Pump Solutions Group Neptune Series 600 dia-PUMP MODELS 610 thru 647 - Manual (Page 10)

4.0.2 To reset the relief valve to a higher pressure (the relief valve setting cannot be reduced because of
design considerations), instructions are as follows:
4.0.21 Connect a test set-up shown in Figure IV below. NOTE: All parts must have a working
pressure rating above the required set pressure.
4.0.22 Start and run the pump until air is relieved from the discharge liquid (hand valve open).
4.0.23 Remove relief valve cap (FIG. #0120).
4.0.24 Close hand valve; pressure gauge should read between 250 and 4500 psi depending on pump
model.
4.0.25 Use 5/16” Allen wrench to adjust spring tension by turning relief valve adjusting screw (FIG.
#0119).
(1) To increase pressure, turn relief valve adjusting screw (FIG. #0119) in.
(2) To decrease pressure, turn relief valve adjusting screw (FIG. #0119) out.
4.0.26 After resetting or adjusting pressure, replace relief valve cap (FIG. #0119) completely in.
Do not attempt to set the internal relief valve more than 25% in excess of name plate rating.
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