Unibloc-Pump UNIBLOC-PD 501, Operation & Service Manual

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UNIBLOC-PD Operation & Service Manual: PD501-576 19
6.0 Relief Valve Cover Settings and Maintenance
UNIBLOC pumps may be supplied with one of the relief valve covers, shown in figure 6.0, that will minimize or eliminate
problems associated with over pressurizing the pump. Relief valve covers are useful when external relief systems are not practi-
cal. No. 3237 functions only in one direction and must be oriented such that the high pressure, or discharge, side of the pump is
always at the inlet of the relief valve. No. 3239B functions in both directions. The pressure is set in conjunction with a pressure
gauge installed on the discharge side of the pump. By compressing or decompressing the spring inside the valve, the pressure at
which the valve will open can be adjusted. This must be done while the pump is operating at the desired flow rate. Extreme cau -
tion should be used to prevent damage to the pump or other equipment that is pressure sensitive. If the pump is used to handle hot
liquids, do not touch the pump or the valve without protection.
FLOW FLOW FLOW FLOW
Relief Cover
P/N 3237
Relief Cover
P/N 3239B
Figure 6.0