Graco 25T471, Manual

Page: 16 / 28

Operation
16 3A7931B
Prime the Pump and Pump Fluid
1. Ensure the Pump Air Regulator (AE) is closed, then
set the Ram Air Regulator (AF) to about 22 psi (0.15
MPa, 1.5 bar). Set the Ram Director Switch (AP) to
the “down” position.
2. Open the Bleed-type Master Air Switch (AC), then
set the Pump Air Regulator (AE) to 28 psi (0.2 MPa,
2 bar).
3. Open the Pump Bleeder Valve (AD), allowing air to
bleed from the pump. When the pump is fully
primed, close the valve.
4. Keep the Ram Director Switch (AP) in the “down”
position while the pump is operating.
NOTE: Adjust the air pressure to the ram as needed,
but do not increase it to a level where fluid is forced past
the wiper plate. (For 1 Gallon model only)
Change the Fluid Cartridge/Can
When the fluid has reached the minimum fill line, the
stopping valve should cut air pressure from the air motor
automatically.
For 300 CC model or 600 CC model
1. To stop the air pump but keep air pressure on the
ram, move the Bleed-type Master Air Switch (AC) to
the “OFF” position.
2. Set the Ram Air Regulator (AF) to below 30 psi
(0.21 MPa, 2.1 bar).
3. Open the dispensing valve and relieve all fluid pres-
sure in the system. Follow the Pressure Relief Pro-
cedure on page 12.
4. Set the Ram Director Switch (AP) to the “up” posi-
tion.
5. Open the Cartridge Housing (AH), then change the
fluid cartridge.
For 1 Gallon model
1. Perform the steps from 1 to 4 of 300 CC model or
600 CC model.
2. Push in the Air Assist Valve (AT) and hold it down
until the Wiper Plate (AU) leaves the top of the can.
3. Loosen clamps and remove the empty can. Set a
new full can on the ram base and position it under
the wiper plate.
4. Lower the ram and adjust the can’s position relative
to the Wiper Plate (AU). See Start and Adjust the
Ram on page 13.
F
IG
. 11: Stopping Valve Position
Stopping
Valve
NOTICE
If the fluid has thickened or solidified and the wiper
plate (AU) is stuck in the can, do not increase the set-
ting pressure of the Ram Air Regulator (AF) to
remove the Wiper Plate (AU). Excessive pressure in
the can may cause the can to rupture. If you cannot
pull the can off the Wiper Plate (AU) by hand, loosen
the two screws (AV) holding the Wiper Plate (AU) to
the pump (AA), disconnect the air tube from the Wiper
Plate (AU), and remove the can and Wiper Plate
(AU). It may be necessary to cut the can to remove
the Wiper Plate (AU).
If the can has a welded seam, position it with the seam
facing the rear of the pump to avoid injury due to splat-
tering fluid if the can leaks at the seam.