safety valve sizing
safety valve sizing
(OP)
I have a suitable formula for valve sizing, it requires data that is not readily available. Finding the fluid temperature at flow rated pressure is difficult to find, for instance sulfuric acid at 214.5 psig. Any help is appreciated.
Barry17
Barry17





RE: safety valve sizing
For other relief cases, the analyses can be more difficult, what is the case(s) you are looking at?
RE: safety valve sizing
In the past,I have flow tested valves using air, pushing 20,000 scfm through the valve with the supply air temp at 520R and the temp at the nozzle being 475R. The flowing temperature is not the temperature of the product within the vessel.
Hope this help
Barry17
RE: safety valve sizing
You should get a copy of NFPA 30 "Flammable and Combustible Liquids Code". There is a formulas and a procedure to calculate the heat input due to a fire under a tank and the Pressure Safety Valve flow rate to vent off the vapor to keep the pressure below the vessel design pressure.
You can convert the heat input to a flow rate and conver the vapor flow rate to a equivalent air flow rate in Standard Cubic Feet per Minute or Hour.
Having the air flow rate SCFM or SCFH will allow you to look up a valve in the manufacturers catalog that will suite the need.
I have a spread sheet based on NFPA 30 which will do this calculation. My Email address is dlandis@tpdesignbuild.com
Email me your Email address and I will send you a copy.