What are the precautions for installing and using valves? ? ?

1. Precautions for valve installation Before installing the valve, it is necessary to ensure that it meets the design requirements and relevant standards. Before installation, the inside of the pipeline must be cleaned to remove impurities such as iron filings, in order to prevent foreign objects from getting trapped in the valve seat. Additionally, the valve should be in a closed position during installation. When installing the valve, it is necessary to confirm that the flow direction of the medium, the installation method, and the position of the handwheel comply with the specifications. When handling and installing valves, be careful to avoid accidents caused by bumps and scratches. When lifting valves. The valve must be lifted properly at the designated lifting position; it shall not be lifted or pulled when only partial forces are applied to it. Installation of flanged valves. When connecting two flanges, it is first necessary to press the flange sealing surfaces and the gasket evenly together, thereby ensuring that the flanges are joined under equal bolt stress. When tightening bolts, use a wrench that matches the nut. When using hydraulic or pneumatic tools for tightening, be careful not to exceed the specified torque. When tightening the flange, avoid uneven force; it should be tightened in a symmetrical, alternating sequence. After installing the flange, ensure that all bolts and nuts are tight and even. 2. Precautions for valve disassembly 2.1 The general precautions for disassembly are based on those for installation. However, before disassembly, it is necessary to ensure that there is no pressure inside the pipes and valves, or to replace the medium with an inert gas. 2.2 Disassembly of flanged valves. (1) Bolts should, in principle, be removed using a wrench. (2) When removing special-shaped gaskets, cross-markings should be made in advance on the gasket and the pipe flanges, as well as on the valve flanges. (3) To protect the sealing surface of the valve flange, depending on the situation, it is possible to remove the piping attached to both flanges first, before disassembling the valve. 2.3 Disassembly of welded valves (1) When using oxygen cutting, the cutting should be carried out at the location of the weld. (2) After cutting, the residual debris inside the pipeline and the valves must be removed completely. 3. Key points for maintenance:
a) The valve should be placed in a dry and well-ventilated area, with both ends of the pipe diameter sealed to prevent dust from entering.
b) When stored for an extended period, it should be inspected regularly, and oil should be applied to its surfaces to prevent rust.
c) Before installation, it is necessary to verify that the markings on the valve match the requirements for its use.
d) During installation, the interior cavity and sealing surfaces must be cleaned, and it is important to check whether the packing is properly compressed and whether the connection bolts are tightened evenly.
e) The valve should be installed in the position specified for operation, but care must be taken to ensure ease of maintenance and operation.
f) During use, the gate valve should not be partially opened to adjust the flow rate, as this may damage the sealing surfaces when the flow velocity is high; it should either be fully open or fully closed.
g) When turning the handwheel to open or close the valve, it is not advisable to use any additional levers.
h) The moving parts should be lubricated regularly.
i) After installation, regular inspections should be carried out to remove dirt from the interior cavity, check the sealing surfaces, and assess the wear on the valve stem nuts.
j) There should be scientific and proper standards for installation procedures; maintenance should include tests of the valve’s sealing performance, with detailed records kept for reference.

Thanks for the advice from the second floor; I’ve learned something

Reply to 2# zjywwjg: Well written! I originally wanted to give you wealth, but I don’t have any; I’m really sorry! {:2_33:}