detailed inspection
Before the pressure test, a detailed inspection shall be conducted to check the connecting valves, fittings, pumps and equipment to ensure that their performance and technical status meet the safety requirements. Connecting pipes are not allowed to be constructed at the same time, and pressure test can only be carried out when the pressure boosting conditions are really met.
Selection and installation of pressure gauge
The selection and installation of pressure gauges must meet the following conditions. It shall be marked with factory inspection qualification or unit instrument calibration, and sealed with lead. The nameplate pressure of the pressure gauge shall be 1.5-2.5 times of the test pressure. Install vertically where it is easy to observe. Generally, double watches should be installed.
Setting of exhaust valve
During the water pressure test, exhaust valves should be set at the highest and lowest points of the pipeline, so that gas can be discharged through the exhaust valve when water is supplied and sewage can be discharged through the drain valve when pressure is released. Anti-freezing measures should be taken for water pressure in winter, and sudden pressure increase caused by water temperature change should be paid attention to when testing water in summer.
It is forbidden to use gas medium for pressure test.
In general, gas medium pressure test is not allowed. In case of special circumstances, the pressure test of gas medium should be carried out with the consent of the designer, comprehensive review of relevant technical data and reliable safety measures, and approval of the unit leader and technical director.
Safe distance and warning signs
During the whole air pressure test, pipelines and equipment shall be provided with obvious warning signs or guardrails at a safe distance (90M) for necessary protection. Irrelevant personnel are strictly prohibited from entering the site, and smoking and open flames are strictly prohibited in the warning area.
Prevent system overvoltage
When the pressure test source pressure is greater than the test pressure, measures such as reducing valve, safety valve and system pressure gauge should be adopted to prevent the system from overpressure.
Pay attention to protection
During the whole air pressure test, the eyes and ears of relevant construction personnel should be in a protective state to avoid being injured by airflow. After the pressure test is completed, slowly release the pressure, dismantle the pressure test equipment, clean up the pressure test site, and ensure that there are no potential safety hazards before evacuating.
Sectional pressure test
During sectional pressure test, the pipeline connecting the pressure test must be disconnected, the thickness of the temporary blind plate should meet the strength requirements, the bolts should be tightened, the welding blind plate and the head must be welded by qualified welders, and the weld should be inspected by flaw detection, and the grade meets the requirements. After the pressure test, it should be eliminated in time.