HYDRAULIC UNLOADING VALVE

摘要

A pressure relief system for a reciprocating pumping system that deintensifies pressure from the pumping system and controls relief operation with the deintensified pressure. The relief system includes a relief valve connected to the pumping system and a control system that selectively opens the relief valve when an overpressure is sensed in the pumping system. To keep the relief valve in a closed position, the control system maintains a backpressure on the relief valve using the deintensified pressure. A dump valve in the control system selectively vents the backpressure so the relief valve can open. A charging system can be used for charging the control system and for reseating the relief valve.