Extension Welded Ball Valve2019-12-28
How to solve the problem of heating without heating2020-02-27
Hydraulic tests are carried out at negative temperatures during winter construction.
Consequence: The tube freezes quickly due to the rapid freezing in the tube during the hydrostatic test.
Measures: Try to carry out hydraulic pressure test before winter application, and blow the water after pressure test, especially the water in the valve must be cleaned, otherwise the valve will rust lightly, and frost crack in heavy.
The project must be carried out at a positive indoor temperature during the hydrostatic test in winter, and the water should be blown off after the test.
The pipeline system was not flushed carefully before completion, and the flow rate and speed did not meet the pipeline flushing requirements. Even hydraulic pressure test leaks instead of flushing.
Consequences: The water quality does not meet the requirements of the pipeline system operation, and often results in reduction or blockage of the pipeline section.
Measures: Use the maximum set flow in the system or the water flow speed which should not be less than 3m / s for flushing. It shall be qualified that the color and transparency of the water at the outlet and the color and transparency of the water at the inlet are consistent with visual inspection.
Sewage, rainwater, and condensate pipes are concealed without a closed water test.
Consequences: May cause water leakage and user loss.
Measures: The closed-water test work shall be strictly checked and accepted in accordance with the specifications. Concealed sewage, rainwater, and condensate pipes, such as those buried underground, inside the ceiling, and between pipes, must be leak-proof.
In the hydraulic system strength test and tightness test of the piping system, only the pressure value and water level change are observed, and the leakage inspection is not enough.
Consequence: Leakage occurs after the pipeline system runs, which affects normal use.
Measures: When the pipeline 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 particularly necessary to carefully check whether there is a leakage problem.
Butterfly valve flanges use common valve flanges.
Consequences: The size of the butterfly valve flange is different from that of the ordinary valve flange, and some flanges have small internal diameters, while the butterfly valve has a large disc, which can cause the valve to fail to open or hard to open, which will damage the valve.
Measures: The flange should be processed according to the actual size of the butterfly valve flange.
No holes or embedded parts are reserved in the construction of the building structure, or the size of the reserved holes is too small and the embedded parts are not marked.
Consequences: During the construction of heating and sanitary engineering, picking up the building structure, or even cutting off the reinforced steel bars, affects the safety performance of the building.
Measures: Familiarize yourself with the construction drawings of the heating and sanitary engineering. According to the needs of the installation of pipelines and hangers, take the initiative to carefully cooperate with the reserved holes and embedded parts in the construction of the building structure, and refer to the design requirements and construction specifications.
When the pipe is welded, the misalignment of the pipe after the joint is not on a center line, there is no gap in the joint, the thick-walled pipe does not shovel the groove, and the width and height of the weld do not meet the requirements of the construction code.
Consequence: The misalignment of the pipe is not directly on the centerline, which directly affects the welding quality and the quality of the look and feel. There is no gap at the mouth, no beveling for thick-walled pipes, and the welding can not meet the strength requirements when the width and height of the weld do not meet the requirements.
Measures: After welding the pipe counterparts, the pipes must not be staggered and must be on a center line; gaps should be left at the counterparts; thick-walled pipes should be shoveled. In addition, the width and height of the weld shall be welded in accordance with the requirements of the code.