Lincoln 84852 Troubleshooting guide

LINCOLN Models 84852, 84853, 84855, 84856
1“AIR-POWERED DIAPHRAGM PUMP
Series “B”
OPERATING AND
SERVICE INSTRUCTIONS
HAZARD WARNING
POSSIBLE EXPLOSION
HAZARD can result if 1,1,1,
-Trichloroethane, Methylene
Chloride or other Halogenated
Hydrocarbon solvents are used
in pressurized fluid systems
having Aluminum or Galvanized
wetted parts. Death, serious
bodily injury and/or property
damage could result. Consult
with the factory if you have
questions concerning Haloge-
nated Hydrocarbon solvents.
Donotuseforpumping flam-
mable materials. Build up and
discharge of static electricity
may result in afire and/or ex-
plosion causing personal injury
and loss to property.
Principle of Operation
The pump is powered by compressed
air which alternately pressurizes the
inner sides of the two diaphragm cham-
bers while simultaneously exhausting
OPERATING INSTRUCTIONS, SERVICE MANUAL
AND REPAIR PARTS LIST
the opposite inner chambers causing
the diaphragms, which are connected
by ashaft, to move endwise. Since air
pressure is applied over the entire sur-
face of the diaphragm which is forcing
liquid to be discharged by its other side,
the diaphragm is operating under a
balanced condition during the dis-
charge stroke. This allows the unit to be
operated at discharge heads over 200
feet (61 meters) of water head.
Alternate pressurizing and exhaust-
ing of the diaphragm chamber is per-
formed by an externally mounted, pilot-
operated, four way, spool type air distri-
bution valve. When the spool is at one
end of the valve body, inlet air pressure
is connected to one diaphragm cham-
berand theother diaphragm chamber is
connected to the exhaust. When the
spool is moved to the opposite end of
the valve body, the porting of chambers
is reversed. The air distribution valve
spool is moved from one end position to
the other in the valve body by means of
an internal pilot valve which alternately
pressurizes the ends of the air distribu-
tion valve spool while simultaneously
exhausting the other ends. The pilot
valve is positively shifted at each end of
the diaphragm stroke by the diaphragm
plate’s coming in contact with the end of
the pilot valve spool and pushing it into
position for shifting of the air distribu-
tion valve. The chambers are mani-
folded together with asuction and dis-
charge check valve for each chamber to
maintain flow in one direction through
the pump.
INSTALLATION
PROCEDURES
Position the pump as close as possi-
ble to the source of the liquid to be
pumped. Avoid long or undersize suc-
tion lines and use the minimum number
of fittings.
For permanent installation involving
rigid piping, install short flexible sec-
tions of hose between the pump and
piping. This reduces strains and per-
mits easier removal of the pump for
service when required. At time of insta-
llation, inspect all external gasketed
fasteners for looseness caused by
gasket creep. Tighten loose fittings
securely to prevent leakage.
AIR SUPPLY
Do not connect the unit to an air
supply in excess of 125 PSI (8 61 bars).
Install ashutoff valve in the air supply
line to permit removal of the unit for
servicing. When connecting an air sup-
ply of rigid piping, mount asection of
flexible line to the pump to eliminate
piping strain. In permanent installa-
tions, an air line filter IS recommended.
The weight of the air supply line and
of the filter must be supported by
some means other than the air valve
cap. Failure to provide support may
result in damage to the pump. A
pressure regulating valve should be
installed to prevent pressure from
exceeding recommended limits.
OPERATION
Your pump has been tested prior to
shipment and is ready for use as received
It is completely self-priming and no ini-
tial filling with fluid is required.
If the unit is to be totally submerged,
the air exhaust must be piped above
liquid level to prevent the liquid and
foreign material from entering the air
distribution valve mechanism.
Open the inlet air valve at least one
turn to allow sufficient cycling rate for
the pump to prime (30 to 60 cycles per
minute). After pumping starts, adjust
the inlet air valve for the desired pump
ing capacity. When further opening of
the inlet airvalve increases cycling rate
without increasing the flow rate, the
pump is being starved of liquid due to
suction limitations. Further opening of
theairinlet valve will waste compressed
air. Set the inlet air valve for lowest
cycling rate that does not decrease flow
rate for most efficient operation.
LINCOLN Section -B5
Page -15D
FEB-95 FORM 402581

FREEZING OR ICING
OF EXHAUST
Icing of the air exhaust can occur
under certain conditions of tempera-
ture and humidity on compressed air
power equipment. When pump perfor-
mance suffers because of icing, anon-
sticky anti-freeze lubricant such as
KILFROST, in an air line lubricator, will
solve the problem. Icing is more likely to
occur at high discharge pressures.
