be adjusted in time. Pressure calibration shall be conducted accor is no design requirements, opening pressure shall be 1.05~1.15 times of working pressure. Reseating pressure shall be larger than 0.9 times of working pressure. Each relief valve shall be adjusted over 3 times before considering adjustment qualified and lead sealing again. relief valve Investigation test record shall be filled.
Relief valve installation requirements
(1)The relief valve installation and commissioning must be conducted according to the following requirements: ① Vertical, no leaning. ② When put pipeline into commissioning, relief valve shall
Valve installation
1、General requirements for valve installation: (1)Valves of flange threaded connection should be conducted closed. (2)Valve and pipeline welding shall be argon-arc welding, to ensure its interior is bright and clear. When welding, valve shall be switched on to prevent partial area from overheating and deformation. When welding injection valve with high pressure, valve body shall be open, take off rubber washer incase the washer burnt out. (3)Before valve installation, installation direction shall be determined according to the fluid flow direction. (4)Valves installed in horizontal pipe shall be vertical, upward or downward tilt 45 degrees, the center line shall be aligned as far as possible. (5)When installing a cast iron valve (black and silver), shall prevent the risk of damage caused by strong connection or uneven force.
(2)The relief valve installation must be adhered to the following requirements: ① Relief valve inlet pipeline of sizes should not be less than
(7) Unqualified valve shall be disintegrated and reassemble for pressure test. (8) During strength and leak test, gas shall be discharged before rising pressure.
(6) Valves that pass the test, shall be discharged of internal water in time, coated with anticorrosive paint on sealing surface, switch off the valve, cut off the access way, wrap with plastic cloth, mark with serial number, fill with valve pressure test for store record.
Pressure for check valve pressure test shall be inducted from the inlet and the outlet shall be blocked up. During check valve test, brake valve, valve clack and valve plate shall be open.
Valve Pressure Test
(5) Brake Valve with Nominal Pressure less than 1.0MPa and Nominal Diameter larger than 600 mm can take strength and leak test together with process system, instead of test independently. Leak test of butt welding shall be taken separately, strength test can be taken together with the system pressure.