DEVICE FOR INSTANTANEOUS PRESSURE RELIEF Russian patent published in 1994 - IPC

FIELD: valving. SUBSTANCE: case is provided with branch pipes for connecting to a well and for pressure relief. Main valve is arranged within a space of the case for overlapping passage between the branch pipes. A rod is rigidly connected to a gate of the main valve. Free end of the rod is led out of the case. The case is provided with a locator which interacts with the rod. A gate of an additional valve is rigidly connected to the gate of the main valve through a rod. The valves are arranged on different sides of the branch pipe for connecting to the well. Cross-section area of the main valve is grater than cross-section area of the additional valve. Face space is formed between the additional valve and the case. The face space is provided with a passage having valve member for pressure relief in re-charging of the device. EFFECT: enhanced reliability. 3 cl, 1 dwg