| 摘要 |
A improved metering valve includes a valve body, a retractable member, a control device, a feed duct and a return duct. The feed duct has a relay duct connected to a pumping system so that liquid may be directly pumped via the feed duct into the valve body. When the control device is inactive, a cock fitted into the valve body is urged by a spring to urge against an outlet of the valve body so that liquid cannot flow out therethrough. Instead, the liquid flows via a return hole into the return duct and back to the liquid reservoir. When the control device is actuated, a connecting portion thereof retracts so that the cock and a rod disposed thereon displace upwardly, so that the cock seals the return hole, allowing liquid into the feed duct and the valve body, through the through holes and out through the outlet for filling purposes. When the liquid has filled to a determined level, the control device stops and the spring will stretch so that the cock seals the outlet. Excessive liquid will flow via the return duct for recycling purposes.
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