BS ISO 9635-1:2014 pdf free

BS ISO 9635-1:2014 pdf free.Agricultural irrigation equipment一Irrigation valves
Table 1 gives minimum values of alowable site test pressure. The manufacturer’s catalogue can indicate higher values on the condition that the requirements of this part of ISO 9635 have been verified with these higher values. In this case, allowable site test pressure shall not be less than 1,5 maximum allowable pressure or (maximum allowable pressure +5 bar).
It is considered that, with the exception of the test where work is done with small volumes of water, it is possible to control the water temperature; the hydraulic characteristics tests and the endurance tests shall be carried out at a water temperature of 4 °C to 35 °C.
Valves shall be designed to ensure a safety factor against short-term and long-term shell and obturator rupture, taking account of allowable operating pressure, maximum allowable pressure, and allowable site test pressure according to 4.3. This requirement shall not preclude any of the performance requirements given in Clause 5.
The design shall be carried out using one of the following methods.
– A calculation method using the tensile strength of the material (as defined in the relevant material standards) divided by a safety factor. For materials with time-dependent mechanical behaviour (such as plastic materials), the tensile strength shall be the 20 °C 50-year extrapolated minimum strength obtained from pressure tests on injection moulded or extruded pipes subjected to constant hydrostatic pressure at various temperatures and for different lengths of time to comply with ISO 9080.
– An experimental method, relying on pressure tests on valve shells subjected to a constant hydrostatic pressure equal to maximum allowable pressure times a safety factor. For materials with time-dependent mechanical behaviour (such as plastic materials), the test pressure shall be further multiplied by a coefficient specific to each material in order to take into account its 50-year extrapolated minimum strength and the slope of its strength regression line.
Valves can be designed with various types of end connections adapted to specific pipe systems. The connections shall fulfil the standardized requirements of the relevant pipe systems.
In order to ensure interchangeability of flanged valves, their face-to-face or centre-to-face dimensions shall comply with ISO 5752 and their flanges with ISO 7005-1, ISO 7005-2, or ISO 7005-3 (depending on the flange material). In the case of steel valves with welded ends, the end-to-end and centre-to-end dimensions shall comply with EN 12982 or EN 12627.BS ISO 9635-1 pdf download.