Pulsafeeder Pulsar Shadow - Manual (Page 6)

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1. Introduction
1.1 General Description
PULSAR metering pumps are positive displacement reciprocating pumps. They combine the high
efficiency of the plunger pump with diaphragm sealing to prevent product leakage. Each pump consists
of a power end and a process end separated by a hydraulically operated diaphragm. Individual pumps
will vary in appearance due to various liquid ends, accessories, and multiplexing; however, the basic
principles of operation remain the same.
2. Principles Of Operation
2.1 Overall Operation
Figure 1
A piston reciprocates within an accurately sized cylinder at a preset stroke length, displacing an exact
volume of fluid. This piston does not pump chemicals: it pumps hydraulic oil. The piston and
associated mechanisms are enclosed in the eccentric box that also serves as a hydraulic oil reservoir. A
diaphragm separates the oil from the product pumped. The diaphragm moves in exact response to
piston displacement. The diaphragm does no work, and acts only as a separator. Consequently, oil
displacement is translated into equal product displacement. Piston retraction causes the product to enter
through the suction check valve. Piston advance causes the discharge of an equal amount of the product
through the discharge check valve.