| 摘要 |
A laminar flow control valve has a valve housing with an inlet and an outlet, an orifice plate, a poppet, an operating mechanism such as an electrically powered proportional solenoid, and a mechanism for realigning the poppet and orifice plate to maintain selected surfaces of those components in substantially parallel relation. The gaseous flow is throttled between respective parallel surfaces of the orifice plate and poppet such that the volumetric flow rate is linearly proportional to the pressure differential across the parallel surfaces. The poppet is mounted to a stem of the operating mechanism so as to be free to move in more than one plane relative to the orifice plate. In the embodiment illustrated, the poppet is free to swivel so that the metering surfaces "self-align" each time the valves close. The preferred embodiment of the invention utilizes a flat orifice plate and poppet. The poppet is attached to a stem of the operating mechanism by mechanical means. Other features include a pressure balancing arrangement which utilizes one or more diaphragms to desensitize the valve to pressure fluctuations.
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