Valve Inspection

(1) For valves used in pipelines conveying highly toxic fluids, toxic fluids, and flammable fluids, and for valves used in pipelines conveying non-flammable fluids or non-toxic fluids with a design pressure greater than 1MPa or a design pressure less than or equal to 1MPa and a design temperature less than -29℃ or greater than 186℃, shell pressure tests and sealing tests shall be carried out one by one. Those that fail the test shall not be used.

(2) For valves used in pipelines conveying non-flammable fluids, non-toxic fluids, and pipelines with a design pressure less than or equal to 1MPa and a design temperature between -29℃ and 186℃, 10% of the valves shall be sampled from each batch, and not less than 1, and the shell pressure tests and sealing tests shall be carried out. If the valves fail the test, the sample inspection shall be doubled; if the valves still fail the test, the batch of valves shall not be used.

(3) The shell test pressure of Lined Valve shall not be less than 1.5 times the nominal pressure, and the test time shall not be less than 5 minutes. The valves shall be qualified if there is no leakage in the shell packing; the sealing test shall be carried out at the nominal pressure, and the valve disc sealing surface shall be qualified if there is no leakage.

(4) For valves that pass the test, the internal water shall be drained and blown dry in time. Except for valves that need to be degreased, anti-rust oil should be applied to the sealing surface, the valve should be closed, the inlet and outlet should be sealed, obvious marks should be made, and the "Valve Test Record" should be filled in according to the prescribed format.
(5) For gate valves with a nominal pressure less than 1MPa and a nominal diameter greater than or equal to 600mm, shell pressure test and gate seal test do not need to be carried out separately. The shell pressure test should be carried out at the test pressure of the pipeline system during the system pressure test. The gate seal test can be inspected by color printing and other methods. The color printing on the joint surface should be continuous.
(6) For valves with steam jackets, the jacket part should be pressure tested at 1.5 times the steam working pressure.
(7) Safety valves should be debugged according to the opening pressure specified in the design documents. The pressure should be stable during pressure adjustment. Each safety valve should be opened and closed for no less than 3 times. After debugging, the "Safety Valve Initial Debugging Record" should be filled in according to regulations.