AAON LC-054 - Manual (Page 34)

34
Procedure for Starting the Pump after
Servicing:
1. Ensure serviced pump is fully re-
assembled including all seal flush lines and
drain plugs.
2. Fill the dry casing with system fluid by
opening the seal flush line interconnecting
valve and the air vent fitting.
3. Allow the pressure to equalize in the two
casings, if necessary, by opening seal flush
line interconnected valve.
4. Unlock the discharge valve as per
instructions below.
5. Unlock the suction valve as per
instructions below.
NOTE: Keep hands and tools away from
locked suction valve arm, as the differential
pressure may cause the arm to rotate quickly
with force when unlocked.
6. Close the seal flush line interconnect
valve and restart pump.
Valve Operation
Refer to the valve illustrations on the
following pages.
Discharge Valve
This valve performs the dual function of
automatically sealing the discharge of the
inactive pump when one pump is running
and can manually be closed and locked to
isolate one pump for service.
Automatic Flapper Operation
In the flapper mode the two halves of the
discharge valve are free to pivot
independently under normal operating
conditions. The locking handle (3) should be
secured with the set screw (11) in the
vertical position with the center pin of the
locking arm (4) trapped by the locking
handle (3).
Manual Valve Locking:
The locking feature of this valve is to ensure
a positive seal (leak proof) of the discharge
port on the pump to be serviced.
Note: Ensure the pump to be isolated is not
operating before attempting to release the
locking mechanism. Failure to do so may
result in injury to the operator and/or
damage to the pump.
Locking
1. Loosen discharge side set screw (11) to
release the locking handle (3).
2. Rotate the discharge side locking handle
(3) so that the handle points toward the
pump to be serviced and secure in the
horizontal position, using set screw (11).
This releases the discharge locking arm (4).
3. Rotate discharge valve shaft (16) towards
the pump to be isolated. The orientation of
the shaft is indicated by the center pin on the
locking arm. (4).
4. Raise the locking handle (3) so that the
cam on the base of the handle forces the pin
of the locking arm (4) towards the pump to
be isolated. The locking handle (3) should
be raised to between 45 degrees and the
vertical position.
5. Tighten set screw (11) to lock the locking
handle (3) in position
THIS HANDLE SHOULD NOT BE
ROTATED PAST THE VERTICAL
POSITION.
Note: Ensure the isolated pump is not
operating before attempting to release the
locking mechanism. Failure to do so may
result in injury to the operator and/or
damage the pump.