| 摘要 |
The shutdown valve design is comprised of a housing in which a gate slides from an open to a closed position in a guillotine type motion. At one end of the housing is an unobstructed bore, which is the air through flow passage, and which has a longitudinal ax is perpendicular to the guillotine movement of the gate and the main body of the housing. In the closed position, the gate completely obstructs the air flow through passage. Two compression springs are installed inside the housing so that they push against two extensions on the circumference of the gate, and which force the gate into t he closed position if it is not held in the open position by a latching mechanism. The gate is pulled into the open position, against the spring force, by a flexible member (example: stee l cable, wire, chain) that is attached to the gate at one end, and to a spool within the housing or alternatively a remote actuator outside the housing, at the other end. Rotation of the spool within the housing wraps the flexible member and pulls the gate into the ope n position. Similarly, pulling on the flexible member by a remote mounted actuator would also move the gate into the open position. The gate is typically held in the open position by a latching spindle that operates perpendicular to the rotation of the spool within the housing, and which can move via a compression spring into a located mating hole in the circumference of the spool, creating a restriction to the spools rotation. With the spool so restricted, the gate would remain in the open position until the latching spindle is pulled out through manual, electric, or hydraulic/pneumatic means. Similarly, a latching spindle would restrict the movement of a remote mounted actuator, and therefore the valve gate, until released by manual, electric, or hydraulic/pneumatic means.
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