MAINTENANCE MANUAL
GP/146/99. Issue 9. October 2005
GENERAL DESCRIPTION
Diagram 1
Whilst the pump High Pressure Selector
(change over) valve is in the open
position, water which enters the high
pressure stage during the low pressure
mode will circulate back to the low
pressure stage, thus preventing high
pressure from being generated.
Diagram 2
Shows the pump in operation when both
high and low pressure may be used
simultaneously – High Pressure
Selector (change over) Valve in the
closed HP position.
Diagram 3
Shows the pump in operation in low and
high pressure mode, with the High
Pressure Selector (change over) Valve
closed. With the HP outlets closed, the
pressure relief valve opens to permit
excessive high pressure to circulate
back to the low pressure stage to
prevent over pressurisation.
Diagram 4
Illustrates an extreme case where the
pump is in full operation with all outlets
closed with both the pressure relief
valve and thermal relief valve open to
provide pressure and overheat
protection.
©Hale Products Europe LTD, Warwick
GP/146/99
WTmaint - Issue9. 10-2005October 2005
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