1. Check whether there are defects such as sand holes and cracks on the inner and outer surfaces of the valve body.
2. Check whether the valve seat and valve body are firmly connected, whether the valve core and valve seat are matched, and whether the sealing surface has defects.
3. Check whether the connection between the valve stem and valve core is flexible and reliable, whether the valve stem is bent, and whether the thread is damaged or corroded.
4. Check whether the packing and gasket are aged and damaged, and whether the valve is flexible when opening.
5. There should be a nameplate on the valve body, and the valve body and nameplate should include: manufacturer name, valve name, nominal pressure, nominal diameter and other identification.
6. The opening and closing position of the valve during transportation should meet the following requirements:
(a) Valves such as gate valves, stop valves, throttle valves, butterfly valves, foot valves, and regulating valves should be in the fully closed position.
(b) The closing parts of plug valves and ball valves should be in the fully open position.
(c) The diaphragm valve should be in the closed position and must not be closed too tightly to prevent damage to the diaphragm valve. (d) The valve disc of the check valve should be closed and fixed.
7. Spring-type safety valves should have lead seals, and lever-type safety valves should have a positioning device for a heavy hammer.
8. The disc or valve core of the check valve should move flexibly and accurately without eccentricity, displacement or skewness.
9. The inner surface of rubber-lined, enamel-lined and plastic-lined valves should be flat and smooth, and the lining should be firmly bonded to the substrate without defects such as cracks and bubbles.
10. The flange sealing surface should meet the requirements and should not have radial scratches.
11. The valve should not be damaged, missing parts, corroded, or have nameplates falling off, and the valve body should not be dirty.
12. Both ends of the valve should be protected by protective covers, and the handle or handwheel should be flexible to operate without jamming.
13. The valve quality certificate should include the following:
(a) Manufacturer name and date of manufacture.
(b) Product name, model and specifications.
(c) Nominal pressure, nominal diameter, applicable medium and applicable temperature.
(d) Based on the standard, inspection conclusion and inspection date.
(e) Factory number, signature of the inspector and the person responsible for inspection.
