Pulsafeeder Pulsa Series 680 EN - Manual (Page 4)

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1. Introduction
1.1 How it Works
A standard foot mounted motor drives a worm shaft at constant speed. Through worm gear reduction and
eccentric, a reciprocating power stroke is transferred to a plunger. The length of the plunger stroke
determines pump capacity and can be adjusted manually to provide pumping range from
0-100% of rating. However, this plunger does not pump chemicals, but an exceptionally stable oil*, having
excellent lubrication qualities. This makes a perfect pumping medium.
1.2 Hydraulically Balanced Flat Diaphragm Design
(Figure 2)
Using this oil, the plunger hydraulically moves a diaphragm alternately forward and backward. A
displacement from this diaphragm movement in turn, takes in the liquid (chemical) being pumped through a
suction check valve on the suction stroke of the plunger and discharges a like amount of liquid (chemical)
through a discharge check valve on a forward or discharge stroke. The plunger operating in a sized cylinder
and at exact stroke length gives exact displacement and accurate pumping rate. The diaphragm isolates the
chemical being pumped within the reagent head and check valves. No other parts need to be of special
chemically stable material. This isolation of prompt eliminates the possibility of contamination. The plunger
handles only oil and no stuffing box is required.
*A special property petroleum oil tradenamed “PULSAlube” is generally used as hydraulic fluid. Continual reference to “Oil” as hydraulic medium
implies its general use rather than its use of necessity. Check with your representative or the factory if substitute oils must be used.
(Figure 2)