AAON LN-140 - Manual (Page 43)

43
Vibration Levels
Vertical In-Line pumps are designed to meet vibration levels set by Hydraulic Institute Standard
HI Pump Vibration 9.6.4. Standard levels are as detailed below:
Dual Pump Specific Information
Dual Pump Flapper Valve Operating
Instructions
This unit is fitted with internal valves to
allow isolation of one pump for service and
to automatically prevent recirculation of the
flow when only one pump is running.
Procedure for Parallel or Stand-By
Pumping
Discharge and suction valve stems should be
locked in the center position. This is
indicated by both locking handles in the
vertical position and the center pin of the
locking arms (4) locked by the handles. This
procedure allows the discharge flapper
valves to pivot freely and locks the suction
valve firmly in the center position.
Procedure for Isolation of One Side
1. Stop the pump to be serviced.
2. Close and lock the suction and discharge
valves: as per instructions below.
3. Ensure seal flush line interconnection
valve is closed and drain the isolated
casing.
4. Service isolated pump as required.
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 following 3”, 4”
& 6” valve illustration and the 8” valve
illustration.