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Opening and closing force test: 1. The opening and closing force of fire ball valves shall be tested using a Class 3 standard dynamometer or other measuring device with an equivalent precision level. 2. The testing of the opening and closing force shall be carried out in the tangent direction of the rotation of the handwheel or handle. 3. The force measurement points for the handwheel and handle should be arranged at the positions shown in Figure 1 and Figure 2, respectively. Handle with a ball joint, allowing the force measurement point to be at the center of the ball joint. 4. Prior to testing, the fire ball valve may be subjected to 10 pre-treatment cycles of full opening and full closing. 5. During testing, it shall be ensured that the pressure difference before opening or after closing the fire ball valve is equal to the nominal pressure value of that fire ball valve. Withstand voltage test 1 Test requirements: (1) The test medium shall be clean water, with a temperature ranging from 5 to 40°C. (2) During the test, the fire ball valve should not be subjected to any external forces that could affect the test results. (3) The test pressure should be gradually increased to the specified test pressure value, and kept constant throughout the duration of the test. (4) During testing, the air inside the fire ball valve body cavity should be removed. (5) The accuracy of the pressure gauge or pressure indicator used for testing shall be not lower than grade 1, with a range of approximately 1.6 times the test pressure. (6) Before the pressure test of the shell, the outer surface of the fire ball valve shall not be painted or coated with any other material that might conceal surface defects. For painted fire ball valves in stock, it is permissible to retain the coating during the shell pressure test. (7) The sealing test shall be conducted after the pressure test of the housing. (8) During the sealing test, the sealing surfaces must be cleaned thoroughly and free of oil residues. To prevent damage to the sealing surfaces, a thin layer of oil, no thicker than kerosene, can be applied. 2 Shell pressure test: Open the spherical part, seal one end of the fire ball valve, fill the interior of the shell with water from the other end, apply pressure to reach the test pressure, and then inspect the shell (including the stuffing box as well as the joints between the valve body and the valve cover). 3 Sealing test: For the fire ball valve with a specified medium flow direction, open the ball part slightly, seal the outlet end of the fire ball valve, fill the interior cavity with water from the inlet end, apply pressure up to the test pressure, close the ball, release the pressure at the outlet end, and then open the outlet end to check the sealing performance. For fire ball valves for which the medium flow direction is not specified, the other end should also be pressurized and inspected in the same manner. Static pressure life test: The static pressure life test for fire ball valves is carried out in accordance with the provisions of JB/Z 246.