Relief Valve-Orifice size
Relief Valve-Orifice size
(OP)
Hi,
I search a formula to determine the orifice sizes of my relief valves. The operating pressure is 70 bars (Class 600). I know the flow (Oil and Gas) which circulate in my pipes (2300m3/h at 70bars).
How do I fix opening pressure? What are the flow to evacuate?
Thanks you to help me.
I search a formula to determine the orifice sizes of my relief valves. The operating pressure is 70 bars (Class 600). I know the flow (Oil and Gas) which circulate in my pipes (2300m3/h at 70bars).
How do I fix opening pressure? What are the flow to evacuate?
Thanks you to help me.





RE: Relief Valve-Orifice size
However, API 520 and 521 will tell you a lot.
Best regards
Morten
RE: Relief Valve-Orifice size
You'll need to know so of the gases properties like Cp and mole weight. You need the operating condtions of temperature. You need to know the process and where the gas comes from or how it is generated. You'll need to know about the pipe and vessels. Where the gas will be evacuated too.
RE: Relief Valve-Orifice size
Meanwhile, for Crude oil I find a orifice size too large and it doesn't exist in industry. I conform to formula for liquid, but here, with the oil (for thermal expansion and for the fire), the fluid to evacuate it's vapor or mixing gas/liquid.Is it correct?
Does someone know how I must proceed?
Futher more, I search a breather valve to limit the expansion phenomenon (with simultaneous opening and closing). Does it exist for a class 600.
Thanks you for your help.
RE: Relief Valve-Orifice size
If you find this i would double check the calculations.
If the calculations are correct then you can use more than one valve in parallel.
A breather valve for a class 600 systems seems contradictionary? But stranger things are seen i guess.
Check with the vendors e.g. Tyco (Anderson Greenwood, Crosby etc).
Best regards
Morten
RE: Relief Valve-Orifice size