BS EN ISO 10434:2004 download free.Bolted bonnet steel gate valves for the petroleum, petrochemical and allied industries.
The purpose of this International Standard is to establish the basic requirements and practices for flanged and butt-welding end steel gate valves of bolted bonnet construction that parallel those given in American Petroleum Institute API Standard 600, eleventh edition, 2001 (ISO 10434:1998). It is not the purpose of this International Standard to replace ISO 6002 or any other International Standard that is not identified with petroleum refinery, petrochemical or natural gas industry applications.
This International Standard specifies the requirements for a heavy-duty series of bolted bonnet steel gate valves for petroleum refinery and related applications where corrosion, erosion and other service conditions would indicate a need for full port openings, heavy wall sections and large stem diameters.
4 Pressure/temperature ratings
4.1 The pressure/temperature ratings applicable to valves specified in this International Standard shall be in accordance with those specified in the tables of ASME Bi 6.34 for Standard Class for the applicable material specification and the applicable Class. Restrictions of temperature and pressure, for example, those imposed by special soft seals or special trim materials, shall be marked on the valve identification plate, see 8.4.
4.2 The temperature for a corresponding pressure rating is the maximum temperature of the pressure-containing shell of the valve. In general, this temperature is the same as that of the contained fluid. The use of a pressure rating corresponding to a temperature other than that of the contained fluid is the responsibility of the user.
4.3 For temperatures below the lowest temperature listed in the pressure/temperature tables (see 4.1), the service pressure shall be no greater than the pressure for the lowest listed temperature. The use of valves at lower temperatures is the responsibility of the user. Consideration should be given to the loss of ductility and impact strength of many materials at low temperature.
4.4 Double seated valves, in some design configurations, may be capable of trapping liquid in the centre cavity of the valve when in the closed position. If subjected to an increase in temperature, an excessive buildup of pressure may occur leading to a pressure boundary failure. Where such condition is possible it is the responsibility of the user to provide, or require to be provided, means in design, installation or operating procedure to assure that the pressure in the valve does not exceed that allowed by this International Standard for the resultant temperature.BS EN ISO 10434:2004 pdf download free.