23_11_23.00_10_GAS_PIPING_SYSTEMS.pdf

SECTION 23 11 23.00 10

GAS PIPING SYSTEMS

PART 1 GENERAL

1.1 REFERENCES

1.1.1 The publications listed below form a part of this specification to the extent referenced. The publications are referred to in the text by the basic designation only. Unless other wise noted, the latest published version and/or revision shall be used.

1.1.1.1 AMERICAN GAS ASSOCIATION (AGA)

a. AGA XR0104 AGA Plastic Pipe Manual for Gas Service

1.1.1.2 AMERICAN PETROLEUM INSTITUTE (API)

a. API Spec 6D Specification for Pipeline Valves

1.1.1.3 ASME INTERNATIONAL (ASME)

a. ASME B1.20.1 Pipe Threads, General Purpose (Inch)

b. ASME B16.11 Forged Fittings, Socket-Welding and Threaded

c. ASME B16.21 Nonmetallic Flat Gaskets for Pipe Flanges

d. ASME B16.3 Malleable Iron Threaded Fittings, Classes 150 and 300

e. ASME B16.33 Manually Operated Metallic Gas Valves for Use in Gas Piping Systems Up to 125 psi, Sizes NPS 1/2 - NPS 2

f. ASME B16.5 Standard for Pipe Flanges and Flanged Fittings: NPS 1/2 Through NPS 24

g. ASME B16.9 Standard for Factory-Made Wrought Steel Buttwelding Fittings

h. ASME B31.1 Power Piping

i. ASME B31.2 Fuel Gas Piping

j. ASME B36.10M Standard for Welded and Seamless Wrought Steel Pipe

k. ASME BPVC SEC IX Boiler and Pressure Vessel Code; Section IX, Welding and Brazing Qualifications

1.1.1.4 ASTM INTERNATIONAL (ASTM)

a. ASTM A 513 Standard Specification for Electric-Resistance-Welded Carbon and Alloy Steel Mechanical Tubing

b. ASTM B 88 Standard Specification for Seamless Copper Water Tube

c. ASTM B 88M Standard Specification for Seamless Copper Water Tube (Metric)

1.1.1.5 CSA AMERICA, INC. (CSA/AM)

a. CSA/AM Z21.24 Connectors for Gas Appliances

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b. CSA/AM Z21.69 Connectors for Movable Gas Appliances

1.1.1.6 MANUFACTURERS STANDARDIZATION SOCIETY OF THE VALVE AND FITTINGS

INDUSTRY (MSS)

a. MSS SP-25 Standard Marking System for Valves, Fittings, Flanges and Unions

b. MSS SP-58 Standard for Pipe Hangers and Supports - Materials, Design and Manufacture

c. MSS SP-69 Standard for Pipe Hangers and Supports - Selection and Application

1.1.1.7 NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)

a. NFPA 54 National Fuel Gas Code

b. NFPA 70 National Electrical Code

1.1.1.8 UNDERWRITERS LABORATORIES (UL)

a. UL Gas&Oil Dir Flammable and Combustible Liquids and Gases Equipment Directory

1.2 SUBMITTALS

1.2.1 Government approval may be required on any of the following items. Items requiring submittals will be listed on the AF Form 66. Provide copies of all submittals per the requirements in Section 01 33 00, Submittal Procedures, or as listed on the AF Form 66.

1.2.1.1 SD-02 Shop Drawings

a. Gas Piping System

(1) Drawings showing location, size and all branches of pipeline; location of all required shutoff valves; and instructions necessary for the installation of connectors and supports.

1.2.1.2 SD-03 Product Data

a. Welding

(1) Qualified procedures and a list of names and identification symbols of qualified welders and welding operators.

b. Gas Piping System

(1) Catalog data and installation instructions for pipe, valves, and all related system components

1.2.1.3 SD-06 Test Reports

a. Testing

b. Pressure Tests

c. Test With Gas

Test reports in booklet form tabulating test and measurements performed. The reports shall be

23 11 23.00 10-2 02/06/12 dated after award of this contract, shall state the Contractor's name and address, shall name the project and location, and shall list the specific requirements which are being certified.

