| 摘要 |
<p>A combined air vent and overpressure relief valve for a submersible pump includes a single tubular housing to be inserted in an opening in the upper end wall of a chamber on the outlet pressure side of the pump. The upper end of this housing has a vent hole therethrough, and inside the housing is an annular valve seat facing upwardly. A valve disk within the housing is proportioned to move lengthwise thereof toward and away from the valve seat but is normally biased into sealing engagement with the seat by a spring within the housing. This valve disk has a bleed hole therethrough, and a valve ball is caged in the lower part of the housing, below the valve seat for movement into and out of sealing engagement with the lower end of the bleed hole in the valve disk as the pressure within the chamber rises and falls. If that pressure exceeds the force of the spring holding the valve disk closed, the disk will be forced out of sealing engagement with its seat in the housing, thereby providing a flow path for liquid around the periphery of the disk to and through the vent hole in the upper end wall of the housing.</p> |
