Problems with safety valves
Thread Content
Dear friends, how many safety valves should be installed on the pressure vessels used for generating steam? What is the basis? Thank you here.
The installation of the air tank safety valve should be in accordance with its design requirements, which should be clearly specified in the drawings; safety valves on pressure pipelines should also be installed in line with the design requirements. Generally, a pressure vessel in a system is equipped with a safety valve, while pipes do not; the same is true in reverse. References: \"Regulations on the Safety Technical Inspection of Safety Valves\" (TSGZF001-2006), \"General Requirements for Safety Valves\" (GBT 12241-2005), \"Specifications for Performance Testing of Pressure Relief Devices\" (GB T 12242-2005).
6 Selection of safety valve type 6.0.1 For discharging gases or steam, a full-opening safety valve should be used. ‘0.2 When discharging liquids, use a fully open or slightly open safety valve. 6.0.3 When releasing water vapor or air, a safety valve equipped with a wrench can be used. 6.0.4 For safety valves used with gases whose set pressure is greater than 3 MPa and temperature exceeds 235°C, safety valves equipped with radiators should be selected to prevent the discharged medium from directly eroding the spring. 6.0.5 For safety valves whose discharge medium is allowed to leak into the atmosphere, an open-type valve cap should be used; for those whose discharge is not allowed to enter the atmosphere, a closed-type valve cap should be employed. 6.0.6 For the discharge of highly toxic, highly corrosive, or extremely dangerous media, a bellows-type safety valve should be used. 6.0.7 In cases of high back pressure, a back pressure balanced safety valve or a pilot-operated safety valve should be used. 6.0.8 On some important occasions, it is sometimes necessary to install two safety valves that serve as backups for each other. Mechanical interlock devices should be used for the inlet and outlet isolation valves of the two safety valves, to ensure that the required discharge area for the container is maintained at all times, including during maintenance and repair work.
It is common to install two safety valves, one with a lower set pressure and another with a higher set pressure.