CONTROL VALVE

摘要

FIELD: valving. ^ SUBSTANCE: control valve comprises housing provided with inlet and outlet passages and receives two valving gates connected with the rod having movable drive. The first valving gate is made of a rod with step piston having openings and sealing surface. The second valving gate is made of bushing-plunger that embraces the piston and is provided with sealing surface for permitting its axial movement and locking at the end positions. The second valving gate is mounted coaxially in the seat provided with the sealing surface and sealing member. The sealing member is tubular and provided with openings made downstream of the sealing member and sealing surface. The inner diameter of the tubular part of the seat downstream of the sealing surface is mating to the outer diameter of the second valving gate, which is mounted for permitting axial movement along the tubular part of the seat from the sealing surface by means of step piston. At the end position, the sealing surface of the step piston of the rod cooperates with the sealing member. The sealing surface of the step bushing-plunger cooperates with the sealing surface of the seat. The rod is provided with piston to define the under-piston space connected with the atmosphere and above-piston space connected with the inlet passage through a passage. ^ EFFECT: enhanced reliability. ^ 1 dwg