Walchem EH Series, Instruction Manual

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13
3.0 OPERATION
3.1 Priming
Install the pump as described above. With the pump turned on, set stroke length
at 100% and frequency at 100%. If the pump is equipped with an air vent valve,
open the knob 1/2 turn. Liquid should move through the suction tubing and into
the pump head. When liquid starts running through the vent side tubing, close
the air vent knob and continue with output adjustment described below. If the
pump has no air vent valve, disconnect the discharge tubing from the injection
valve. When liquid enters the discharge tubing at the pump head, stop the pump
(set frequency knob to 0% on the R-Control module). Then reconnect the
discharge tubing to the injection valve.
If the pump does not self prime, remove the check valve housing on discharge &
suction sides to make sure valve cartridges and gaskets are in correct positions
(see section 4.2 for correct orientation).
Note: Pumps with FC liquid ends should use flooded suction when priming, due
to the hard valve seat material.
3.2 Adjustment
A.
EZ Pumps using the ‘D’ Control Module
If less than full output is required, set the frequency to the appropriate percentage
of maximum desired.
Example: Model EZB20D1-VE has maximum output of 1.5 GPH.
Desired output is 1.2 GPH. 1.2 ÷ 1.5 = 0.8 or 80%
Set the frequency of the pump to 0.8 x 360 = 288 spm by
pushing the UP or DOWN arrow keys.
B. EH Pumps using the ‘R’ Control Module
The pump will operate best with the stroke length at 100%. If less than full
output is required, set the frequency to the approximate percentage of maximum
desired.
Example: Model EHB20R1-VC has maximum output of 1.5 GPH.
Desired output is 1.2 GPH. 1.2 ÷ 1.5 = 0.8 or 80%
Set the frequency knob at 80.
For outputs less than 2% of maximum it will be necessary to also reduce the
stroke length. (Minimum recommended stroke length is 40%.)
C. EH Pumps using the ‘Y’ Control Module
The pump will operate best with the stroke length at 100%. If less than full
output is required, set the frequency to the desired strokes per minute using the
UP and DOWN arrow keys.
Example: Model EHB20Y1-VC has maximum output of 1.5 GPH.
Desired output is 1.2 GPH. 1.2 ÷ 1.5 = 0.8 or 80%
Set frequency of the pump to 0.8 x 360 = 288 spm by pushing the UP
or DOWN arrow keys.
For very low outputs it will be necessary to also reduce the stroke length.
(Minimum recommended stroke length is 40%.)