AAON LN-140 - Manual (Page 45)

45
Locking
1. Loosen suction side set screw (11) to
release the locking handle (3).
2. Rotate the suction side locking handle
(3) so that the handle points towards the
pump to be serviced and secure in the
horizontal position, using set screw (11).
This releases the suction locking arm
(4).
Note: The locking handle (3) should only be
rotated towards the pump stopped for
service. The suction valve is designed to
prevent the locking handle (1) from rotating
towards the running pump, as the suction of
the running pump could cause the valve to
slam shut with sufficient force to injure the
operator and/or cause damage to the pump.
Do not attempt to circumvent this safety
feature.
3. Rotate the suction valve towards the
pump to be isolated. The orientation of
the shaft is indicated by the center pin on
the locking arm (4).
4. Loosen set screw (11) and raise the
locking handle (3) so that the cam on the
base on 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.
This handle should not be rotated past the
vertical position.
5. Tighten set screw (11) to secure the
locking handle (3) in position.
Unlocking
1. Open the interconnecting valve on the
seal flush line to pressurize the serviced
pump and vent air through bleeder valve
on series 4302. Close these valves once
the pressure is equalized and air
removed.
2. Loosen set screw (11) and lower locking
handle (3) to the horizontal position,
secure with set screw (11).
NOTE: Keep hands and tools away from
suction valve locking arm when freed by
locking handle as differential pressure may
cause arm to rotate quickly with force when
unlocked.
3. Rotate valve to center position so that
the center pin of the locking arm (4) is
located in the recess on the locking
handle (3).
4. Loosen set screw (11) and raise locking
arm (3) to the vertical position, locking
the center pin in the locking arm recess,
secure with set screw.
Care should be taken when
performing procedures 3 and 4. Read
instructions carefully.
WARNING