Pipe valves must be checked before installation.

1. Check carefully that the valve type and specifications meet the drawing requirements.
2. Check the valve stem and disc opening for flexibility, jamming and skewing.
3. Check the valve for damage and whether the threaded valve thread is positive and intact.
4. Check that the combination of the valve seat and the valve body is firm, the valve flap and the valve seat, the valve cover and the valve body, and the valve stem and the valve flap are coupled.
5. Check that the valve gasket, packing and fasteners (bolts) are suitable for the nature of the working medium.
6. The old or long-lasting pressure reducing valve should be disassembled, and dust, sand and other debris must be cleaned with water.
7. Clear the port cover, check the degree of sealing, and the valve flap must be closed tightly.