A pressure test
1.1 Each valve factory should be in accordance with GB / T 13927-1992 of the provisions of the pressure test.
1.2 The test medium
Shell strength test and the test fluid sealing medium for fresh water (which can preservatives), kerosene or other viscosity less than water, non-corrosive liquid, of austenitic stainless steel, duplex stainless steel valves, the test water chloride content should not exceed 100μg / g (100ppm), low pressure gas seal test medium is 0.4 MPa ~ 0.7 MPa compressed air or nitrogen.
1.3 Shell strength test
1.3.1 Test pressure shell test at 38 ℃ when the ball valve Nominal pressure of 1.5 times.
1.3.2 shell test, the valve stem packing seal can be adjusted to maintain the test pressure state, so that open and close like pieces in a partially open position; to a chamber filled with test medium, and gradually pressurized to test pressure, test pressure minimum sustained time in accordance with the provisions of Table 3, tests shall meet the provisions of 5.16.
1.3.3 During the test, the valve may not influence the results of external tests. Test pressure and holding pressure should be maintained during the testing period. Used as test liquid, the valve chamber should be ruled out of gas.
1.3.4 Where it should be re-repair welding of body strength test, and the test should be carried out after the repair welding and heat treatment. Non-destructive testing in need of housing should be in non-destructive testing after.
Table 3 metal sealing ball valve pressure test duration
Nominal size of shell strength test time / s static seal test shortest duration / s
DN ≤ 50 15 15
65 ≤ DN ≤ 200 60 30
250 ≤ DN ≤ 400 180 60
DN ≥ 500 180 120
Note: The test duration the valve is completely ready, in the full pressure of the examination time.
1.4 Sealing test
1.4.1 Sealing test should be conducted after the shell strength test.
1.4.2 high-pressure seal test, metal sealed ball valve, valve seat in fluid sealing test with 1.1 times the nominal pressure of the test medium for.
1.4.3 Sealing test, the closed valves at both ends, opening and closing parts are micro-open state, to the body cavity filled with test medium, and gradually pressurized to test pressure, close the opening and closing pieces, the pressure release valve at one end, the shortest duration in accordance with the provisions of Table 3. The results should be consistent with the provisions of 5.17.
1.4.4 For the two-way sealing valve, for each seat must be sealed test.
1.4.5 The structure float ball valve, test, two seat chamber between the test pressure should be filled with the medium.
1.4.6 For fixed ball upstream (import side) side of the ball valve sealing structure to carry out the upstream side of the valve seat seal test, the ball valve in the cavity between the two pressure relief valve seat hole by means of a threaded pipe observation Ball Valve leakage.
1.4.7 During the experiment, the valve should not be subject to external forces that may affect the test results should be given a way to design the valve is closed.
1.5 low pressure seal test
Low pressure seal test (when customers request it), the valve of the gas seal test gas with 0.4MPa ~ 0.7MPa tested.
2 valve wall thickness measurement
With a thickness or caliper gauge measuring body dedicated channel, in the chamber and the valve cover parts of the wall thickness.
3, material composition analysis
In the body, the sphere of the body material cuttings sampling, sampling should be 6.5 mm below the surface Department.
4 Body Material Mechanical Properties
Furnace with a valve body with the number, the same batch of heat-treated test bars according to GB / T 228 under way.
5 resistance test
For fire-resistant construction requirements of the ball, should be JB / T 6899-1993 resistance test method specified.
6 of machine with load switch test
Under normal load conditions, the switch three. Test medium pressure valve nominal pressure should be based on customer specific requirements or the manufacturer
The test pressure to determine on their own.
7 markers, nameplates check
Body surface of cast or the content and the content of the nameplate marking using visual methods, test results should be consistent with the requirements of Chapter 10.
8, protection, packaging and storage and transportation checks
Ball protection, packaging, storage using visual methods, test results should be consistent with the provisions of 11.2 and 11.3.