.~ Bypass or relief valve controls venting by movable pump chamber part
DEFINITION
Classification: 417/283
(under subclass 279) Apparatus comprising a pump which includes a movable part or portion other than the pumping member but which is normally in contact with the pumping member, the part or portion normally being biased against the pumping member by pumped fluid pressure acting thereon, and in which there is a bypass or relief valve for pumped fluid, the operation of the bypass or relief valve relieving the pressure bias on the part or portion such that it moves out of contact with the pumping member to permit fluid to pass around the pumping member from the pump discharge to the inlet.