If adiaphragm fails, the
pumped product or fumes can
enter the air side of the pump.
This side is exhausted through
the exhaust port (muffler).
When the product is ahazar-
dous or toxic material, the
exhaust should be piped to. an
appropriate area for safe dis-
position.
When the product source is
at ahigher level than the pump
(flooded suction), the exhaust
should be piped to ahigher
level than the product to pre-
vent spills caused by siphoning.
MAINTENANCE AFTER USE
Before maintenance or re-
pair, shut off the compressed
air line, bleed the pressure, and
disconnect the air Iinefrom the
pump. The discharge line may
be pressurized and must be bled
of its pressure. When the pump
is used for toxic or aggressive
fluids, it should be flushed clean
prior to disassembly.
When the pump is used for materials
that tend to settle out or transform from
liquid to solid form, care must be taken
after each use or during idle time to
remove them and flush the pump as
required to prevent damage.
In freezing temperatures the pump
must be completely drained when idle.
This model must be tilted to allow the
liquid from the chambers to run out of
the discharge port.
DUAL PORTED
MANIFOLD
©Indicates Change

SERVICE INSTRUCTIONS:
TROUBLESHOOTING
1.
A
B.
C.
D.
E.
2.
A.
B.
C.
D.
3.
A.
B.
Pump will not cycle
Check to make sure the unit has
enough pressure to operate and that
the air inlet valve IS open.
Check the discharge line to insure
that the discharge line is neither
closed nor blocked.
If the spool in the air distribution
valve is not shifting, check the main
spool. It must slide freely.
Excessive air leakage in the pump
can prevent cycling. This condition
will be evident. Air leakage into the
discharge line indicates aruptured
diaphragm. Air leakage from the
exhaust port indicates leakage in
the air distribution valve. See further
service instructions.
Blockage in the liquid chamber can
impede movement of diaphragm.
Pump cycles but will not pump
Suction side of pump pulling in air.
Check the suction line for air leaks
and be sure that the end of the suc-
tion line is submerged. Check flange
bolting. Check valve flanges and
manifold to chamber flange joints.
Make certain the suction line or
strainer is not plugged. Restriction
at the suction IS indicated by ahigh
vacuum reading when avacuum
gauge is installed in the suction line.
Check valves may not be seating
properly. To check remove the suc-
tion line and cover the suction port
with your hand. If the unit does not
pull a good suction (vacuum), the
check valves should be inspected
for proper seating.
Static suction lift may be too high.
Priming can be improved by elevating
the suction and discharge lines
higher than the check valves and
pouring liquid into the unit through
the suction inlet. When priming at
high suction lifts or with long suction
lines operate the pump at maximum
cycle rate.
Low performance
Capacity is reduced as the discharge
pressure increases, as indicated on
the performance curve. Performance
capability varies with available inlet
airsupply. Check air pressure at the
pump inlet when the pump is oper-
ating to make certain that adequate
air supply is maintained.
Check vacuum at the pump suction.
