Previous:Xiaobian and you learn some taboos and solutions when installing Xi valves (above), today Xiaobian continues to share the second half with you

Taboo 8: Pipelines are directly buried in frozen soil and untreated loose soil, and the spacing and position of pipeline piers are improper, even in the form of dry-code bricks.

Consequences: The pipeline suffered damage during the backfill tamping process due to unstable support, resulting in rework and repair.

Measures: The pipeline shall not be buried in frozen soil and untreated loose soil, the spacing of the piers shall meet the requirements of the construction specifications, and the support pads shall be firm, especially at the pipeline interface, and shall not bear shear force. The brick piers should be built with cement mortar to ensure integrity and firmness.

Tabu 9: The expansion bolts fixed to the pipe support are of inferior material, the hole diameter of the expansion bolts is too large, or the expansion bolts are installed on brick walls or even lightweight walls.

Consequences: Pipe supports are loosened, pipes are deformed, or even fall off.

Measures: Expansion bolts must be selected qualified products, if necessary, samples should be sampled for test inspection, the hole diameter of the installation of expansion bolts should not be greater than the outer diameter of the expansion bolt 2mm, expansion bolts should be applied to concrete structures.

Taboo 10: The strength of the flange and liner of the pipe connection is not enough, and the connecting bolt is short or thin in diameter. Rubber pads are used for thermal pipes, asbestos pads are used for cold water pipes, and double pads or inclined pads are used, and flange liners protrude into the pipes.

Consequences: The flange connection is not tight, or even damaged, and leakage. The flange liner protrudes into the pipe, increasing the resistance to the flow of water.

Measures: Flanges and gaskets for pipes must meet the requirements of the design working pressure of the pipeline. The flange liner of heating and hot water supply pipelines should be rubber asbestos pads; The flange liner of the water supply and drainage pipeline should be made of rubber pad. The liner of the flange shall not protrude into the pipe, and its outer circle should be to the flange bolt hole. The bevel pad or several liners shall not be placed in the middle of the flange, the diameter of the bolt connecting the flange should be less than 2mm than the hole diameter of the flange, and the length of the protruding nut of the bolt rod should be 1/2 of the thickness of the nut.

Taboo 11: During the hydraulic strength test and tightness test of the pipeline system, only the pressure value and water level changes are observed, and the leakage inspection is not enough.

Consequences: Leakage occurs after the operation of the piping system, which affects the normal use.

Measures: When the piping system is tested according to the design requirements and construction specifications, in addition to recording the pressure value or water level change within the specified time, it is especially necessary to carefully check whether there is a leakage problem.

Taboo 12: Sewage, rainwater, and condensate pipes are concealed without a closed water test.

Consequences: May cause water leakage and cause loss to users.

Measures: The closed water test work should be inspected and accepted in strict accordance with the specifications. Underground burial, ceiling, pipe and other concealed sewage, rainwater, condensate pipes, etc. should be guaranteed to be seepage and leakage.

Tabu 13: The pipeline system is not flushed carefully before completion, and the flow rate and speed do not meet the requirements of pipeline flushing. Even a hydrostatic strength test is used to drain water instead of flushing.

Consequences: Water quality is not up to the operational requirements of the piping system, which often leads to reduced or clogged pipe sections.

Measures: Rinse with the maximum juice flow rate in the system or the water flow rate should not be less than 3m/s. The color and transparency of the water at the outlet should be consistent with the water color and transparency of the inlet water.

Taboo 14: Hydrostatic tests are carried out at negative temperatures during winter construction.

Consequences: The tube freezes quickly during the hydrostatic test, causing the tube to freeze.

Measures: Try to carry out the hydrostatic test before the winter application, and blow the water clean after the pressure test, especially the water in the valve must be cleared, otherwise the valve will freeze and crack. When the project must be tested in winter, it should be carried out at a positive indoor temperature, and the water should be blown clean after the pressure test. When hydrostatic testing is not possible, compressed air can be used for testing.