Pump tests – Hale SMR-U User Manual

Page 25

Section 12

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 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 glyde 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 - 7.0 bar 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

TRV Test
With the pump primed, close all discharges. Run the pump at approximately
2800rpm 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 with the low temperature option and
70-75

C with the high temperature option. 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.