The equipment requiring pressure test for air separation equipment and pipeline system shall be carried out according to its own technical requirements. Before the pressure test, the pipe butt weld shall be inspected as qualified according to the standard requirements. All safety valves and automatic valve position holes in switching process shall be blocked with blind plates.
The pressure test preparation has the following requirements:
2) After verification, the accuracy is not lower than grade 1.5, and there are not less than 2 pressure gauges for pressure test with a range of 1.5-2 times the maximum measured pressure;
3) Pipe sections and equipment shall be segmented according to different pressure test pressures, and each section of instruments participating in pressure test shall be isolated or removed with blind plates;
4) The valve in the pressure test section is closed, and the inlet and outlet sections are closed with blind flanges.
Basic provisions: the test pressure shall be determined according to the pressure test procedures. If it is unclear, it shall be determined according to 1.15 times of the pipeline design pressure (the water pressure is generally 1.25 times). When boosting, first increase the pressure to 50% of the test pressure, check whether there is leakage, and if so, relieve the pressure and repair welding. After that, increase the test pressure by 10% each time, stop for 3min, increase the test pressure by 5 times, close the inlet valve and stabilize the pressure for 10min. If there is no leakage and deformation, the strength test is qualified. Then depressurize to the design pressure, check whether there is leakage point, and the pressure holding time shall be implemented according to the pressure test procedures and regulations. If the leakage rate does not exceed 5%, that is, the residual rate should reach more than 95%, it is qualified for pressure test.
DEAR air separation strictly controls each stage, quality first, and achieves customer satisfaction.
