Valve installation technology
First, the performance and testing before installation The performance of the valve needs to be tested before installation, in the testing process should be controlled from the following aspects:
(1) After the valve is installed, it should be ensured that it is flexible and convenient to open under water pressure. Under the effect of water pressure, the torque of the opening shall be tested with a torque wrench to ensure that the specification requirements are met.
(2) Valve closure tightness test. Under 1.1 times of water pressure, it is required that the leakage and dripping of the valve should meet the requirements of the specification, and the pressure on both sides of the valve should be tested, and it can be qualified after multiple tests; it is required for different calibers and different types of valves. For testing, the inspection should select a unit with testing qualification, and the sealing effect of the valve bearing should be evaluated during the valve load operating life testing process.
(3) The valve has a higher flow capacity. Especially for butterfly valves, the over-flow resistance of the butterfly valve must be small and the effective area of over-current should be large. This requires that all kinds of valves and valves of different types should also be tested in units that are qualified to measure the flow resistance coefficient.
(4) The capacity of the water pressure inside the valve should be consistent with the pipeline, that is, the valve can withstand the test pressure requirements of the pipeline when the valve is open.
Second, the assembly
(1) Valve and pipe connection method In order to facilitate the assembly and disassembly of the valve, a retractable expansion device is generally installed on the side of the connection between the valve and the pipe. Some companies use single-disk couplings (live flanges) for valves with DN ≤ 400 mm. ) Instead of a retention extender. At present, some valve manufacturers have valve products with retention retractors, which are welcome, but the price is higher than the price of ordinary valves plus retractors, which is unreasonable and affects its promotion.
(2) Inspection after valve assembly After the valve inspection and acceptance personnel have assembled on the valve site, they shall check the assembly conditions to see if they meet the requirements of the drawings; whether they meet the requirements of operation management; open and close inspections, and whether the opening and closing instruction readings are consistent with the actual situation. The opening and closing of the number of rotation is consistent with the instructions; large diameter pipe should also be drilled into the pipe inspection and cleaning of the sealing surface; and acceptance records, establish a good valve technology files.
Third, the operation and management Whether the valve can be opened and closed well, not only to select the appropriate valve, product quality, and meticulous construction and installation, but also to optimize the management, in order to play "a thousand days, using a temporary force" effect. Good operation management is reflected in the following three aspects:
(1) Technical data of the valve Technical data of the valve include the valve manufacturer's manual; inspection of the valve after the purchase of the valve; valve assembly and location card; valve maintenance record; for the street changes, the valve card should be updated, and strive to establish GIS management system.
(2) Valve operation and management The quality requirements of the valve operation management include the fact that the valve should be closed tightly; the valve shaft seal packing is not leak-proof; the valve is open and closed lightly and the indication is intact. The routine operation of the valve operation management includes the completion of the valve opening and closing operations and the improvement of the operation records; the valve opening and closing records of regular inspections. For valves that have not been used for a long period of time, it is necessary to set different inspection cycles according to the size of the calibre. Generally, only 10 turns of the opening and closing activities are required, and it is necessary to be more cautious if the valve is to be completely closed. For the faults discovered, a corresponding plan for major repairs should be proposed and dealt with in a timely manner. Valves that cannot be opened after a special shutdown should be treated as emergency repairs.
(3) Valve well conditions Valve well conditions include valve well masonry that meets design requirements; the well cover is intact and the road surface is intact; the hole position of the valve is accurate; there is no debris and sewage in the well; and there is no rust spot on the valve surface. Because the valve well is a closed space, it is easy to form anoxic conditions. When the conditions permit, large-diameter valve wells should take into account the technical measures for long-term convection of the air in the well; for valve wells, the inspection should be performed regularly and the pressure be buried in time. problem.
Shenyang Shaped Valve Manufacturing Co., Ltd. will serve you wholeheartedly. The company's main valves, butterfly valves, gate valves, check valves, globe valves, special-shaped butterfly valves and other valve products are welcome to negotiate with customers. Company Tel: 024-86671463