STRAIGHTWAY STOP VALVE Russian patent published in 2005 - IPC

FIELD: valving.

SUBSTANCE: straightway stop valve comprises housing with inlet pressure port and outlet port for flowing fluid. The housing receives closure member, driving link of the closure member connected with the handle for valve control, and single-acting positive-displacement servomotor. The pressure chamber of the servomotor is in communication with the inlet port. The straightway stop valve is provided with the preliminary loaded flexible member mounted inside the housing. The movable outlet link of the flexible member is made for permitting single action on the driving link of the closure member and its movement under the action of the flexible member from its any position to the closure position of the closure member. The single-acting positive-displacement servomotor is made so that, under the action of pressure, the pressure chamber provides the action of its output link on the output link of the flexible member directed oppositely to the direction of flexible force of the flexible member and movement of the output link in the position in which it does not act on the driving link of the closure member and driving link can freely move under the external control action between the closure position and open position of the closure member. Under the action of pressure in the pressure chamber, the output link of the flexible member is held in the mentioned above position. When there is no pressure, the output link of the positive-displacement servomotor together with the driving link returns under the action of the flexible member to the closure position of the closure member.

EFFECT: enhanced reliability.