Safety valves and maximum relief free air capacity:
For full table - rotate the screen!
|Max. Relieving Capacity of Free Air (cfm) |
|Gauge Pressure (psi) |
- 1 inch = 25.4 mm
The relief capacity for a safety valve depends on
- the relief discharge area
- the compressibility factor of the actual gas
- the temperature of the gas
- the geometry of the safety valve
A safety relief valve must be capable of relieving the capacity of the connected compressor(s) at operating pressure. Note that the relief pressure can not be set higher than the maximum rated working pressure of any equipment in the system. If the operating pressure is right below the relief pressure of the valve the valve may start leaking.
A "rule of thumb" is to set the relief pressure 10% above the working pressure of the system.
Sizing and dimensions of control valves & equipment in steam and condensate systems.
Air, LNG, LPG and other common gas properties, pipeline capacities, sizing of relief valves.
Heating systems - capacity and design of boilers, pipelines, heat exchangers, expansion systems and more.
Factors of Safety - FOS - are important in engineering designs.
Safety valves with boilers ranging 275 to 1500 kW.
Required hot water expansion volume in open, closed and diaphragm tanks.
Sizing safety valves after boiler output power in low pressure systems (kW and Btu/hr).
Calculate pilot operated relief valves in liquid systems.
Calculate length of safety valves vent pipes.
Calculating relief valves in gas and vapor systems.
Calculate spring operated relief valves in liquid systems.