(1) Lock the stop valve in the open position. Instruct authorized personnel of the importance of not inadvertently leaving the stop valve closed and of being present during the entire period that the stop valve is closed so that they can lock it in the open position before they leave the location.
(2) Install duplicate relief valves, each having adequate capacity by itself to protect the system and arrange the isolating valves or 3-way valve so that mechanically it is possible to render only one safety device inoperative at a time.
(iw) Precautions shall be taken to prevent unauthorized operation of any valve which will make pressure limiting devices inoperative. This provision applies to isolating valves, by-pass valves, and valves on control or float lines which are located between the pressure limiting device and the system which the device protects. A method similar to s. PSC 135.xxx, in (hw), shall be considered acceptable in complying with this provision.
PSC 135.214 49 CFR s. 192.204w Addition. After 49 CFR s. 192.203, insert:
192.204w Pipelines on private right-of-way of electric transmission lines. Where gas pipelines parallel overhead electric transmission lines on the same right-of-way, the company operating the pipelines shall take the following precautions:
(a) Employ blow-down connections and relief valve vents that will direct the gas away from the electric conductors.
(b) Make a study in collaboration with the electric company on the common problems of corrosion and electrolysis, taking the following factors into consideration:
(1) The possibility of the pipeline carrying either unbalanced line currents or fault currents.
(2) The possibility of lightning or fault currents inducing voltages sufficient to puncture pipe coatings or pipe.
(3) Cathodic protection of the pipeline, including location of ground beds, especially if the electric line is carried on steel towers.
(4) Bonding connections between the pipeline and either the steel tower footings or the buried ground facilities or the ground-wire of the overhead electric system.
(c) Investigate the necessity of protecting insulating joints in the pipeline against induced voltages or currents resulting from lightning strokes. Such protection can be obtained by connecting buried sacrificial anodes to the pipe near the insulating joints or by bridging the pipeline insulator with a spark-gap or by other effective means.
PSC 135.216 49 CFR s. 192.246w Addition. After 49 CFR s. 192.245, insert:
PSC 192.246w Precautions to avoid explosions of gas-air mixtures or uncontrolled fires during construction operations. (a) Operations such as gas or electric welding and cutting with cutting torches can be safely performed on pipelines and mains and auxiliary equipment, provided that they are completely full of gas, or air that is free from combustible material. Steps shall be taken to prevent a mixture of gas and air at all points where such operations are to be performed.
(b) When a pipeline or main can be kept full of gas during a welding or cutting operation, the following procedures are recommended:
(1) Keep a slight flow of gas moving toward the point where cutting or welding is being done.
(2) The gas pressure at the site of the work shall be controlled by suitable means.
(3) Close all slots or open ends immediately after they are cut with tape, and/or tightly fitting canvas or other suitable material.
(4) Do not permit two openings to remain uncovered at the same time. This is doubly important if the two openings are at different elevations.
(c) No welding or acetylene cutting shall be done on a pipeline, main, or auxiliary apparatus that contains air if it is connected to a source of gas, unless a suitable means has been provided to prevent the leakage of gas into the pipeline or mains.
(d) In situations where welding or cutting must be done on facilities which are filled with air and connected to a source of gas and the precautions recommended above cannot be taken, one or more of the following precautions, depending upon the circumstances at the job are required:
(1) Purging of the pipe or equipment upon which welding or cutting is to be done, with combustible gas or inert gas.
(2) Testing of the atmosphere in the vicinity of the zone to be heated before the work is started and at intervals as the work progresses, with a combustible gas indicator or by other suitable means.
(3) Careful verification before the work starts that the valves that isolate the work from a source of gas do not leak.
PSC 135.217 49 CFR s. 192.279 Addition. After the text in 49 CFR s. 192.279, insert:
(1w) Copper pipe shall be joined by using either a compression type coupling or a brazed or soldered lap joint. The filler material used for brazing shall be a copper-phosphorous alloy or silver base alloy. Butt welds are not permissible for joining copper pipe or tubing.
PSC 135.218 49 CFR s. 192.307 Addition. After the text in 49 CFR s. 192.307, insert:
(1w) Detection of gouges and grooves. The field inspection provided on each job shall be suitable to reduce to an acceptable minimum the chances that gouged or grooved pipe will get into the finished transmission line or main. Inspection for this purpose just ahead of the coating operation and during the lowering in and backfill operation is required.
