The pipe shall be separated from the casing by insulating spacers and sealed at the ends with casing bushings. Trench shall be excavated below pipe on blocks to produce uniform grade will not be permitted.
The pipe shall be clean inside before it is lowered into the trench and shall be kept free of water, soil, and other foreign matter that might damage or obstruct the operation of the valves, regulators, meters, or other equipment.
When work is not in progress, open ends of pipe or fittings shall be securely closed by expandable plugs or other suitable means. Minor changes in line or gradient of pipe that can be accomplished through the natural flexibility of the pipe material without producing permanent deformation and without overstressing joints may be made when approved.
Changes in line or gradient that exceed the limitations specified shall be made with fittings specified. When polyethylene piping is installed underground, foil-backed magnetic tape shall be placed above the pipe to permit locating with a magnetic detector. After laying of pipe and testing, trench shall be backfilled to 12 inches over pipe with compacted bank sand within 12 hours of inspection and then tested.
All exposed ends are to be capped immediately during installation. Remaining backfill is to be select soil compacted in eight-inch layers to finish grade. In rocky areas the gas pipe must maintain a minimum cover of 24 inches, in accordance with 49 CFR The contractor shall be required to excavate the trench if there is rock present. The engineer must approve all areas that will have the inch cover. Excavation under pond areas shall be performed as indicated on drawing details.
Pipe joints shall be designed and installed to effectively sustain the longitudinal pullout forces caused by the contraction of piping or superimposed loads. Threaded Steel Joints. Threaded joints in steel 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. Caulking of threaded joints to stop or prevent leaks will not be permitted. Welded Steel Joints.
All gas pipe weldments shall be as indicated. Changes in direction of piping shall be made with welding 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 welding 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.
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. Polyethylene Pipe Jointing Procedures.
Jointing procedures shall conform to AGA Indiscriminate heat fusion joining of plastic pipe or fitting made from different polyethylene resins by classification or by manufacturer shall be avoided if other alternative joining procedures are available. If heat fusion joining of dissimilar polyethylenes is required, special procedures are required. The method of heat fusion joining dissimilar polyethylene resins shall be shop- and field-tested prior to adoption.
Connections between Metallic and Plastic Piping. Connections shall be made only outside, underground and with the approved transition fittings. Valve boxes of cast iron not less than three-sixteenths-inch thick shall be installed at each underground valve, except where concrete or other type of housing is indicated. Valve boxes shall be provided with locking covers that require a special wrench for removal.
A wrench shall be furnished for each box. The valve box shall be protected against movement by a suitable concrete slab at least two feet square. When in a sidewalk, the top of the box shall be in a concrete slab two feet square and set flush with the sidewalk. Boxes shall be adjustable extension-type with screw or slide-type adjustments. Valve boxes shall be separately supported, not resting on the pipe, so that no traffic loads can be transmitted to the pipe. All persons fusing on gas pipe must hold a current Eagle Mountain City certification.
Any new contractor shall have sufficient proof of prior experience and also obtain an Eagle Mountain City certification. All contractors shall provide as-builts of gas mains and service lines upon completion of the project in a timely manner. If a contractor is found in violation of the items in the checklist in this section, a stop work order will be issued until the matter is resolved.
All certifications must be renewed annually. Chapter Steel Pipe. Pipe Threads. Sealants for Steel Pipe Threaded Joints. Service lines shall be polyethylene pipe.
Minimum depth shall be 24 inches. The coatings shall consist of one of the following: 1. Minimum distance for placement of structures and facilities near main transmission lines: 1. As used in this subsection C: a. The width of a recorded easement when the width is described; ii.
Fifteen feet when the width of a recorded easement is undefined; or iii. Subsection C 2 a of this section does not apply if: i. Buy this book Better World Books When you buy books using these links the Internet Archive may earn a small commission.
Share this book Facebook. Last edited by WorkBot. December 15, History. An edition of A. This edition was published in by A. Written in English — 41 pages. Subjects Gas-pipes , Plastic Pipe. Other causes of static charge include gas flow disrupters such as pipe elbows, valves, neckdowns, and leaks.
This can be done with smaller-diameter pipe, typically two inches or less. Other similar techniques such as dissipating the static charge buildup with wet rags or a bare copper wire are used but may not be as effective. This is an update to the manual by the same title. The manual covers: technical descriptions of various plastic gas piping materials; engineering considerations; procurement consideration and acceptance tests; installation considerations; training, field inspection and pressure testing; maintenance, operation and emergency control procedures.
Formulas have been given a more generic format to permit, for instance a change in the design factor, when approved; and material specifications for polyamide have been added.
It is indexed for convenient use and contains about pages. Your Alert Profile lists the documents that will be monitored. If the document is revised or amended, you will be notified by email.
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