Pressure test and anticorrosion and heat preservation of pipeline-1

Release time:

2024-04-05

What are the requirements of pipeline pressure test?

Answer:

1) Before the pressure test, the test system shall be comprehensively inspected according to the design requirements and relevant technical specifications. The valves, instruments, accessories, etc. that are not suitable to be tested with the pipeline shall be removed from the pipeline, and the temporary short pipes shall be connected. All openings in the pipeline shall be closed, and the equipment that is not suitable to be tested together or the blind plate shall be added between the high (low) pressure system and the low (high) pressure system for isolation. After the pressure test, they shall be removed in time.

2) The valve in the pressure test system shall be opened, the vent valve shall be set at the highest point of the system, and the drain valve shall be set at the lowest point.

3) The water pressure test should not be carried out under the ambient temperature lower than 5 ℃, otherwise the corresponding anti freezing measures should be taken, or the air pressure test should be used. After the pressure test is qualified, the liquid in the system should be discharged immediately.

4) During the test, the pressure shall be increased slowly, and the condition of each part of the pressure test system shall be observed at the same time. If any problem is found, the pressure shall be reduced immediately for repair.

5) After the pressure test is qualified, the test and inspection records shall be filled in and signed by all relevant personnel for filing as technical data.

What is the allowable water seepage for the hydrostatic test of underground water supply pipeline?

Answer. When the underground water supply pipeline is subject to the strength test with water as the medium, when the pressure is increased to the test pressure and the constant pressure is not less than 10min (to maintain the pressure, it is allowed to add water into the pipe), check the interface and pipe fittings. If no damage and serious water seepage are found, the water seepage test shall be carried out for the pipeline system. If no damage is found through the water seepage test, and the water seepage is not greater than the specified allowable value, it is considered that the test is qualified (the interface with more water seepage shall be repaired).

1) Raise the water pressure to the test pressure, close the water valve of the water pump, and record the time (T) required to reduce 0.1MPa; then increase the pipeline pressure to the test pressure, and close the water valve of the water pump.

2) Quickly open the No.2 water valve, discharge water to the measuring tank, record the time (T) required to reduce 0.1MPa, and measure the discharge water (W) within this time; in addition, the opening degree of the No.3 regulating valve for water discharge of the vector tank shall be specified in advance, so that the outflow water can adapt to the allowable water seepage of the test pipe section.

What are the regulations for refrigeration system test?

Answer: the refrigeration system test must meet the following requirements:

1) blow dirty. The pressure is 0.6MPa, the medium is dry air, the Freon system can use inert gas, check with white cloth, it is qualified if there is no dirt within 5min. After purging, the valve core of the valve in the system shall be removed and cleaned (except for the safety valve).

2) The tightness test shall be maintained for 24 hours, and the pressure drop in the first 6 hours shall not be greater than 10.03mpa. In the next 18 hours, except for the error caused by the change of the ambient temperature, the pressure is qualified if there is no change.