1.3 GENERAL REQUIREMENTS

1.3.1 Welding

1.3.1.1 Piping shall be welded in accordance with qualified procedures using performance qualified welders and welding operators. Procedures and welders shall be qualified in accordance with ASME BPVC SEC IX. Welding procedures qualified by others, and welders and welding operators qualified by another employer may be accepted as permitted by ASME B31.1. The Contracting Officer shall be notified at least 24 hours in advance of tests and the tests shall be performed at the work site if practicable. The Contracting Officer shall be furnished with a copy of qualified procedures and a list of names and identification symbols of qualified welders and welding operators. The welder or welding operator shall apply his assigned symbol near each weld he makes as a permanent record. Structural members shall be welded in accordance with Section 05 05 23 Welding, Structural.

1.3.2 Standard Products

1.3.2.1 Materials and equipment shall be the standard products of a manufacturer regularly engaged in the manufacture of the products and shall essentially duplicate items that have been in satisfactory use for at least 2 years prior to bid opening. Asbestos or products containing asbestos shall not be used. Manufacturer's descriptive data and installation instructions shall be submitted for approval for compression-type mechanical joints used in joining dissimilar materials and for insulating joints. Valves, flanges and fittings shall be marked in accordance with MSS SP-25.

1.3.3 Verification of Dimensions

1.3.3.1 The Contractor shall become familiar with all details of the work, verify all dimensions in the field, and shall advise the Contracting Officer of any discrepancy before performing the work.

PART 2 PRODUCTS

2.1 PIPE AND FITTINGS

2.1.1 Steel Pipe, Joints, and Fittings

2.1.1.1 Steel pipe shall conform to ASME B36.10M. Malleable-iron threaded fittings shall conform to ASME B16.3. Steel pipe flanges and flanged fittings including bolts, nuts, and bolt pattern shall be in accordance with ASME B16.5. Wrought steel butt welding fittings shall conform to ASME B16.9. Socket welding and threaded forged steel fittings shall conform to ASME B16.11.

2.1.2 Steel Tubing, Joints and Fittings

2.1.2.1 Steel tubing shall conform to ASTM A 513. Tubing joints shall be made up with gas tubing fittings recommended by the tubing manufacturer.

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2.1.3 Sealants for Steel Pipe Threaded Joints

2.1.3.1 Joint sealing compound shall be listed in UL Gas & Oil Dir, Class 20 or less.

Tetrafluoroethylene tape shall conform to UL Gas & Oil Dir.

2.1.4 Identification

2.1.4.1 Pipe flow markings and metal tags shall be provided as required.

2.1.5 Flange Gaskets

2.1.5.1 Gaskets shall be compressed material in accordance with ASME B16.21, 1/16 inch thickness, full face or self-centering flat ring type. The gaskets shall contain aramid fibers bonded with styrene butadiene rubber (SBR) or nitrile butadiene rubber (NBR) suitable for a maximum 600 degree F service. NBR binder shall be used for hydrocarbon service.

2.1.6 Pipe Threads

2.1.6.1 Pipe threads shall conform to ASME B1.20.1.

2.1.7 Escutcheons

2.1.7.1 Escutcheons shall be chromium-plated steel or chromium-plated brass, either one piece or split pattern, held in place by internal spring tension or set screw.

2.1.8 Insulating Pipe Joints

2.1.8.1 Insulating Joint Material

a. Insulating joint material shall be provided between flanged or threaded metallic pipe systems to control galvanic or electrical action.

2.1.8.2 Threaded Pipe Joints

a. Joints for threaded pipe shall be steel body nut type dielectric unions with insulating gaskets.

2.1.8.3 Flanged Pipe Joints

a. Joints for flanged pipe shall consist of full face sandwich-type flange insulating gasket of the dielectric type, insulating sleeves for flange bolts, and insulating washers for flange nuts.

2.1.9 Flexible Connectors

2.1.9.1 Flexible connectors for connecting gas utilization equipment to building gas piping shall conform to CSA/AM Z21.24. Flexible connectors for movable food service equipment shall conform to CSA/AM Z21.69.

2.2 VALVES

Valves shall be suitable for shutoff or isolation service and shall conform to the following:

2.2.1 Valves 2 Inches and Smaller

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2.2.1.1 Valves 2 inches and smaller shall conform to ASME B16.33 and shall be of materials and manufacture compatible with system materials used.

