Installing valves is not an easy task. There are 14 taboos. Do you know? What happens if these taboos are violated? How to solve it?

Taboo 1: Perform hydraulic test at negative temperature during winter construction.

Consequence: The tube freezes quickly due to the rapid freezing in the tube during the hydrostatic test.

Measures: Try to perform a hydraulic pressure test before the winter application, and blow the water after the pressure test, especially the water in the cast iron gate valve must be cleaned, otherwise the valve will freeze and crack.

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. When the hydrostatic test cannot be performed, the test can be performed with compressed air.

Taboo 2: The pipeline system is not carefully flushed before completion, and the flow rate and speed cannot 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, and often causes the pipeline section to decrease or block.

Measures: Use the maximum juice flow in the system or the water flow speed 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.

Taboo 3: Sewage, rainwater, and condensate pipes are concealed without a closed water test.

Consequence: May cause water leakage and loss to users.

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 buried underground, inside the ceiling, and between pipes, must be ensured to be leak-proof.

Taboo 4: During the hydraulic pressure strength test and tightness test of the pipeline 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 especially necessary to carefully check whether there is a leakage problem.

Taboo 5: Ordinary valve flanges for 20K butterfly valve flanges.

Consequences: The size of the flange of the butterfly valve is different from that of the ordinary valve, and some flanges have a small internal diameter, while the butterfly valve has a large disc, which can cause the valve to fail to open or hard to open, causing damage to the valve.

Measures: The flange should be processed according to the actual size of the butterfly valve flange.

Taboo 6: 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 sanitation project, and actively cooperate with the construction structure to reserve holes and embedded parts according to the requirements of the installation of pipes and supports and hangers, and refer to the design requirements and construction specifications.

Butterfly Valve

Taboo 7: When welding the pipeline, the pipe misalignment after the counterpart is not on a center line, there is no gap in the counterpart, 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 tube is not directly on the center line, which directly affects the welding quality and the quality of the look and feel. There is no gap at the mouth, the bevel of thick-walled pipes is not shovel, and the width and height of the welds do not meet the requirements of strength when the welding does not meet the requirements.

Measures: After welding the pipe counterparts, the pipes must not be staggered. There must be a gap on the center line of the counterparts. Thick-walled pipes must be shoveled. In addition, the width and height of the welds should be welded in accordance with the requirements of the code.