PE mining case
Used in coal mine polyethylene pipes, mainly used for coal mine water supply and drainage, ventilation, coal slurry transportation, gas drainage, etc. Polyethylene pipes for coal mines must be qualified by the National Coal Mining Machinery Quality Supervision and Inspection Center (their performances are in compliance with the national MT558.1-1996 standard), and approved by the Ministry of Coal of the People's Republic of China to be approved to use the "Coal mine safety sign" certificate.
In the standardized construction specifications, it is required that a pressure test must be performed after the installation of the mining pipe. The pressure test of the pipeline is to ensure the quality of the pipeline and eliminate some hidden dangers in the pipeline system.
1. Reduce the pressure in the PE mining pipe to atmospheric pressure, keep it for 60 minutes, and prevent air from entering the pipe. 
2. Slowly increase the pressure of the mining PE pipeline to the test pressure and stabilize the pressure for 30 minutes. If there is a pressure drop in the middle, you can inject water to make up the pressure. If the pipe joints and fittings leak, stop the pressure test immediately, find out the cause and solve the problem, and then perform the pressure test.
3. Stop the water injection and pressure stabilization and stabilize for one hour. If the pressure drops below 70% of the test pressure after one hour, you need to stop the pressure test, find out the reason and take measures, and then perform the pressure test.
Main test phase:
1. After the test phase is completed, the PE mining pipe is quickly drained and decompressed, and the general pressure reduction is 10% -15% of the test pressure.
2. Record the remaining pressure of the pipeline every three minutes for 30 minutes. If the remaining pressure has an upper body trend within 30 minutes, the pipeline test result is acceptable. If there is no upward trend in the residual pressure, you need to observe for another 60 minutes. If the entire process is 90 minutes and the pressure drop does not exceed 0.02MPA, then the test results are also acceptable.