2.2.2 Valves 2-1/2 Inches and Larger

2.2.2.1 Valves 2-1/2 inches and larger shall be carbon steel conforming to API Spec 6D, Class 150.

2.3 PIPE HANGERS AND SUPPORTS

2.3.1 Pipe hangers and supports shall conform to MSS SP-58 and MSS SP-69.

PART 3 EXECUTION

3.1 EXCAVATION AND BACKFILLING

3.1.1 Earthwork shall be as specified in Section 31 00 00 Earthwork.

3.2 GAS PIPING SYSTEM

Gas piping system shall be from the point of connection to the existing gas piping to the connections to each gas utilization device.

3.2.1 Protection of Materials and Components

3.2.1.1 Pipe and tube openings shall be closed with caps or plugs during installation. Equipment shall be protected from dirt, water, and chemical or mechanical damage. At the completion of all work, the entire system shall be thoroughly cleaned.

3.2.2 Workmanship and Defects

3.2.2.1 Piping, tubing and fittings shall be clear and free of cutting burrs and defects in structure or threading and shall be thoroughly brushed and chip-and scale-blown. Defects in piping, tubing or fittings shall not be repaired. When defective piping, tubing, or fittings are located in a system, the defective material shall be replaced.

3.3 PROTECTIVE COVERING

3.3.1 Aboveground Metallic Piping Systems

3.3.1.1 Ferrous Surfaces

a. Shop primed surfaces shall be touched up with ferrous metal primer. Surfaces that have not been shop primed shall be solvent cleaned. Surfaces that contain loose rust, loose mill scale and other foreign substances shall be mechanically cleaned by power wire brushing or commercial sand blasted conforming to SSPC SP 6 and primed with ferrous metal primer or vinyl type wash coat. Primed surface shall be finished with two coats of exterior oil paint or vinyl paint.

3.3.1.2 Nonferrous Surfaces

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a. Except for aluminum alloy pipe, nonferrous surfaces shall not be painted. Surfaces of aluminum alloy pipe and fittings shall be painted to protect against external corrosion where they contact masonry, plaster, insulation, or are subject to repeated wettings by such liquids as water, detergents or sewage. The surfaces shall be solvent-cleaned and treated with vinyl type wash coat. A first coat of aluminum paint and a second coat of alkyd gloss enamel or silicone alkyd copolymer enamel shall be applied.

3.4 INSTALLATION

Installation of the gas system shall be in conformance with the manufacturer's recommendations and applicable provisions of NFPA 54, AGA XR0104, and as indicated. Pipe cutting shall be done without damage to the pipe. Unless otherwise authorized, cutting shall be done by an approved type of mechanical cutter. Wheel cutters shall be used where practicable. On steel pipe 6 inches and larger, an approved gas cutting and beveling machine may be used. Cutting of thermoplastic and fiberglass pipe shall be in accordance with AGA XR0104.

3.4.1 Metallic Piping Installation

3.4.1.1 Underground piping shall not be metallic. Changes in direction of above ground metallic piping shall be made with fittings only; mitering or notching pipe to form elbows and tees or other similar type construction will not be permitted. Branch connection may be made with either tees or forged branch outlet fittings. Branch outlet fittings shall be forged, flared for improvement of flow where attached to the run, and reinforced against external strains.

Aluminum alloy pipe shall not be used in exterior locations.

3.4.2 Metallic Tubing Installation

3.4.2.1 Metallic tubing shall be installed using gas tubing fittings approved by the tubing manufacturer.

Branch connections shall be made with tees. All tubing end preparation shall be made with tools designed for the purpose. Aluminum alloy tubing shall not be used in exterior locations or underground.

3.4.3 Thermoplastic and Fiberglass Piping, Tubing, and Fittings

3.4.3.1 Thermoplastic and fiberglass piping, tubing, and fittings shall be installed outside and underground only. Piping shall be buried a minimum of 18 inches below grade. The piping shall be installed to avoid excessive stresses due to thermal contraction. Thermoplastic and fiberglass piping shall only be allowed as indicated.

3.4.4 Concealed Piping in Buildings

When installing piping which is to be concealed, unions, tubing fittings, running threads, right-and left-hand couplings, bushings, and swing joints made by combinations of fittings shall not be used.