REPAIR KITS AVAILABLE
86252 Air End Repair Kit-All Models.
86244 Hytrel Wet End Repair Kit-Models 84852 &84856.
86245 Teflon Wet End Repair Kit- Model 84853.
86237 Buns-N Wet End Repair Kit- Model 84855.
SERVICE PARTS
Capacity is reduced as vacuum
increases. Reduced flow rate due to
starved suction will be evident when
cycle rate can be varied without
change in capacity. This condition
PartNumber
Item
No. Description Qty. Model Model Model Model
84852 84853 84855 84856
1Body, spool valve 1 240695 240695 240695 240695
2Sleeve &spool set 1240696 240696 240696 240696
3O-ring 8240697 (BN) 240697 (BN) 240697 (BN) 240697 (BN)
4Cap, end 2 240698 240698 240698 240698
5Ring, retainer 2 240699 240699 240699 240699
6Cap, valve body 1240700 240700 240700 240700
7Gasket 1N/A (BN) N/A (BN) N/A (BN) N/A (BN)
8Gasket 1N/A (BN) N/A (BN) N/A (BN) N/A (BN)
9Gasket 1N/A (BN) N/A (BN) N/A (BN) N/A (BN)
10 Pilot valve assembly 1N/A N/A N/A N/A
11 Capscrew, hex head 1 240706 240705 240705 240705
12 Washer, flat 15 240706 240706 240706 240706
13 Nut, square 1 240707 240707 240707 240707
14 Capscrew, hex head 4240708 240708 243563 240706
15 Washer, flat 4240708 240709 240709 240708
16 Capscrew, hex head 14 240710 240710 240710 240710
17 Bracket intermediate 1 240711 240711 240711 240711
18 Chamber, diaphragm 1 240712 240712 240712 240712
19 Chamber, diaphragm 1 240713 240713 240713
20 O-ring 240713 2240714 (BN) 240714 (BN) 240714 (BN) 240714 (BN)
21 O-ring 2 240655 (BN) 240655 (BN) 240655 (BN) 240655 (BN)
22 Bushing 2 240716 240716 240716 240716
23 Ring, retainer 2 240717 240717 240717 240717
24 Plunger, actuator 2N/A N/A N/A N/A
25 Bumper 2N/A N/A N/A N/A
26 Bearing, sleeve 2 240720 240720 240720 240720
27 Seal, u-cup 2 240721 (Nl) 240721 (Nl) 240721 (Nl) 240721 (Nl)
28 Nut, hex 8240722 240722 240722 240722
29 Washer, sealing 2 240723 240723 240723 240723
30 Chamber, outer 2 240724 240724 240724 240724
31 Ring, sealing 2 240725 240725 240725 240725
32 Rod, diaphragm 1 240726 240726 240726 240726
33 Bumper 2 240727 240727 240727 240727
34 Plate, outer diaphragm 2 240728 240728 240726 240726
35 Plate, inner diaphragm 2240729 240729 240729 240729
36 Diaphragm 2240730 (HY) 240730 (HY) N/A (BN) 240730 (HY)
37 Capscrew, hex head 8 240731 240731 240731 240731
38 Capscrew, hex head 4 240732 240732 243564 240732
39 Ball retainer/cap 4 240733 240733 240733 240733
40 O-ring 4244191 (BN) 240735 (TF) N/A (BN) 244191 (BN)
41 O-ring 4244192 (BN) 240737 (TF) N/A (BN) 244192 (BN)
42 O-ring 4244193 (BN) 240739 (TF) N/A (BN) 244193 (BN)
43 Spacer, ring 4---- 240740 ---- -----
44 Ball, check valve 4240741 (HY) 240742 (TF) N/A (BN) 240741 (HY)
45 Seat, check valve 4 240743 240743 240743 240743
46 Capscrew, hex head 8 240744 240744 240744 240744
47 Foot, mounting 2 240745 240745 240745 240745
48 Capscrew, flat head 4240746 240746 240746 240746
49 Pipe plug 1 240747 240747 240747 240747
50 Spring 1 240748 240748 240748 240748
51 Diaphragm, overlay 2----- 240749 (TF) ---- -----
52 Muffler 1 240750 240750 240750 240750
53 Stud 2240751 240751 240751 240751
54 Manifold 1 240752 240752 240752 240752
55 Washer, flat (not shown) 4240753 240753 240753 240753
56 Washer, flat 4 240709 240709 240709 243566
57 Manifold (Dual) 1----- ----- ----- 243565
58 Manifold 1 240752 240752 240752 -----
N/A -Not Available as aseparate item (see symbol for Repair Kit).
(Nl) Fluorinated Nitrile, (TF) Teflon, (HY) Hytrel, (BN) Buna-N

C.
D.
will be more prevalent when pump
ing viscous liquids. When pumping
thick heavy materials the suction
line must be kept as large in diameter
and as short as possible, to keep
suction loss minimal.
Low flow rate and slow cycling rate
indicate restricted flow through the
discharge line. Low flow rate and
fast cycling rate indicate restriction
in suction line or air leakage into
suction.
Unstable cycling indicates improper
check valve seating on one chamber.
This condition is confirmed when
unstable cycling repeats consistently
on alternate exhausts. Cycling that
is not consistently unstable may
indicate partial exhaust restriction
due to freezing and thawing of ex-
haust air. Use of an anti-freeze lubri-
cant in an air line lubricator should
solve this problem.
CHECK VALVE SERVICING
Whether removing cap-
screws on suction or discharge
valve retainer/cap, make sure
all pressure on suction and
discharge side of pump has
been relieved. Re-lock wire the
capscrews before continuing
use.
Need for inspection or service is
usually indicated by poor priming, un-
stable cycling, reduced performance or
the pump’s cycling but not pumping.
Inspect the surfaces of both check
valve and seat for wear or damage that
could prevent proper sealing. If pump is
to prime properly, valves must seat air
tight.
