Moving and lowering metallic gas pipelines.
(1) A gas pipeline company may not move or lower cast iron pipe or metallic pipe with mechanical or threaded joints.
(2) Except for the pipe referenced in subsection (1) of this section, a gas pipeline company may move or lower metallic line pipe with an MAOP of sixty psig or less, which has a nominal diameter of two inches or less, if the gas pipeline company can certify that no undue stresses will be placed on the pipeline and that it can be moved or lowered in a safe manner. The gas pipeline company must consider factors such as the type of materials, proximity to fittings, joints, and welds, and any other factors that could place undue stress on the gas pipeline or create an unsafe condition.
(3) Before moving or lowering a gas pipeline other than the line pipe described in subsection (2) of this section, each gas pipeline company must prepare a study to determine whether moving or lowering will cause an unsafe condition. The gas pipeline company's engineering department must review, approve, and retain the study for the life of the pipeline. The study must analyze the following factors:
(a) The required deflection of the pipe;
(b) The diameter, wall thickness, and grade of pipe;
(c) The characteristics of the pipeline;
(d) The terrain and class location;
(e) The present condition of the pipeline;
(f) The anticipated stresses of the pipeline including the safe allowable stress limits; and
(g) The toughness of the steel.
(4) The gas pipeline company must conduct a leak survey within thirty days from the date the company moves or lowers any gas pipeline under the provisions of subsection (2) of this section.
[Statutory Authority: RCW
80.01.040,
80.04.060 and
81.88.040. WSR 08-12-046 (Docket PG-070975, General Order R-549), § 480-93-175, filed 5/30/08, effective 6/30/08. Statutory Authority: RCW
80.04.160,
80.28.210, and
80.01.040. WSR 05-10-055 (Docket No. UG-011073, General Order No. R-520), § 480-93-175, filed 5/2/05, effective 6/2/05. Statutory Authority: RCW
80.01.040. WSR 92-16-100 (Order R-375, Docket No. UG-911261), § 480-93-175, filed 8/5/92, effective 9/5/92.]