PSC 135.219 49 CFR s. 192.309 Addition. After 49 CFR s. 192.309 (e), insert:
(fw) Due primarily to climate conditions, gouges, grooves, notches, and dents have been found to be an important cause of steel pipe failures and an attempt shall be made to prevent or eliminate harmful defects of this nature. Subsection 192.309 (b) pertains to transmission lines and mains intended to operate at hoop stresses of 20 percent or 40 percent or more of the specified minimum yield strength. However, applicable portions of these paragraphs should also be applied to facilities intended to operate below this hoop stress level.
PSC 135.220 49 CFR s. 192.319 Additions. (1) After 49 CFR s. 192.319 (a), insert:
(aw) This includes grading the ditch so that the pipe has a firm, substantially continuous bearing on the bottom of the ditch. When long sections of pipe that have been welded alongside the ditch are lowered in, care shall be exercised so as not to jerk the pipe or impose any strains that may kink or put a permanent bend in the pipe.
(2) After 49 CFR s. 192.319 (b) (2), insert:
(3w) If there are large rocks in the material to be used for backfill, care should be used to prevent damage to the coating or pipe by such means as the use of rock shield material, or by making the initial fill with rock free material to a sufficient depth over the pipe to prevent rock damage.
(4w) Where flooding of the trench is done to consolidate the backfill, care shall be exercised to see that the pipe is not floated from its firm bearing on the trench bottom.
(3) After 49 CFR s. 192.319 (c), insert:
(cw) The provisions of 49 CFR s. 192.319 (a) shall also apply to mains operating at less than 20% of the SMYS.
PSC 135.221 49 CFR s. 192.321 Additions. After 49 CFR s. 192.321 (f), insert:
(fw) The casing pipe shall be reamed and cleaned to the extent necessary to remove any sharp edges, projections, or abrasive material which could damage the plastic during and after insertion. That portion of the plastic piping which spans disturbed earth shall be adequately protected by a bridging piece or other means from crushing or shearing from external loading or settling of backfill. Care shall be taken to prevent the plastic piping from bearing on the end of the casing.
(gw) Care shall be exercised to avoid rough handling of plastic pipe and tubing. It shall not be pushed or pulled over sharp projections, dropped or have other objects dropped upon it. Caution shall be taken to prevent kinking or buckling, and any kinks or buckles which occur shall be removed by cutting out as a cylinder.
(hw) Changes in direction of plastic piping may be made with bends, tees or elbows under the following limitations:
(1) Plastic pipe and tubing may be deflected to a radius not less than the minimum recommended by the manufacturer for the kind, type, grade, wall thickness and diameter of the particular plastic used.
(2) The bends shall be free of buckles, cracks, or other evidence of damage.
(3) Changes in direction that cannot be made in accordance with s. PSC 135.221, 192.321 (hw) (1), shall be made with elbow-type fittings.
(4) Miter bends are not permitted.
(iw) Plastic piping shall be laid on undisturbed or well compacted soil. If plastic piping is to be laid in soils which may damage it, the piping shall be protected by suitable rock free materials before back-filling is completed. Plastic piping shall not be supported by blocking. Well tampered earth or other continuous support shall be used.
PSC 135.222 49 CFR s. 192.323 Addition. After 49 CFR s. 192.323 (d), insert:
(ew) Casing requirements of highway authorities shall be followed; however, construction type shall not be any less than provided by this code.
PSC 135.223 49 CFR s. 192.324w Addition. After 49 CFR s. 192.323, insert:
PSC 192.324w Rail crossings. Whenever a steel pipeline is installed under a railroad track and a casing is not used, the operator shall install the pipeline using the methods prescribed in Gas Research Institute report number GRI-91/0285, entitled “Guidelines for Pipelines Crossing Railroads and Highways."
PSC 135.224 49 CFR s. 192.325 Addition. After 49 CFR s. 192.325 (b), insert:
(bw) If the structure is a public building where people assemble or in areas such as playground, assembly ground, or park, wherever possible the clearance shall be at least 100 feet if the main is operated at more than 100 p.s.i. but less than 500 p.s.i. and shall be at least 150 feet if operated at 500 p.s.i. or more. If these clearances cannot be maintained, then the next higher type of construction shall be used except such construction may be pressure-tested the same as the remainder of the line. No distribution main or transmission line shall be installed under buildings.
PSC 135.225 49 CFR s. 192.355 Additions. (1) After 49 CFR s. 192.355 (a), insert:
(aw) Install a check valve or equivalent if:
(1) The utilization equipment might induce a back-pressure.
(2) The gas utilization equipment is connected to a source of oxygen or compressed air.
(3) Liquefied petroleum gas or other supplementary gas is used as standby and might flow back into the meter. A three-way valve installed to admit the standby supply and at the same time shut off the regular supply, can be substituted for a check valve if desired.
