PDFWAC 480-75-420
Hydrostatic test requirements.
The following minimum requirements apply to a pipeline company when it conducts a hydrostatic test of a new or existing pipeline:
(1) If a pipeline company uses a manifold for hydrostatic testing, the company must provide an isolation valve between the pressure testing manifold and the pipeline being tested. The isolation valve must be rated for the manifold test pressure when in the closed position. The pipeline company must separately pressure test the manifold used in the actual pressure test to at least 1.2 times the pipeline test pressure, but not less than the discharge pressure of the pump used for the pressure testing.
(2) If a pipeline company uses a pressure relief valve to protect the pipe, each such valve must be of adequate capacity and set to relieve at ten percent above the hydrostatic test pressure. The pipeline company must calibrate the relief valve within one month prior to the hydrostatic test.
(3) The pipeline company may use a bleed valve to protect the pipeline from overpressure. When a pipeline company uses a bleed valve, the valve must be readily accessible in case immediate depressurization is required.
(4) All equipment such as hoses, piping, and other equipment used to hydrostatically test the pipe must be rated for at least the target pressure.
(5) The pipeline company must maintain documents identifying how each hydrostatic test was conducted. Each document must be signed by a person with sufficient knowledge, certifying that the document contains accurate information about the test. The documents must contain the following information:
(a) The date of the test;
(b) A test chart or other record that shows that the pressure was maintained at the minimum test pressure throughout the entire test;
(c) Beginning and ending times of the test;
(d) Beginning and ending temperatures; and
(e) Highest and lowest pressure achieved.
(6) The pipeline company must conspicuously post precautions such as warning signs indicating that a hazardous liquid pipeline is under test conditions.
(7) The pipeline company must notify the local government and fire department with jurisdiction in the area affected by the hydrostatic test.
(8) The pipeline company shall not add any water to the pipeline after the hydrostatic test has started. Because pressure varies significantly with changing test water temperatures, each pipeline company must take into consideration temperature variations in the test water before accepting the test results.
(9) The pipeline company must comply with applicable rules of the Washington state department of ecology addressing disposal of testing water.
[Statutory Authority: RCW 80.01.040, 80.04.060, 81.88.040. WSR 08-12-045 (Docket PL-070974, General Order R-548), § 480-75-420, filed 5/30/08, effective 6/30/08. Statutory Authority: RCW 80.01.040 and 80.04.160. WSR 02-18-032 (Docket No. TO-000712, General Order No. R-500), § 480-75-420, filed 8/26/02, effective 9/26/02.]