Fluid sampling pump

摘要

A sampling pump is provided suitable for pumping a discrete quantity of either a liquid or a gas per pump stroke from a flow line to a sample vessel. An operator unit drives a piston within the pump bore, and controls the stroke of the piston and thus the quantity of fluid pumped per stroke. A balanced check valve mechanism controls flow from the pump bore to the pump outlet port, and is provided within and carried by the piston. Line pressure acts on the operator end of the piston to assist the operator in driving the piston during its power stroke. A manifold may be secured to the pump body, and has a flow path therein which is in communication with the inlet port to the pump bore. The pump may also be used for injection purposes to introduce a selected quantity of fluid to a high pressure line.