3.4.4.1 Piping in Partitions

a. Concealed piping shall be located in hollow rather than solid partitions. Tubing passing through walls or partitions shall be protected against physical damage.

3.4.4.2 Piping in Floors

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a. Piping in solid floors except where embedment in concrete is indicated shall be laid in channels suitably covered to permit access to the piping with minimum damage to the building.

3.4.5 Aboveground Piping

3.4.5.1 Aboveground piping shall be run as straight as practicable along the alignment indicated and with a minimum of joints. Piping shall be separately supported. Exposed horizontal piping shall not be installed farther than 6 inches from nearest parallel wall in laundry areas where clothes hanging could be attempted.

3.4.6 Final Gas Connections

3.4.6.1 Unless otherwise specified, final connections shall be made with rigid metallic pipe and fittings. Final connections to kitchen ranges shall be made using flexible connectors not less than 40 inches long. Flexible connectors may be used for final connections to residential dryers. In addition to cautions listed in instructions required by ANSI standards for flexible connectors, insure that flexible connectors do not pass through equipment cabinet. Provide accessible gas shutoff valve and coupling for each gas equipment item.

3.4.7 Seismic Requirements

3.4.7.1 Piping and attached valves shall be supported and braced to resist seismic loads as specified in UFC 3-310-04 Seismic Design for Buildings and Sections 13 48 00 Seismic Protection for Miscellaneous Equipment and 13 48 00.00 10 Seismic Protection for Mechanical Equipment.

3.5 PIPE JOINTS

Pipe joints shall be designed and installed to effectively sustain the longitudinal pull-out forces caused by contraction of the piping or superimposed loads.

3.5.1 Threaded Metallic Joints

3.5.1.1 Threaded joints in metallic pipe shall have tapered threads evenly cut and shall be made with UL approved graphite joint sealing compound for gas service or tetrafluoroethylene tape applied to the male threads only. Threaded joints up to 1-1/2 inches in diameter may be made with approved tetrafluoroethylene tape. Threaded joints up to 2 inches in diameter may be made with approved joint sealing compound. After cutting and before threading, pipe shall be reamed and burrs shall be removed. Caulking of threaded joints to stop or prevent leaks shall not be permitted.

3.5.2 Welded Metallic Joints

3.5.2.1 Beveling, alignment, heat treatment, and inspection of welds shall conform to ASME B31.2.

Weld defects shall be removed and repairs made to the weld, or the weld joints shall be entirely removed and rewelded. After filler metal has been removed from its original package, it shall be protected or stored so that its characteristics or welding properties are not affected adversely.

Electrodes that have been wetted or have lost any of their coating shall not be used.

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3.6 PIPE SLEEVES

3.6.1 Pipes passing through concrete or masonry walls or concrete floors or roofs shall be provided with pipe sleeves fitted into place at the time of construction. Sleeves shall not be installed in structural members except where indicated or approved. All rectangular and square openings shall be as detailed. Each sleeve shall extend through its respective wall, floor or roof, and shall be cut flush with each surface, except in mechanical room floors not located on grade where clamping flanges or riser pipe clamps are used. Sleeves in mechanical room floors above grade shall extend at least 4 inches above finish floor. Unless otherwise indicated, sleeves shall be large enough to provide a minimum clearance of 1/4 inch all around the pipe. Sleeves in bearing walls, waterproofing membrane floors, and wet areas shall be steel pipe. Sleeves in nonbearing walls, floors, or ceilings may be steel pipe, galvanized sheet metal with lock-type longitudinal seam, or moisture-resistant fiber or plastic. For penetrations of fire walls, fire partitions and floors which are not on grade, the annular space between the pipe and sleeve shall be sealed with firestopping material and sealant that meet the requirement of Section 07 84 00 Firestopping.

3.7 PIPES PENETRATING WATERPROOFING MEMBRANES

3.7.1 Pipes penetrating waterproofing membranes shall be installed as specified in Section 22 00 00 Plumbing, General Purpose.

3.8 FIRE SEAL

3.8.1 Penetrations of fire rated partitions, walls and floors shall be in accordance with Section 07 84 00 Firestopping.

3.9 ESCUTCHEONS

3.9.1 Escutcheons shall be provided for all finished surfaces where gas piping passes through floors, walls, or ceilings except in boiler, utility, or equipment rooms.

