BS ISO 9635-2:2014 pdf free

BS ISO 9635-2:2014 pdf free.Agricultural irrigation equipment一Irrigation valves一Isolating valves
In order to verify this requirement, test the valve in accordance with Annex A, with the application of a closing torque and an opening torque equal to the minimum strength torque (mST), following which it shall satisfy the requirements of the operating tests in accordance with 5.3.3, and the seat tightness tests in accordance with 5.3.2.1 and 5.3.2.2.
The minimum strength torque shall be equal to twice the maximum operating torque given in 5.3.3. In testing gate valves as specified in 5.3.3 c), apply a minimum strength torque (mST) as set out in Annex A equal to 5 × the maximum operating torque (MOT). In the case of valves as specified in 5.3.3 d), the test is applicable only when there is an additional manual operating element.
Conduct testing in accordance with ISO 9635-1:2014, 5.3.2.1.After closing the valve by application of the maximum operating torque (see 5.3.3), the leakage rate shall not exceed rate A for resilient seated valves and shall not exceed rate B for metallic-seated valves. Maintain the test pressure for 10 min.
Except for valves to be used in a single flow direction, perform the test successively in each flow direction. 5.3.2.2 Seat tightness at low differential pressure Conduct testing in accordance with ISO 9635-1:2014, 5.3.2.2 After closing the valve by application of the maximum operating torque (see 5.3.3), the leakage rate shall not exceed rate A for resilient seated valves and shall not exceed rate B for metallic seated valves. Maintain the test pressure for 10 min.
Except for valves to be used in a single flow direction, perform the test successively in each flow direction.The endurance of isolating valves is evaluated as follows:
a) Subject the isolating valve to an endurance test as set out in Annex D at a differential pressure equal to the allowable operating pressure across the obturator.
b) Test the isolating valve in accordance with 5.3.1, 5.3.2, and 5.3.3, with the application of a torque not exceeding either.BS ISO 9635-2 pdf free download.