RELIEF VALVE; SAFETY VALVE; SAFETY RELIEF VALVE, which is used for different types of ventilation and the appearance is not the same!
1) RELIEF VALVE Use liquid drainage and slowly open drain, such as thermal relief valve used to drain liquid time is blocked in the tube and then continue to heat! Rated capacity at 25% pressure above P
2) SAFETY VALVE is used for rapid evaporation of steam or air, such as the boiler rated capacity at 3%, 10%, 20% above the set P.
3) SAFETY RELIEF VALVE Use either liquid or gas to drain. Like most chemical and petrochemical plants. Adjust to either pop or non-pop action !!
Ref .: API RP 520 Standard
