PN 97999-749
NM2304A-X-X(en)Page2of2

PUMP OPTION DESCRIPTION CHART

NM2304A - X 1 - X 1 1
CONTAINERSUITABILITY
PLUNGER TYPE
SPRING ARRANGEMENT
CONTAINERSUITABILITY PACKINGMATERIAL
1-Universal (Stub) C-UHMW-PE(upper and lower)
4-55 Gallon 3-Glassfilled PTFE (upper)
8- Universal (Stub) (without bung) Virgin PTFE (lower)
9- 55 Gallon (without bung) 5-Glass filled PTFE / Leather staggered (upper)
A- Stub Follower Plate Virgin PTFE (lower)
B- Universal(St ub) with alternate bung
SPRINGARRANGEMENT PLUNGERTYPE
1-Coil 1- Standard (Carbon Steel)
PACKINGMATERIAL

GENERAL DESCRIPTION

The two-ball design provides for easy priming of the lower foot valve.
Thedouble acting feature is standard in all ARO industrial pumps. Mate-
rial is delivered to the pump discharge outlet on both the up and down
stroke.
The motor is connected to the lower pump endwith a spacer tube and
solventcup. This allows for lubrication of the upper packing gland and to
prevent air motor contamination because of normalwear and eventual
leakage through the material packing gland.
WARNING HAZARDOUSPRESSURE. Do not exceed maxi -
mumoperating pressure of 600 p.s.i. (41.4 bar) at 150 p.s.i.(10.3
bar) inlet air pressure.
PUMP RATIOX MAXIMUM PUMP
INLET PRESSURE TOPUMP MOTOR =FLUID PRESSURE
Pumpratio is an expression of the relationship between the pump motor area and the
lowerpump end area. EXAMPLE: When 150 p.s.i. (10.3 bar) inlet pressure is supplied
tothe motor of a 4:1 ratio pump it will develop a maximum of 600 p.s.i. (41.4 bar)fluid
pressure(at no flow) - as the fluid control is opened, the flow rate will increase asthe
motorcycle rate increases to keep up with the demand.
WARNING Referto general information sheet for additional
safety precautions and important information.
NOTICE:Thermal expansion can occur when the fluid in the materi-
al lines is exposed to elevated temperatures. Example: Material
lineslocated in a non-insulated roof area can warm due to sunlight.
Install a pressure relief valve in the pumping system.
Replacement warning label (pn 94520) is available upon request.

TROUBLE SHOOTING

Pump problems can occur in either the air motor section or the lower
pumpend section. Use these basic guidelines to help determine which
section is affected. Be sure to eliminate any possible non-pump prob-
lems before suspecting pump malfunction.
Pump will not cycle.
•No pressure to the motor.See motor manual.
•Restricted return lines. Clean obstruction.
•Damaged motor.Service motor.
No material at the outlet (pump continually cycles).
•Checkthe material supply, disconnect or shut off the air supply and
replenish the material, reconnect.
Material on one stroke only (fast downstroke).
•The lower check may not be seating in the foot valve (see lower
pump disassembly). Remove the check from the foot valve, clean
andinspect the valve seat area. If check or foot valve are damaged,
replace.
Material on one stroke only (fast upstroke).
•The middle packings may be worn (see lower pump disassembly).
Replace the seals as necessary.
Materialleakage out of the solvent cup or material appears o n the
pump plunger rod.
•Tightenthe solvent cup until leakage discontinues. If this procedure
does not aid in stopping the leakage problem, the upper packings
maybe worn ( see lower pump disassembly). Replace the seals as
necessary.

PUMP CONNECTION - UPPER / LOWER

NOTE: All threads are right hand.
1. Loosen(90571) lock nut and unscrew entire pump from the air mo-
tor.This will expose (94448) adapter (see figure 2).
2. Remove(Y145-2) retaining ring and (90572) connector pin to re-
move pump assembly from the air motor.
3. Remove (Y15-21) cotter pin and (94048) clevis pin to remove
(94448) adapter.
Lower Pump Plunger
Pump Motor
Piston Rod
Y15-21 Cotter Pin
PUMP CONNECTOR DETAIL
Figure 2
94048 Clevis Pin
Y145-2 Retaining Ring
90571 Lock Nut (ref.)
90572 Connector Pin
94448 Adapter
REASSEMBLY
1. Assemble(94448) adapter to air motor rod, aligning through holes.
2. Assemble(94048) clevis pin through hole, securing adapter.
3. Assemble(Y15-21) cotter pin through clevis pin.
4. Assemble(94448) adapter into (90584) plunger, aligning through
holes.
5. Assemble (90572) connnector pin through hole, securing with
(Y145-2) retaining ring.
6. Screwthe lower pump assembly to the air motor.
7. Screw(90571) lock nut against air motor base and tighten to 50 - 60
ft lbs (67.8 - 81.3 Nm).