Pipeline valve construction can not do 14 actions sewage station pipeline valve maintenance?
Taboo 1: When welding the pipeline, the wrong end of the pipe after the pair is not on the same Central Line, there is no gap on the pair, the thick wall pipe is not shovelled, and the width and height of the weld do not meet the requirements of the construction code. Consequence: The wrong end of the pipe is not in a center line directly affects the quality of welding and visual quality. There is no gap between the two sides, the thick wall pipe is not shovelled, the width and height of the weld do not meet the requirements of the welding strength requirements. Measures: After welding the pipe pair, the pipe can not be wrong, to a Central Line, the pair should be left gap, thick wall pipe to shovel groove, in addition, the width and height of the weld should be according to
No-no 1:
When welding the pipe, the wrong end of the pipe after the pair is not on the same Central Line, there is no gap on the pair, the thick wall pipe is not shovelled, and the width and height of the weld do not meet the requirements of the construction code.
Consequences:
The wrong end of the pipe is not in the same center line directly affects the quality of welding and visual quality. There is no gap between the two sides, the thick wall pipe is not shovelled, the width and height of the weld do not meet the requirements of the welding strength requirements.
Measures:
After welding the pipe pair, the pipe should not be wrong, and should be on a Central Line. The gap should be left on the pair, and the thick wall pipe should be shovelled. In addition, the width and height of the weld seam should be welded according to the specifications.
No-no 2:
For the main materials, equipment and products used in construction, there is a lack of technical quality appraisal documents or product qualification certificates in line with the national or non-promulgated current standards.
Consequences:
The project quality is not qualified, there are hidden accidents, can not be delivered on schedule, must be returned to the factory repair; Cause project delay, manpower and material input increase.
Measures:
The main materials, equipment and products used in water supply and drainage and heating and sanitation projects should meet the current standards issued by the state or the ministry of technical quality appraisal documents or product certification; The product name, model, specification, national quality standard code, date of delivery, name and place of manufacturer, inspection certificate or code of delivery shall be indicated.
No-no 3:
Valve installation procedures, models do not meet the design requirements. For example, the nominal pressure of the valve is less than the system test pressure; When the diameter of the water supply branch pipe is less than or equal to 500mm, the gate valve is used, and the dry and vertical pipes of hot water heating are used as cut-off valves. The suction pipe of the fire pump uses butterfly valve.
Consequences:
Affect the valve normal opening and closing and adjust resistance, pressure and other functions. Even cause system operation, valve damage forced repair.
Measures:
Familiar with the application scope of all kinds of valves, select the valve specifications and models according to the design requirements. The nominal pressure of the valve shall meet the requirements of the system test pressure. According to the requirements of the construction code: water supply pipe diameter less than or equal to 50mm should be used cut-off valve; Gate valves should be used when pipe diameter is greater than 50mm. The hot water heating dry, vertical control valve should use gate valve, fire pump suction pipe should not use butterfly valve.
Taboo 4:
The flange and gasket of the pipe connection are not strong enough, and the connecting bolt is short or thin in diameter. Rubber pads are used for heat pipes, asbestos pads are used for cold water pipes, and double pads or bevel pads are used with flange pads protruding into the pipe.
Consequences:
Flange joint is not tight, even damaged, leakage phenomenon. The flange liner protrudes into the pipe, which will increase the flow resistance.
Measures:
Piping flanges and gaskets must meet the requirements of piping design working pressure. The flange liner of the heating and hot water supply pipeline should be rubber asbestos pad; The flange gasket of water supply and drainage pipe should be rubber gasket. The gasket of the flange shall not burst into the tube, and its outer round to the bolt hole of the flange is appropriate. The bevel pad or several gaskets 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 flange aperture. The length of the bolt rod protruding nut should be the nut thickness. .
No-no 5:
The pipe is directly buried in the frozen soil and the loose soil without treatment, and the spacing and position of the pipe piers are improper, even in the form of dry code brick.
Consequences:
Due to the unstable support, the pipeline was damaged in the process of backfill earth tamping, resulting in rework maintenance.
Measures:
The pipeline SHALL not be buried in frozen soil and untreated loose soil, the spacing of piers shall meet the requirements of the construction code, and the support cushion shall be firm, especially at the pipeline interface, which shall not bear shear force. The brick piers should be built with cement mud to ensure integrity and firmness.
No-no 6:
In winter construction, hydrostatic test is carried out under negative temperature.
Consequences:
The pipe froze quickly during the hydrostatic test.
Measures:
Try to carry out hydrostatic test before winter application, and blow the water clean after pressure test, especially the water in the valve must be *** net, otherwise the valve will freeze crack. The project must be carried out in winter hydrostatic test, to keep the indoor temperature is positive, after the pressure test to blow the water. When the hydrostatic test cannot be carried out, the test can be carried out with compressed air.
