PN 97999-1128
NM2318B-X-XPage2of2
PUMP OPTION DESCRIPTION CHART
NM2318B - 1 3 - X 4 3
CONTAINER SUITABILITY
PLUNGER TYPE
SPRING ARRANGEMENT
CONTAINER SUITABILITY PACKING MATERIAL
1 - Universal (Stub) C - UHMW-PE (upper and lower)
L - Mineral filled PTFE (upper and lower)
SPRING ARRANGEMENT PLUNGER TYPE
4 - Multiple Wave Spring 3 - Standard (400 series Stainless steel with hard
chrome plating)
PACKING MATERIAL
GENERAL DESCRIPTION
WARNING
HAZARDOUS PRESSURE. Do not exceed maxi-
mum operating pressure of 2700 p.s.i. (186.2 bar) at 150 p.s.i.
(10.3 bar) inlet air pressure.
PUMP RATIO X MAXIMUM PUMP
INLET PRESSURE TO PUMP MOTOR
= FLUID PRESSURE
Pump ratio is an expression of the relationship between the pump motor area and the
lower pump endarea. EXAMPLE: When150 p.s.i. (10.3 bar) inlet pressure is supplied
to the 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 as the
motor cycle rate increases to keep up with the demand.
WARNING
Refer to general information sheet for additional
safety precautions and important information.
Thetwo-balldesign providesforeasy primingof thelowerfoot valve.
The double acting feature is standard in all ARO industrial pumps.
Material isdelivered tothe pumpdischarge outleton both the upand
down stroke.
The motor is connected to the lower pump end with a spacer tube
and solvent cup. This allows for lubrication of the upper packing
gland and to prevent air motor contamination because of normal
wear and eventual leakage through the material packing gland.
TROUBLE SHOOTING
Pump problems can occur in either the air motor section or the lower
pump end 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).
Check the 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
and inspect 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.
Material leakage out of the solvent cup or material appears on the
pump plunger rod.
Tighten the solvent cup until leakage discontinues. If this procedure
does not aid in stopping the leakage problem, the upper packings
may be worn (see lower pump disassembly). Replace the seals as
necessary.
PUMP CONNECTION -- UPPER / LOWER
DISASSEMBLY
NOTE: All threads are right hand.
NOTE 2: When disassembling lower pump end from pump, use a
wrench on the flats of (12) tube, (23) inlet body and (29) seat body
to preventfrom twisting anddamaging the tierods (see Operator’s
Manual 67310-X-X, p/n 97999-1129 for lower pump end item num-
bers).
1. Lay the pump assembly on a workbench.
2. Remove the three nuts from the three tie rods (figure 1).
3. Pull the air motor from the lower end until the motor piston rod is in
the “down” position and the lower pump end plunger is in the “up”
position.
4. Removethe cotter pinandpin, releasingmotor pistonrodfrom lower
pump end plunger.
Lower Pump Plunger
Motor Piston Rod
Y15-21-S Cotter Pin
(1/16” o.d. x 1/2” long)
PUMP CONNECTOR DETAIL
Figure 2
95498 Pin
REASSEMBLY
1. Assemble lower pump end plunger to motor piston rod, aligning
through holes.
2. Assemble pin through hole, securing rods.
3. Assemble cotter pin through pin.
4. Rotate the lower pump end so the material outlet is 180_ from the
motor air inlet.
5. Assemble the tie rods to the lower pump end.
6. Retain with three nuts.
