Back Pressure Valve:
A back pressure valve is employed to control the pressure preceding the valve, while a safety valve is designed to shield downstream equipment from potential harm due to excessive pressure.
Upon surpassing the predetermined pressure, the back pressure valve slightly opens and resets when the pressure is released to within 1% of the preset pressure.
In contrast, safety valves open considerably and rapidly discharge pressure within the pipeline when the pressure exceeds the established threshold.
Given its sensing components and minimal pressure differential during operation, a back pressure valve usually accumulates some upstream pressure before cautiously releasing excess pressure.
Devoid of sensing elements, safety valves exhibit a significantly higher pressure differential during operation compared to back pressure valves. When appropriately chosen, a safety valve can swiftly evacuate the entire system without contributing to upstream pressure accumulation.
It's important to note that these two valve types are not interchangeable. In specific scenarios, employing both simultaneously might be necessary.