| 摘要 |
<p>A device for controlling or metering fluid flow in either direction through a conduit. The device comprises an elongated body having two end walls forming an internal chamber therebetween. Each end wall further having an aperture extending axially therethrough. Disposed within the chamber is a free floating piston having a first metering orifice and a second metering orifice extending therethrough. Fluid flow through the device urges the piston against the end wall in the direction of fluid flow. In this position, the end wall in the direction of fluid flow closes off the second metering orifice while fluid is permitted to pass through the first metering orifice and into the aperture in the end wall in the direction of fluid flow. Upon a flow reversal, the piston is urged against the opposite end wall. In this position, fluid will flow through the second metering orifice in the piston and exit into the aperture in the end wall in the direction of fluid flow. The device is adapted for use in a reversible vapor compression air conditioning system. In this application, the sizes of the two metering orifices are different so that one can provide proper metering for cooling mode operation and the other can provide proper metering for heating mode operation.</p> |
