MAINTENANCE MANUAL
GP/146/99. Issue 9. October 2005
Section 14
Pump Tests
Vacuum Test
Place the blanking cap(s) in position on the inlet(s) of the pump and close the
delivery valves. Run the pump at 1000 - 2000 rpm and observe the compound
needle. When a vacuum of .7bar is obtained, stop the pump. This vacuum should be
maintained for at least 15 sec. If a Water Ring Primer is fitted follow the same
procedure but run the pump at 2,800 rpm
If the pump will not hold the vacuum with the blanking caps in position, a leak is
present in the pump, and the pressure test detailed below must be carried out to
trace it.
Should the pump not reach a vacuum of .7bar but will hold a lower pressure, a fault
in the priming system is indicated.
Check as follows:
Check each primer drain hole for water leakage. If leakage is found, replace the
shaft glyd ring as described in section 8.
If the pump will not achieve .7bar vacuum, and will not hold what it does achieve,
there is a leak, and possibly also a fault, in the priming system.
Pressure Test
This test needs only to be carried out if the pump will not hold vacuum with blanking
cap(s) in position, and is intended to trace the leaks responsible for the loss of
vacuum.
Apply a water pressure of 3.5 - 7.0bar to the pump and check for leaks. The area
causing the leak should be visible, and can be dismantled and rectified. If no leaks
are apparent, the leakage must lie between the priming valve and the primer. Points
to be checked are:
1. The inlet seal in the primer end cap
2. The priming valve diaphragm
PRV and TRV Test
With the pump primed, and HP operation selected, close all discharges. Run the
pump at approximately 2800rpm. The HP stage pressure should not exceed 50bar if
the PRV is working satisfactorily.
Continue running the pump, to permit it to heat up. The TRV should open and
discharge water when the pump temperature is in the order of 45 - 55°C. Observe
the discharge, if it open to atmosphere, or feel the discharge pipe become warm if it
returns to the vehicle tank. Open a pump discharge valve to permit cool water to
enter the pump. The flow from the TRV should now cease.
©Hale Products Europe LTD, Warwick
GP/146/99
WTmaint - Issue9. 10-2005October 2005
34
