API-RP-576

4.3.2 Applications
A safety valve is normally used with compressible fluids. Safety valves are used on steam
boiler drums and superheaters. They are also used for general air and steam services in
refinery and petrochemical plants. Safety valve discharge piping may contain a vented
drip pan elbow or a short piping stack routed to the atmosphere.
4.3.3 Limitations
Safety valves should not be used:
• in corrosive services (unless isolated from the process by a rupture disk),
• in installations that impose any backpressure unless the effects of the backpressure have
been accounted for in the installation,
• where the escape of process fluid around blowing valves is not desirable,
• in liquid service,
• as pressure control or bypass valves.
Fion Zhnag/ Charlie Chong