(2) After 49 CFR s. 192.355 (b) (3), insert:
(4w) At locations where service regulators might be submerged during floods, either a special anti-flood type breather vent fitting shall be installed, or the vent line shall be extended above the height of the expected flood waters.
PSC 135.226 49 CFR s. 192.361 Addition. After 49 CFR s. 192.361 (f), insert:
(gw) It is recommended that service to one customer and/or one building be supplied through one service and one shut-off valve.
PSC 135.227 49 CFR s. 192.365 Addition. After 49 CFR s. 192.365 (b), insert:
(bw) Whenever gas is supplied to a theatre, church, school, factory or other building where large numbers of persons assemble, an outside valve in such case will be required.
PSC 135.228 49 CFR s. 192.371 Addition. After the text in 49 CFR s. 192.371, insert:
(aw) When coated steel pipe is to be installed as a service line in a bore, care should be exercised to prevent damage to the coating during installation. For all installations to be made by boring, driving or similar methods or in a rocky type soil, the following practices or their equivalents are recommended:
(1) When a service line is to installed by boring or driving and a coated steel pipe is to be used for the service line, the coated pipe should not be used as the bore pipe or drive pipe and left in the ground as part of the service line. It is preferable to make such installations by first making an oversize bore, removing the pipe used for boring and then inserting the coated pipe.
(2) Coated steel pipe preferably should not be inserted through a bore in exceptionally rocky soil where there is a likelihood of damage to the coating resulting from the insertion.
PSC 135.229 49 CFR s. 192.375 Addition. After 49 CFR s. 192.375 (b), insert:
(cw) Plastic service lines that are not encased shall either be installed with an electrically conductive wire having adequate corrosion resistant characteristics or protection or some other acceptable means of readily locating the buried service pipe from the ground surface shall be provided.
PSC 135.230 49 CFR s. 192.377 Additions. After the text in 49 CFR s. 192.377, insert:
(aw) Copper service lines installed within a building may not be concealed.
(bw) Ferrous valves and fittings installed on underground copper service lines shall be protected from contact with the soil or insulated from the copper pipe.
PSC 135.231 49 CFR s. 192.457 Addition. After 49 CFR s. 192.457 (c), insert:
(dw) Notwithstanding the provisions of 49 CFR s. 192.457 (b) regarding active corrosion, effectively coated steel distribution pipelines, except for those portions including services and short sections that because of their nature and installation make cathodic protection impractical and uneconomical, must, not later than August 1, 1975, be cathodically protected along the entire area that is effectively coated in accordance with this subpart.
PSC 135.232 49 CFR s. 192.505 Addition. After 49 CFR s. 192.505 (e), insert:
(fw) Except in freezing weather or when water is not available, pipelines or mains larger than 6 inches in diameter, installed in class locations 1, 2, or 3, shall be hydrostatically tested in place to at least 90 percent of the specified minimum yield strength.
PSC 135.233 49 CFR s. 192.511 Addition. After 49 CFR s. 192.511 (c), insert:
(dw) Each segment of a service line (other than plastic) intended to be operated at a pressure between 0 and 1 p.s.i.g. must be given a leak test at a pressure of not less than 50 p.s.i.g.
PSC 135.234 49 CFR s. 192.613 Additions. After 49 CFR s. 192.613 (b), insert:
(cw) When street is paved or repaved. Whenever a road or street is paved or repaved with permanent pavement, the operator shall:
(1) Check for leaks along all mains and services in the streets and abutting property with a continuous-sampling instrument capable of detecting combustible gas in air concentrations of 100 parts per million.
(2) Determine condition of pipe and joints by sample visual examination, where possible.
(3) Repair any leaks found.
(4) Replace pipe if existing pipe is corroded to such an extent that it is likely to require replacement before the street is again resurfaced.
(dw) Underground pipes. Whenever underground pipes are exposed in order to repair leaks, the utility shall record on the repair order the nature of the leak and possible cause from observation.
PSC 135.235 49 CFR s. 192.614 Addition. After 49 CFR s. 192.614 (c), insert:
(dw) All operators of natural gas pipelines shall be a member of a single, state-wide one-call system. If there is more than one state-wide one-call system, the Commission may determine which system the operators will join.
PSC 135.236 49 CFR s. 192.621 Additions. (1) After 49 CFR s. 192.621 (a) (3), insert:
(3w) No person may operate a segment of a cast iron pipe in which there are unreinforced bell and spigot joints at a pressure higher than low pressure unless it can be proven to the commission that they can be operated at a higher pressure. However, the maximum allowable operating pressure under any circumstances shall not exceed 15 p.s.i.g.
