| 摘要 |
A backflow preventer valve including a housing structure having inlet and outlet ports therethrough for attaching to system conduits, a chamber formed in the housing, a pair of spaced valve seats associated with one of the ports including an air space formed between the valve seats, and a movable valve assembly including a first member hingedly attached to the valve housing for movement in the chamber between a closed position adjacent to the valve seats and an open position angularly related to the closed position, and the valve assembly having a clapper portion defined by relatively movable inner and outer members, a flexible valve member including first and second portions and separate members for attaching the flexible valve member respectively to the inner and outer clapper members, the first portion of the flexible valve member being engageable with one of the pair of spaced valve seats in the closed position thereof and the second portion being engageable with the other of the pair of valve seats in the closed position thereof. The subject valve may optionally also have a discharge port communicating the space formed by and between the pair of spaced valve seats with atmospheric conditions and the valve assembly may include cooperatively engageable elements to limit the relative movement therebetween. Furthermore, the subject backflow preventer valve may include a discharge valve assembly associated with the optional discharge port to control communication therethrough.
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