Service And Repair
Replacing the Air Purge Screw
40
Replacing the Air Purge Screw
Disconnect, lock out, and tag power at the panel before starting to
service the pump.
When servicing unit use non-sparking tools and use caution when removing or installing
equipment to avoid generating a spark.
enerating a spark.
Kits Required:
• Air Purge Screw (P/N 410134-001),
• Hardware/Seal Kit (P/N 410154-001)
Procedure:
1.
If a ball valve is installed down line from the pump, close it.
2.
Remove and save the protective plug in the top of the check valve housing and turn the service screw
clockwise (see Figure 37). As the screw approaches its bottom position, you will hear the system
depressurizing. Continue turning the screw until it can go no further. When the screw is all the way down, back
off the screw 4 turns to lift the check valve and let the fuel drain out of the manifold’s hydraulic cavities.
3.
Unscrew the check valve housing. Notice that the check valve and spring are still attached to the service
screw. Remove and discard the housing o-ring (see Figure 28 on page 30). Set the housing/check valve
assembly aside.
4.
Remove the 2’’ NPT plug, pressure transducer, or MLLD from the pressure transducer port in the manifold.
Remove the o-ring from the device and discard.
5.
Locate the air purge screw on the top of the manifold (Figure 37).
Figure 37. Locating Air Purge Screw
6.
The air purge screw has a hitch pin that is set in the horizontal position to limit travel of the screw (see
Figure 38).
7.
Accessing the hitch pin through the check valve port, use your forefinger to push the pin all the way in as far
as you can. As you unscrew the screw, the pin will be forced down into the vertical position as it contacts the
surface of the manifold’s cavity.
8.
Lubricate the three o-rings on the new screw with petroleum jelly and install it with the hitch pin pushed on
and hanging in the vertical position (see Figure 40).
WARNING
OFF
rjpumps/fig41vsfc.eps
Air purge screw
Pressure transducer
port
Service screw (beneath protective plug)
Check valve housing