No-no 7:
The expansion bolts used to secure the pipe supports are of inferior material, the aperture of the expansion bolts is too large, or the expansion bolts are installed on brick walls or even light walls.
Consequences:
Pipe support loose, pipe deformation, or even fall off.
Measures:
The expansion bolt must be selected as a qualified product. If necessary, it should be sampled for test and inspection. The aperture of the expansion bolt should not be greater than 2mm of the outer diameter of the expansion bolt.
Taboo 8:
Butterfly valve flange with ordinary flange.
Consequences:
Butterfly valve flange and ordinary flange size is different, some flange diameter is small, and the butterfly valve disc is large, resulting in can not be opened or hard to open the valve damage.
Measures:
Flange should be processed according to the actual size of butterfly valve flange.
No-no 9:
Do not carry out necessary quality inspection according to regulations before valve installation.
Consequences:
The valve switch is not flexible in the operation of the system, and the phenomenon of water leakage (steam) is not strictly closed, resulting in rework repair and even affecting the normal water supply (steam).
Measures:
Before installing the valve, the pressure strength and tightness test should be done. In the test, 10% of the quantity of each batch (same brand, same specification, same model) shall be randomly checked, and not less than one. The closed circuit valves installed on the main pipe and cut off should be tested for strength and tightness one by one. The VALVE strength and tightness test pressure shall comply with the “Construction Quality Acceptance Code for Building Water Supply, drainage and Heating Engineering” (GB 50242-2002).
No-no 10:
There are no reserved holes and embedded parts in the construction of the building structure, or the size of the reserved holes is small and the embedded parts are not marked.
Consequences:
In the process of heating and sanitation construction, the building structure is picked and chiseled, and even the reinforced steel is cut off, which affects the safety performance of the building.
Measures:
Be familiar with the construction drawings of heating and sanitation engineering, actively cooperate with the reserved holes and embedded parts in the construction of building structures according to the installation needs of pipelines and support hangers, and refer to the design requirements and construction specifications for details.
Taboo 11:
Sewage, rainwater, condensate pipe do not do the closed water test will do concealment.
Consequences:
May cause water leakage, and cause user losses.
Measures:
The closed water test should be checked and accepted in strict accordance with the specifications. Buried underground, inside the ceiling, between pipes and other dark sewage, rainwater, condensate pipe to ensure no leakage.
Taboo 12:
Valve installation method is incorrect. For example, the globe valve or check valve water (steam) flow direction is opposite to the sign, the valve stem is installed downward, the horizontal installation of the check valve is installed vertically, the rod gate valve or butterfly valve handle is not open, closed space, the valve stem is not facing the inspection door.
Consequences:
Valve failure, switch maintenance difficulties, valve stem down often cause water leakage.
Measures:
Install IN STRICT accordance with the valve installation instructions, open height of valve stem extension of open rod gate valve flow foot, butterfly valve fully consider the rotation space of handle, all kinds of valve stem can not be lower than the horizontal position, let alone downward. Hidden valve not only to set up to meet the valve opening and closing needs of the inspection door, at the same time the valve stem should be oriented to the inspection door.
Taboo 13:
When the water pressure strength test and tightness test of piping system, observe the change of pressure value and water level, and check the leakage is not enough.
Consequences:
Leakage occurs after the operation of the pipeline system, affecting the normal use.
Measures:
The closed water test should be checked and accepted in strict accordance with the specifications. Buried underground, inside the ceiling, between pipes and other dark sewage, rainwater, condensate pipe to ensure no leakage.
Taboo 14:
Before the completion of the pipeline system flushing is not serious, the flow rate and speed can not meet the requirements of pipeline flushing. Even water pressure strength test drainage instead of flushing.
Consequences:
Water quality does not meet the requirements of pipeline system operation, often also cause pipeline section reduction or blockage.
Measures:
Rinse with a relatively high juice flow rate in the system or a water flow rate not less than 3m/s. The water color and transparency of the outlet should be consistent with the water color and transparency of the inlet water as qualified by visual inspection.
Sewage station pipeline valve how to maintain?
Q: Sewage station pipeline valve how to maintain?
A: Sewage station there were all kinds of pipes, air pipes, sewage pipes, also has the sludge pipeline, some set up on the ground, some laid underground, in the process of operation must ensure that the pipeline flow, especially in the winter, regularly check the outdoor pipes, timing off air condensed water in the pipe, no operation of the sewage pipe and sludge water pipes to drain pipe. Do not block the live water pipe, the dead water pipe empty, air pipe water regularly.
Sewage treatment system sewage pipe, sludge pipe, after installation, to carry out thermal insulation treatment, especially the valve to focus on thermal insulation, so as not to be frozen in winter.
Post time: Oct-25-2022
