| 摘要 |
<p>A valve assembly for use in for example a stirrup pump. The valve assembly has a body defining a bore into which a carrier (16) is inserted. The carrier (16) defines a tubular passageway with a pair of 0-rings (20,21) spaced apart along the length of that passageway. The passageway is of substantially uniform internal diameter and the O-rings (20,21) are received in annular grooves formed in the inside surface of the passageway. Two balls (22,23) are provided - each associated with one of the O-rings (20, 21) and an inlet port is provided which communicates with the space in the passageway between the 0-rings (20,21). The application of an excess pressure to the port drives fluid from the port through one of the O-rings (20,21) whereas the application of a reduced pressure to the port draws fluid through the other 0-ring to the port.</p> |
