People’s Republic of China **Code for Pressure Testing and Stabilizing Water Supply Pipelines

The Industry Standard of the People’s Republic of China, \"Technical Specifications for Buried Polyethylene Water Supply Pipes,\" applies to PE water supply pipes manufactured by Guangdong Guotong New Building Materials Co., Ltd.; pipes produced by other manufacturers are not covered by these specifications. I. General rules for hydraulic testing of pipeline systems 1. The static water pressure used in hydraulic testing shall be equal to the operating pressure of the pipeline, and the test pressure should not be less than 0.80 MPa ； If the operating pressure of the pipeline is less than 0.8 MPa, the hydrostatic test pressure shall be set at 0.8 MPa. Pneumatic testing shall not be used as a substitute for hydraulic testing ； 2. After filling the pipes with water, inspect the exposed connection points that have not been backfilled (including the joints where pipes meet pipe fittings); any leaks detected must be repaired ； 3. The length of the pipeline for hydrostatic testing should not exceed 1000 m. For pipe sections with attachments in between, the length of each section to be tested under hydraulic pressure should not exceed 500 m; pipes made of different materials within the system should be tested separately. 4. The ends of the pressure testing pipe section must be checked for stability and reliability. During pressure testing, the supporting structures must not loosen or fail; valves must not be used as sealing plates. 5. Pressurization should be carried out using mechanical equipment equipped with measuring devices, whose accuracy should not be lower than grade 1.5 (with the maximum allowable error not exceeding 1.5% of the maximum scale value). The range of these devices should be 1.3 to 1.5 times the test pressure, and the diameter of the dial should be no less than 150 mm. II. Pressure Testing 1. Test Equipment Name Specification Quantity Name Specification Quantity Press / 1 unit Ball valve, 6-inch 2 units High-pressure pipe, 10 MPa, 4 meters Pressure gauge, 1.6 MPa, 1 unit Flange plates, depending on pipe diameter 2 pieces Silicone sheet, 5 mm, 1 m2 High-strength bolts, M16 (M18), 16 sets 2. Test Procedure (1) The length of the pipeline should be determined based on actual conditions, but it must not exceed 500 meters ； (2) Install sealed flange plates at both ends of the pipeline (where PE flanges have already been welded), and use silicone sheets for sealing in between. Fasten with bolts and equip with a ball valve. One end is the water inlet, and the other end is the water outlet (also known as the vent). (3) A pressure gauge should be installed at the water inlet end. (4) Using a press, slowly inject water into the pipeline under zero pressure. When filling with water, be sure to open the vent hole ； (5) Once the pipe is filled with water, close the vent hole. (6) Gradually increase the pipeline pressure (by observing the pressure gauge) until it reaches the test pressure, and maintain this pressure for 30 minutes; if the pressure drops during this period, water can be added to replenish the pressure. But it shall not be higher than the test pressure. (7) Check for any leaks at the pipe joints, fittings, etc. If there is a leak, the pressure testing must be stopped; the cause must be identified and the leak fixed before proceeding with the pressure testing according to step 5. (8) Release pressure to 50% of the maximum test pressure ； (9) If the pressure remains stable at 50% of the maximum operating pressure, or even shows an increase, it indicates no leakage ； (10) Continue the visual inspection for another 90 in; if no leakage is detected, the pressure test is considered successful.