for air flow and water drainage through the annular air space in the system. 4. Apply jacket coating to all anchor plates. Match coating system with same coating material as the casing. Locate as shown on Drawings. Anchors shall have 4 feet of 10-gauge 20-mil fusion-bonded epoxy casing extended on either side of anchor for heat dispersion with the HDPE system. Anchors shall have outer conduit. 5. Extend coating from anchor plate to a minimum of 4 feet on either side for heat dissipation. Coating thickness shall be a minimum thickness of 175 mil. 6. Coat anchor itself shall with FRP coating at a minimum thickness of 175 mils. L. Field connection of outer conduit sections: 1. Field connection of outer conduit sections shall be in accordance with the outer conduit requirements specified herein. 2. Contractor shall weld casing sections, apply coating to all surfaces with system manufacturer s coating field repair compound, and cover with manufacturer s recommended shrink sleeve or fiberglass coating. 3. Contractor shall use manufacturer recommended field connections and complete in strict accordance with manufacturer s instructions and recommendations to comply with all pre-engineered piping system warranty provisions. (Rovanco Rhino-joint or equivalent.) M. Valve vault wall, floor, and ceiling penetrations: Refer to Section Common Work Results for Steam Energy Systems (Non-Buried). N. Basis of design manufacturer: 1. Rovanco Piping Systems, Inc. Insul-800 Elite system. O. Other acceptable manufacturers: 1. Perma-Pipe, Inc. Multi-Therm 750 system. 2. Thermacor Process, Inc., Duo-Therm 505 system. 2.2 UTILITY LOCATION DEVICE: A. Type: Radio-frequency identification (RFID); magnetic locating capable. B. RFID system shall be capable of storing notes and be readable/writeable. C. Provide with stainless steel backing plate. D. Utilize class 1, generation 2, passive RFID tag. E. Manufacturer: InfraMarker Model 483, or equal. PART 3 EXECUTION 3.1 GENERAL A. Connecting to existing work: Connect new work to existing work in a neat and workmanlike manner. Where an existing structure must be cut or existing utilities interfere, such obstruction shall be bypassed, removed, replaced or relocated, patched, and repaired. Work disturbed or damaged shall be replaced to its prior condition. Piping connections shall be made only in manholes. B. Grading: As shown on Drawings. 3.2 DEMOLITION A. Perform work in accordance with requirements for phasing. B. Completely remove all pipe, valves, fittings, insulation, and hangers including the connection to the structure and any fastenings and as shown on the Drawings

6 C. Seal all openings in valve vaults after removal of piping through wall penetrations. D. All material and equipment removed shall become the property of the Contractor and shall be removed. 3.3 PIPING JOINTS AND FITTINGS A. Welded joints: 1. Branch connections shall be made with either welding tees or welding outlet fittings. Welding outlet fittings shall be forged, integrally reinforced to provide 100% pipe strength, beveled for full penetration welding, and funneled at inlet for full fluid flow. 2. Clean pipe and fittings before welding and installation in system. B. Threaded joints: 1. Pipe threads shall be cut to give proper engagement in threaded fittings. Threaded pipe shall have clean-cut threads; dull or damaged pipe dies shall not be used. 2. Clean pipe and fittings before installation and ream pipe after cutting threads. Joints shall be made with oil and graphite pipe joint compound applied to male threads only. 3.4 CLEANING OF PIPING 3.5 WELDING A. Clean pipe and fittings inside and outside before and after assembly. Remove all dirt, scale, and other foreign matter from inside the piping by use of a pipe swab or pipe pig before connecting pipe sections, valves, equipment, or fittings. A. The Contractor is entirely responsible for the quality of the welding and shall: 1. Conduct tests of the welding procedures used by its organization, determine the suitability of the procedures used, determine that the welds made will meet the required tests, and also determine that the welding operators have the ability to make sound welds under standard conditions. 2. Comply with ASME B31.1 and AWS B Perform all welding operations required for construction and installation. B. Qualification of welders: Rules of procedure for qualification of all welders and general requirements for fusion welding shall conform with the applicable portions of ASME B31.1 and AWS B2.1, and also as outlined below. C. Examining welder: Examine each welder at job site, in the presence of the Owner s Representative, to determine the ability of the welder to meet the qualifications required. D. Beveling: Field bevels and shop bevels shall be done by mechanical means. E. Defective welds: Replace and re-inspect defective welds. Repairing defective welds by adding weld material over the defect or by peening will not be permitted. Welders responsible for defective welds must be requalified. F. Electrodes: Electrodes shall be stored in a dry, heated area, and be kept free of moisture and dampness during fabrication operations. Discard electrodes that have lost part of their coating. G. Radiographic testing for piping to be inserted into the jacked casing pipe under roads: An approved independent testing firm regularly engaged in radiographic testing shall perform radiographic examination of 100% of field welds of the carrier piping, which will be inserted as a pre-insulated pipe system into the jacked casing pipe, in accordance with ASME B31.1. Furnish a set of films showing each weld inspected, a reading report evaluating the quality of each weld, and a location plan showing the physical location where each weld is located in the completed project. Prior to insertion of the piping system into jacked casing pipe, all radiographs shall be reviewed, interpreted, and meet maximum defect requirements by an ASNT Certified Level III radiographer, employed by the testing firm, who shall sign the reading report. The Owner reserves the right to review all inspection records, and if any welds

