Valve rubber seals testing methods have their own set of standards, detailed as follows:

(1) Testing of physical properties of rubber materials should be carried out according to the following standards: GB/T6031-1998 Determination of Hardness of Vulcanized Rubber or Thermoplastic Rubber (10-100 IRHD), GB/T528-1998 Determination of Tensile Stress-Strain Properties of Vulcanized Rubber or Thermoplastic Rubber, GB/T7759-1996 Vulcanized Rubber, Thermoplastic Rubber at Normal Temperature, High Temperature and Temperature. Determination of Compression Permanent Deformation at Low Temperature, GB/T 1685-2008 Determination of Compressive Stress Relaxation of Vulcanized Rubber or Thermoplastic Rubber at Normal Temperature and High Temperature, GB/T 1690-2006 Test Method for Liquid Resistance of Vulcanized Rubber or Thermoplastic Rubber, and GB/T 7762-2003 Static Tensile Test for Ozone Crack Resistance of Vulcanized Rubber or Thermoplastic Rubber.

(2) When testing the hygienic properties of rubber materials, it should be tested according to one of the following standards: GB/T 17219-1998 "Safety Evaluation Criteria for Domestic Drinking Water Transport and Distribution Equipment and Protective Material" and BS 6920:2000 "Seeing the applicability of water used by people through the influence of non-metallic products on water quality".

(3) The sealing performance test of rubber parts shall be carried out according to GB/T 13927-2008 "Industrial Valve Pressure Test" after the rubber parts and valves are assembled into finished products. For urban water supply valves, the following points should be noted

1) The test medium is clean tap water, and the test temperature is normal. After the test, the inner chamber should be cleaned.

2) The maximum allowable leakage rate of seal test is A, i.e. zero leakage, and there is no visible leakage during the duration of test pressure.

3) Gate valves and butterfly valves should be sealed bidirectionally. CJ/T 261-2007 "Butterfly Valve for Water Supply and Drainage" stipulates that when the sealing pressure is allowed to be reduced, the reverse sealing pressure should not be lower than 70% of the forward sealing pressure.

4) Gate valves and butterfly valves should be tested for low pressure sealing. CJ/T 216-2005 "Soft Sealed Gate Valve for Water Supply and Drainage" stipulates that the test pressure does not exceed 0.02 MPa, and the duration is not less than 60 dry.