3.10 SPECIAL REQUIREMENTS

3.10.1 Drips, grading of the lines, freeze protection, and branch outlet locations shall be as shown and shall conform to the requirements of NFPA 54.

3.11 BUILDING STRUCTURE

3.11.1 Building structure shall not be weakened by the installation of any gas piping. Beams or joists shall not be cut or notched. Piping supports shall not be attached to metal decking. Supports shall not be attached to the underside of concrete filled floors or concrete roof decks unless approved by the Contracting Officer.

3.12 PIPING SYSTEM SUPPORTS

3.12.1 Gas piping systems in buildings shall be supported with pipe hooks, metal pipe straps, bands or hangers suitable for the size of piping or tubing. Gas piping system shall not be supported by other piping. Spacing of supports in gas piping and tubing installations shall conform to the requirements of NFPA 54. The selection and application of supports in gas piping and tubing

23 11 23.00 10-8 02/06/12 installations shall conform to the requirements of MSS SP-69. In the support of multiple pipe runs on a common base member, a clip or clamp shall be used where each pipe crosses the base support member. Spacing of the base support members shall not exceed the hanger and support spacing required for any of the individual pipes in the multiple pipe run. The clips or clamps shall be rigidly connected to the common base member. A clearance of 1/8 inch shall be provided between the pipe and clip or clamp for all piping which may be subjected to thermal expansion.

3.13 ELECTRICAL BONDING AND GROUNDING

3.13.1 The gas piping system within the building shall be electrically continuous and bonded to a grounding electrode as required by NFPA 70. Conventional flange joints allow sufficient current flow to satisfy this requirement.

3.14 SHUTOFF VALVE

3.14.1 Main gas shutoff valve controlling the gas piping system shall be easily accessible for operation and shall be installed as indicated, protected from physical damage, and marked with a metal tag to clearly identify the piping system controlled.

3.15 TESTING

Before any section of a gas piping system is put into service, it shall be carefully tested to assure that it is gastight. Prior to testing, the system shall be blown out, cleaned and cleared of all foreign material. Each joint shall be tested by means of an approved gas detector, soap and water, or an equivalent nonflammable solution. Testing shall be completed before any work is covered, enclosed, or concealed. All testing of piping systems shall be done with due regard for the safety of employees and the public during the test. Bulkheads, anchorage and bracing suitably designed to resist test pressures shall be installed if necessary. Oxygen shall not be used as a testing medium.

3.15.1 Pressure Tests

3.15.1.1 Before appliances are connected, piping systems shall be filled with air or an inert gas and shall withstand a minimum pressure of 3 pounds gauge for a period of not less than 10 minutes as specified in NFPA 54 without showing any drop in pressure. Oxygen shall not be used.

Pressure shall be measured with a mercury manometer, slope gauge, or an equivalent device so calibrated as to be read in increments of not greater than 0.1 pound. The source of pressure shall be isolated before the pressure tests are made.

3.15.2 Test With Gas

3.15.2.1 Before turning gas under pressure into any piping, all openings from which gas can escape shall be closed. Immediately after turning on the gas, the piping system shall be checked for leakage by using a laboratory-certified gas meter, an appliance orifice, a manometer, or equivalent device. All testing shall conform to the requirements of NFPA 54. If leakage is recorded, the gas supply shall be shut off, the leak shall be repaired, and the tests repeated until all leaks have been stopped.

3.15.3 Purging

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3.15.3.1 After testing is completed, and before connecting any appliances, all gas piping shall be fully purged. LPG piping tested using fuel gas with appliances connected does not require purging.

Piping shall not be purged into the combustion chamber of an appliance. The open end of piping systems being purged shall not discharge into confined spaces or areas where there are ignition sources unless the safety precautions recommended in NFPA 54 are followed.

3.15.4 Labor, Materials and Equipment

3.15.4.1 All labor, materials and equipment necessary for conducting the testing and purging shall be furnished by the Contractor.

3.16 PIPE COLOR CODE MARKING

3.16.1 Color code marking of piping shall be as specified in Section 09 90 00 Paints and Coatings.

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