7 inspected are found unacceptable, they shall be removed, re-welded, and radiographically reexamined at no cost to Owner. H. Non-destructive examination of piping welds: 1. Owner (or Special Inspector) may test up to 10% of the welded piping joints to be examined using radiographic testing. If defective welds are discovered, the Owner s Representative or Special Inspector may require examination of all pipe joint welds at Contractor s expense. 2. Owner may choose to employ magnetic particle testing, dye penetrant, or other testing methods. 3. Owner will employ an independent testing firm regularly engaged in radiographic testing to perform the radiographic examination of pipe joint welds. 4. If independent testing agency finds any failures, Contractor shall correct deficiencies found to the satisfaction of the testing firm. Testing firm shall complete radiographic testing of 100% of the welds at Contractor s expense. a. Comply with ASME B31.1. Furnish a set of films showing each weld inspected, a reading report evaluating the quality of each weld, and a location plan showing the physical location where each weld is to be found in the completed Project. b. Owner reserves the right to review all inspection records of supplemental testing. All radiographs will be reviewed and interpreted by an ASNT Certified Level III radiographer, employed by the testing firm, who will sign the reading report. 5. Owner may perform destructive tests for compliance with applicable codes. If destructive tests indicate that welds meet requirements, Owner will pay for costs of repairs. If tests indicated non-compliance, cost of replacement, repairs, and retesting shall be paid by Contractor. 3.6 PIPE SUPPORT INSTALLATION (IN TRENCHES, TUNNELS, AND VAULTS) A. Coordinate support locations with structure prior to erection of piping. Arrangement of supports shall facilitate operating, servicing and removal of valves, strainers, and piping specialties. 3.7 PAINTING EXPOSED STEEL SURFACES IN VAULTS A. Provide surface cleaning and preparation and apply prime coat of rust resistant metal primer. 3.8 DIRECT-BURIED SYSTEM INSTALLATION A. All work shall be in strict accordance with the requirements specified herein and with the printed instructions of the manufacturer. Printed instructions must be available at the site prior to delivery of system components. Any changes required to the design and layout of the system due to site conditions must be approved in writing by the Engineer and Owner. B. Excavation, trenching, and backfilling: Perform all excavation, trenching, and backfilling as required by the system manufacturer s design and as specified in Section Earth Moving. Beach sand or any sand with large amounts of chlorides is not permitted. Place system on a 12 thick sand bed and backfill on all sides with 6 thick sand as measured from outside the casing. Foundation for system must be firm and stable. Foundation and backfill must be free from rocks or substances that could damage the system coating. Concrete anchor must be installed in undisturbed earth. Backfilling must not commence until elevations have been surveyed and accepted and system has been satisfactorily pressure tested including hydrostatic testing of carrier pipes and air testing of casings. C. Representative of system manufacturer: This shall be a person who regularly performs the duties listed below. The person shall be certified in writing by the system manufacturer, be technically qualified and experienced in the installation of the system, and be authorized by the manufacturer to instruct Contractor regarding installation of pre-insulated piping system. The representative shall be on site for five (5) days throughout the Project and provide the following as defined below: 1. Oversight of the first field joint installation of the pre-insulated piping system. Manufacturer s representative shall instruct Contractor on the correct field joint

