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, or with tape and tightly fitting canvas or other suitable material.

(4) Two openings may not remain uncovered at the same time.

(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 in par. (b) 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 135.246 History History: Cr. Register, October, 1999, No. 526, eff. 11-1-99.

PSC 135.279 PSC 135.279 Copper pipe addition [49 CFR 192.279]. After the text in 49 CFR 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 135.279 History History: Cr. Register, October, 1999, No. 526, eff. 11-1-99.

PSC 135.307 PSC 135.307 Inspection of materials addition [49 CFR 192.307]. After the text in 49 CFR 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 135.307 History History: Cr. Register, October, 1999, No. 526, eff. 11-1-99.

PSC 135.309 PSC 135.309 Repair of steel pipe addition [49 CFR 192.309]. After 49 CFR 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. Section 192.309 (b) pertains to transmission lines and mains intended to operate at hoop stresses of 20% or 40% or more of the specified minimum yield strength. However, applicable portions of these paragraphs shall apply to facilities intended to operate below this hoop stress level.

PSC 135.309 History History: Cr. Register, October, 1999, No. 526, eff. 11-1-99.

PSC 135.319 PSC 135.319 Installation of pipe in a ditch additions [49 CFR 192.319].

PSC 135.319(1) (1) After 49 CFR 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.

PSC 135.319(2) (2) After 49 CFR 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 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.

PSC 135.319(3) (3) After 49 CFR 192.319(c), insert:

(cw) The provisions of 49 CFR 192.319(a) shall also apply to mains operating at less than 20% of the SMYS.