Ram-type blowout preventer

摘要

An improved blowout preventer having a body with a central bore and aligned opposed passages extending out from the central bore, a ram assembly in each of the passsages and including a ram body with a face seal, a rear slot, a first passage through the body from above the face seal into the slot, a second passage through said body from below the face seal into the slot, a pressure responsive actuator, a connector extending from the actuator to the ram body and having a disc end positioned in and movable axially in said slot to close and open flow through said ram body passages, a third passage through said ram body from above said face seal to the rear of the ram body, a fourth passage through said ram body from below said face seal to the rear of the ram body and means coacting with said third and fourth passages to allow fluid flow to the rear of said ram body and to prevent fluid flow to the front of said ram body.