8 installation procedure, inspect the first field joint to be independently installed by the Contractor, and instruct Contractor on proper field joint testing procedure. 2. Oversight of the installation of the first oversized corner and eccentric reduction cone of pre-insulated piping system. Manufacturer s representative shall instruct Contractor on the correct installation procedures, and shall inspect the first field joint to be independently installed by the Contractor. 3. Manufacturer s representative shall perform a walkthrough inspection of all directburied pre-insulated pipe immediately prior to Contractor backfilling the excavated area. 4. The fourth (4 th ) and fifth (5 th ) days shall be built in as Project contingency days and may be requested by the Owner or Engineer. D. Protect casing coating from damage during rigging, storage, and installation. Protect casing and carrier pipe ends from water intrusion during rigging and installation. Protect casing coatings from ultraviolet light (sunlight). E. Defective material: The manufacturer s representative shall take prompt action to return to the factory all damaged or defective material and shall order prompt replacement of such material. F. Slope of carrier pipes: Maintain constant slope as shown. Prior to backfilling over the top of the casing, but after removal of temporary supports, Contractor shall measure and record elevations of top of casing in the trench. Elevations shall be taken at every field joint, 1/3 points along each pipe section, and at tops of elbows. G. Cleaning of piping: Remove all dirt, scale, and other foreign matter from inside the piping by use of a pipe swab or pipe pig before connecting pipe sections, valves, or fittings. H. Wet insulation: Sections of system that have been fully or partially submerged in water must be replaced. Moisture content of insulation during installation shall not exceed 5% by weight. I. Vents and drains on ends of systems: At each casing termination (gland seal) in vaults. 3.9 UTILITY LOCATION DEVICE INSTALLATION 3.10 TESTS A. Install RFID tags in strict accordance with manufacturer s instructions and recommendations. B. Install RFID Tags not more than 3 below finished grade, directly above new piping centerline where shown on Drawings, at all elbows and fittings, and every 50 feet along straight sections of piping. A. Demonstrate leak-tightness of all piping systems by performing hydrostatic and operational tests. All labor, material, and test instruments must be furnished by the Contractor. B. Conduct hydrostatic pressure test direct-buried systems in accordance with ASME B31.1 and this section. Tests shall be completed for the carrier piping. C. Holiday testing of outer conduit coatings: Test entire surface of outer conduit for faults in coating after installation in trench prior to backfilling. Use test method and voltage recommended by coating manufacturer. Repair any holidays found and retest. System shall not be backfilled until all holidays are eliminated. D. Radiographic testing: In lieu of hydrostatic pressure testing of the carrier piping to be inserted into jacked casing under roads, Contractor shall provide independent radiographic inspection of 100% of the carrier pipe welds. Refer to Article, WELDING, in Part 3 of this Specification. E. Hydrostatic and operational tests of carrier piping: Steam and condensate carrier piping shall be tested hydrostatically before insulation is applied at field joints and shall be proved tight at a pressure 1 ½ times distribution supply pressure for a period not less than two (2) hours with no pressure decay

9 1. Test piping located in concrete trenches prior to installing trench covers. Test directburied systems prior to backfilling. 2. Remove or isolate any elements of the system such as expansion joints, which are not designed for the test pressure. 3. Prior to acceptance of installation, Contractor shall subject system to operating tests to demonstrate satisfactory functional and operating efficiency. These operating tests shall cover a period of not less than six (6) hours for each portion of system tested. Conduct tests at times as the Owner may direct. 4. Provide calibrated instruments, equipment, facilities, and labor, at no additional cost to Owner. Test gauge shall read in increments not exceeding 0.1 psig. 5. Repeat tests when failures occur. 6. After completion of satisfactory test, replace all elements that have been removed prior to testing. F. The space between the carrier pipe and the conduit pipe of the pre-insulated piping system shall be air tested at 100% of all field joints to be pushed into casing under road, and at a minimum of once every 10 joints in all other portions of piping. This space shall be pressure tested to 15 psig for not less than 1 hour with no pressure decay prior to the subsequent section installation. Contractor shall use a temporary casing end seal provided by the manufacturer to close both ends of the pipe containing the field joint to be pressure tested. G. 100% of field joint jacket seal shall be pressure tested by the Contractor. The seal shall have no holes drilled by the Contractor to perform the test. The jacket field joint shall be tested at 5 psig for not less than 10 minutes with no pressure decay. H. Deficiencies discovered shall be corrected at the Contractor's expense, to satisfaction of Owner s Representative. Major deficiencies or failure to correct deficiencies to the satisfaction of the Owner s Representative may be considered cause for rejecting the entire installation. END OF SECTION

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