PVC pipe installation and construction flow chart

Preparatory work—measurement and stakeout—probe pipe and underground pipeline identification—groove excavation and support—leveling and re-measurement—cushion construction—re-measurement of pipe foundation—water pipe inspection—pipe installation— – Construction of joints and inspection wells – Concrete pouring of town piers – Water pressure test and inspection and acceptance – Backfill compaction.

Pipe Accessory Installation

The installation methods of PVC-U auxiliary equipment generally include threaded connection, socket connection, flange connection, pipe hoop connection, adhesive connection, etc. Some of these connection methods are more convenient to disassemble, such as flange connection, pipe hoop connection, threaded connection, etc.; some are difficult or impossible to disassemble, such as socket connection, adhesive connection, etc. In the engineering design, the connection method should be selected according to the maintenance and operation of the auxiliary equipment. Valves, water meters, safety valves, inlet (exhaust) air valves, etc. with a nominal diameter greater than 50mm are mostly connected by threaded connections.

Pressure testing of pipes

Piping systems should be pressure tested before being put into operation. The pressure test includes two contents: strength test and water tightness test. It is generally recommended to use water as the test medium during the test.

In the strength test, after removing the air in the pipeline to be tested, increase the pressure to the required pressure value at a stable pressure increasing speed, and the pressure gauge should be placed at the lowest part of the pipeline as far as possible.

The pressure test can be carried out before or after the pipeline backfill, the pipeline should be covered with soil at certain intervals, especially for the meandering pipeline, the pipeline should be fixed in place during the pressure test. Flanged connections should be exposed for easy inspection for leaks. The test pressure of the pressure test should not exceed 1.5 times the pressure rating of the pipe or the fittings with the lowest pressure rating in the system. At the beginning, the pressure should be raised to the specified test pressure value and held for a sufficient time to ensure that the pipe is fully expanded. A process takes 2-3 hours, when the system is stable, increase the pressure to 1.5 times the working pressure, stabilize the pressure for 1 hour, carefully observe the pressure gauge, and patrol along the line, if there is no visible leakage or occurrence during the test If there is a significant pressure drop, the pipe passes the pressure test.