Selection of safety valve type and back pressure
Thread Content
There is currently a safety valve with an operating pressure of 0.29 MPAG and a design pressure of 0.6 MPAG; it discharges to a high-pressure flare at a pressure of 0.4 MPAG. Using safety valve calculation software: 1. The balanced diaphragm type safety valve was selected, but the system indicated that the valve is under too high a pressure. According to discussions on forums, the balanced diaphragm type is suitable only when the back pressure is between 10% and 30% of the set pressure. 2. The pilot-operated type safety valve was selected, but the system suggested adding a backflow protector. Question: 1. What is a reverse current protector? 2. In cases where the pressure being suppressed is higher than the set pressure of the safety valve, what type of safety valve is suitable? Thank you all!
A backflow protector is used when the pressure at the outlet of a safety valve might be higher than the pressure at the inlet. When the back pressure is high and the pressure difference required for opening and closing is small, a pilot-operated safety valve is probably more suitable
What type of safety valve did the original poster choose later?