Difference between back pressure valve and safety valve
It is used to control the pressure in front of the valve, and the safety valve is used to protect the downstream equipment from high pressure damage.
Back pressure valve
It is used to control the pressure in front of the valve, and the safety valve is used to protect the downstream equipment from high pressure damage.
When the pressure exceeds the set value, the back pressure valve will open slightly and reset when the pressure is less than 1% of the set pressure.
For the safety valve, when the pressure exceeds the set value, the safety valve will open greatly and quickly discharge the pressure in the pipeline.
Since the back pressure valve has sensing elements and the pressure ratio of opening and re closing is very small, the upstream of the back pressure valve generally accumulates some pressure before the back pressure valve slightly opens to discharge excess pressure.
Safety valve
There is no sensing element, so the pressure ratio of opening and re closing is much higher than that of back pressure valve. If the type selection is appropriate, the safety valve can quickly empty the whole system without causing upstream accumulated pressure.
The two are not interchangeable. In some cases, both should be used at the same time.