The testing method for valve rubber seals has its own set of standards, detailed as follows:

(1) The physical property testing 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 "Determination of Compression Permanent Deformation of Vulcanized Rubber or Thermoplastic Rubber at Room Temperature, High Temperature and Low Temperature", GB/T1685-2008 "Determination of Compression Stress Relaxation of Vulcanized Rubber or Thermoplastic Rubber at Room Temperature and High Temperature", GB/T1690-2006 "Liquid Resistance Test Method of Vulcanized Rubber or Thermoplastic Rubber", and GB/T7762-2003 "Static Tensile Test for Resistance of Vulcanized Rubber or Thermoplastic Rubber to Ozone Cracking".

(2) When there are requirements for the hygiene performance testing of rubber materials, the test should be conducted according to one of the following standards: GB/T 17219-1998 "Safety Evaluation Standards for Drinking Water Transmission and Distribution Equipment and Protective Materials" and BS 6920:2000 "Applicability of Non metallic Products to Water Used by Contact with People through the Influence of Non metallic Products on Water Quality".

(3) The sealing performance test of rubber parts should be conducted in accordance with GB/T 13927-2008 "Industrial Valve Pressure Test" after the rubber parts are assembled into finished products with valves. For urban water supply valves, the following points should also be noted.

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

2) The maximum allowable leakage rate for the sealing test is Class A, which means zero leakage and no visible leakage during the duration of the test pressure.

3) Gate valves, butterfly valves, etc. should be sealed in both directions. According to CJ/T 261-2007 "Butterfly Valves for Water Supply and Drainage", when reducing the sealing pressure, the reverse sealing pressure should not be lower than 70% of the forward sealing pressure.

4) Gate valves, butterfly valves, etc. should undergo low-pressure sealing tests. CJ/T 216-2005 "Soft sealed gate valves for water supply and drainage" stipulates that the test pressure shall not exceed 0.02 MPa and the duration shall not exceed 60 seconds.