Liq. mixt. injection metering pump - has high speed piston pump and diaphragm pump with manual bypass upstream of press. limiting valve

摘要

The metering pump injects an additional amount of liq into a high pressure liquid line. It comprises a high-speed reciprocating piston pump (12) with inlet (12, 3) and outlet. A pressure limiting valve is connected to the outlet and a diaphragm pump (14), of which the first chamber is connected with the outlet at a point upstream of the valve (13). The diaphragm separates the first chamber from a second chamber. This has an inlet and an outlet, each provided with check valves. A manually controlled by pass live (15, 3) permits flow from the first to the second chambers via a non-return valve, when the shut-off valve (15, 8) is open.