DIAPHRAGM SERVICING
Remove the eight nuts securing the
outer diaphragm chamber flange and
remove the chamber. Loosen the cap-
screw securing the diaphragm and plate
to the rod by leaving the diaphragm
engaged with the capscrews around
the outer flange, preventing rotation of
the rod. DO NOT USE AWRENCH ON
THE DIAPHRAGM ROD. FLAWS ON
THE SURFACE MAY DAMAGE BEAR-
INGS AND SEAL.
During reassembly make certain that
the rubber bumper is on the rod on each
side. install the diaphragm with the
natural bulge outward as indicated on
the diaphragm. Install the heavier plate
on the outside of the diaphragm and
make certain that the large radius side
of both plates aretoward the diaphragm.
Place the sealing washer between the
inner diaphragm plate and the end of
the rod. Tighten thecapscrew toapprox-
imately 25 ft. Ibs (3.456 kilograms/
meters). Torque while allowing the dia-
phragm to turn freely with plates. Use a
wrench on the capscrew of the opposite
side to keep rod from rotating. If the
opposite chamber is assembled, the rod
need not be held.
When reassembling the outer
chambers and the manifold, the bolts
securing the manifold flange to the
chamber should be snugged prior to
tightening the chamber bolts, to insure
that the chamber port flange is square
with the manifold flange. Finish tight-
ening the manifold flange bolts after
chamber bolting is secured.
AIR DISTRIBUTION
VALVE SERVICING
The spool and sleeve are rust and
corrosion resistant brass and hardened
stainless steel. The spool is closely
sized to the sleeve and should slide
freely. Accumulation of dirt and oils may
prevent thepump from cycling. Remove
the valve body from the center pump
housing, remove the end caps, and push
the spool out of the sleeve. Wash the
parts in cleaning solvent or kerosene,
and check the spool and sleeve for
possible roughness, nicks or scratches.
Use afine stone or crocus cloth to care-
fully remove any irregular marks on the
surfaces. When the spool slides freely
on the sleeve, coat the parts with light
oil and reassemble. The four capscrews
inserted through the valve body cap to
hold the air valve to the intermediate
section should be torqued to 150 in./lbs.
(1.728 kilograms/meter).
PILOT VALVE SERVICING
This assembly is reached by remov-
ing the air distribution valve body from
the pump and lifting the pilot valve out
of the intermediate housing.
Most problems with the pilot valve
can be corrected by replacing the o-
rings. Always grease the spool prior to
Inserting it into the sleeve. If the sleeve
IS removed from the body, reinsertion
must be at the chamfered side. Grease
the o-rings to slide the sleeve into the
valve body Securely insert the retain-
ing ring around the sleeve. When rein-
serting the pilot valve, push both plung-
ers (located inside the intermediate
bracket) out of the path of the pilot
valve spool ends to avoid damage,
PILOT VALVE ACTUATOR
SERVICING
Bushings for the pilot valve actua-
tors are held in the inner chambers with
retaining rings. An o-ring IS behind
each bushing. If the plunger has any
sideways motion check o-rings and
bushings for deterioration /wear. The
plunger may be removed for inspection
or replacement. First remove the air
distribution valve body and the pilot
valve body from the pump. The plung-
ers can be located by looking into the
intermediate. It may be necessary to
use afine piece of wire to pull them out,
The bushing can be turned out through
the inner chamber by removing the outer
chamber assembly. Replace the bush-
ings if pins have bent.
ANote about Air Valve
Lubrication
The Lincoln pump’s pilot valve and
main airvalve assemblies aredesigned
to operate WITHOUT lubrication. This
is the preferred mode of operation.
There may be instances of personal
preference, orpoor quality air supplies
when lubrication of the compressed air
supply is required. The pump air sys-
tem will operate with properly lubri-
cated compressed air supplies. Proper
lubrication of the compressed air sup-
ply would entail the use of an air line
lubricator (available from Lincoln) set
to deliver one drop of 10 wt, non-
detergent oil for every 20 SCFM of air
the pump consumed at its point of op-
eration. Consult the pump’s published
Performance Curve to determine this
It is important to remember to in-
spect the sleeve and spool set rou-
tinely. It should move back and forth
freely. This IS most important when the
air supply is lubricated. If aIubricator
is used, oil accumulation will, overtime,
collect any debris from the compressed
air. This can prevent the pump from
operating properly.
RETAIN THIS INFORMATION FOR FUTURE REFERENCE
When ordering replacement parts, list: Part Number, Description, Model Number, and Series Letter.
LINCOLN provides aDistributor Network that stocks equipment and replacement parts.