PSG Wilden Original T20 Series Instruction Manual

Simplify your process
Engineering
Operation &
Maintenance
Original™Series METAL Pumps
T20
WIL-10280-E-04
REPLACES WIL-10280-E-03

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U.S.Clean Air Act
Amendmentsof 1990
The Wilden diaphragm pump is an air-operated, positive displacement, self-priming pump.These drawings show flow
pattern through the pump upon its initial stroke. It is assumed the pump has no fluid in it prior to its initial stroke.
FIGURE 1 The air valve directs pressurized air to
the back side of diaphragm A. The compressed air
is applied directly to the liquid column separated by
elastomer diaphragms. The diaphragm acts as a separa-
tion membrane between the compressed air and liquid,
balancing the load and removing mechanical stress from
the diaphragm which allows for millions of flex cycles.
The compressed air moves the diaphragm away from
the center block of the pump. The opposite diaphragm
is pulled in by the shaft connected to the pressurized
diaphragm. Diaphragm B is now on its suction stroke; air
behind the diaphragm has been forced out to the atmo-
sphere through the exhaust port of the pump. Diaphragm
A is working against atmospheric air pressure. The
movement of diaphragm B toward the center block of the
pump creates a vacuum within chamber B. Atmospheric
pressure forces fluid into the inlet manifold forcing the
inlet valve ball off its seat. Liquid is free to move past the
inlet valve ball and fill the liquid chamber.
FIGURE 2 When the pressurized diaphragm, diaphragm
A, reaches the limit of its discharge stroke, the air valve
redirects pressurized air to the back side of diaphragm
B. The pressurized air forces diaphragm B away from
the center block while pulling diaphragm A to the center
block. Diaphragm B is now on its discharge stroke.
Diaphragm B forces the inlet valve ball onto its seat due
to the hydraulic forces developed in the liquid chamber
and manifold of the pump. These same hydraulic forces
lift the discharge valve ball off its seat, while the opposite
discharge valve ball is forced onto its seat, forcing fluid
to flow through the pump discharge. The movement of
diaphragm A to the center block of the pump creates a
vacuum within liquid chamber A. Atmospheric pressure
forces fluid into the inlet manifold of the pump. The inlet
valve ball is forced off its seat allowing the fluid being
pumped to fill the liquid chamber.
FIGURE 3 At completion of the stroke, the air valve
again redirects air to the back side of diaphragm A, which
starts diaphragm B on its exhaust stroke. As the pump
reaches its original starting point, each diaphragm has
gone through one exhaust and one discharge stroke. This
constitutes one complete pumping cycle. The pump may
take several cycles to completely prime depending on the
conditions of the application.
WILDEN PUMP DESIGNATION SYSTEM SUGGESTED INSTALLATION
T20 /XXXXX/ XXX / XX /XXX / XXXX
O-RINGS
MODEL VALVE SEAT
VALVE BALLS
DIAPHRAGMS
AIR VALVE
CENTER BLOCK
AIR CHAMBERS
WETTED PARTS & OUTER PISTON
SPECIALTY
CODE
(if applicable)
®
WARNING: Possible explosion can result from Halogenated
Hydrocarbon solvents when used in pressurized fluid systems
having aluminum or galvanized wetted parts.
CAUTION: Do not exceed 125 psig air supply pressure.
(50 psig on UL models.)
CAUTION: Always wear safety glasses when operating
pump. When diaphragm rupture occurs, material being
pumped may be forced out air exhaust.
NOTE: Pump must be lubricated. Wilden suggests an arctic
5 weight oil (ISO grade 15).
WARNING: Prevention of static sparking — If static sparking
occurs, fire or explosion could result. Pump, valves, and
containers must be grounded when handling flammable fluids
and whenever discharge of static electricity is a hazard.
CAUTION: Do not exceed 125 psig air supply pressure. Blow
out air line for 10 to 20 seconds before attaching to pump to
make sure all pipe line debris is clear. Always use an in-line
filter.
CAUTION: Before any maintenance or repair is attempted,
the compressed air line to the pump should be disconnected
and all air pressure allowed to bleed from pump. Disconnect
all intake, discharge and air lines.
Viton is a registered trademark of DuPont Dow Elastomers.
WILDEN PUMP – HOW IT WORKS
CAUTIONS – READ FIRST!

1WILDEN PUMP & ENGINEERING, LLCWIL-10280-E-04
19 mm (3/4") FNPT
VALVE CONNECTOR
D
C
B
A
F
KL
N
M
P
R
ST
E
H
J
G
H
102 mm (4")
DIN (ANSI) LIQUID DISCHARGE
25 mm (1")
FNPT AIR EXHAUST
102 mm (4”)
DIN (ANSI) LIQUID INLET
NOTE: Before starting disassembly, mark a line from each
liquid chamber to its corresponding air chamber, as well as a
line from the liquid chamber to its corresponding discharge
elbow and ball pot. These lines will assist in proper alignment
during reassembly.
CAUTION: When removing the end cap using compressed
air, the air valve end cap may come out with considerable
force. Hand protection such as a padded glove or a rag
should be used to capture the end cap.
NOTE:
All non-lube-free air-operated pumps must be lubricated.
Wilden suggests an arctic weight oil (ISO grade 15).
CAUTION: When choosing pump materials, be sure to
check the temperature limits for all wetted components.
Example: Viton®has a maximum limit of 176.7°C (350°F) but
polypropylene has a maximum limit of only 79°C (175°F).
WARNING: Tighten all clamp bands prior to installation.
Fixing bolts may loosen during transportation.
CAUTION: Verify the chemical compatibility of the process
and cleaning fluid to the pump’s component materials in the
Chemical Resistance Guide (see E4).
CAUTION: Only explosion proof (NEMA 7) solenoid valves
should be used in areas where explosion proof equipment
is required.
Accu-Flo™ Model Available
Section 1
DIMENSIONAL DRAWING
DIMENSIONS
ITEM METRIC (mm) STANDARD (inch)
A 950 37.4
B 119 4.7
C 680 26.8
D 826 32.5
E 330 13.0
F 439 17.3
G 155 6.1
H 168 6.6
J 424 16.7
DIMENSIONS
ITEM METRIC (mm) STANDARD (inch)
K 333 13.1
L 279 11.0
M 455 17.9
N 376 14.8
P 15 DIA. .6 DIA.
R 231 9.1
S 191 7.5
T 18 DIA. .7 DIA.
Rev. B

2
WILDEN PUMP & ENGINEERING, LLC WIL-10280-E-04
The Model T20 has a 102 mm (4") inlet and 102 mm (4")
outlet and is designed for flows to 1041 lpm (275 gpm).
The T20 pump is manufactured with wetted parts of Cast
Iron. The center block of the T20 is constructed of die cast
aluminum. A variety of diaphragms, valve balls, and o-rings
are available to satisfy temperature, chemical compatibility,
abrasion and flex concerns.
The suction pipe size should be at least 102 mm (4") diam-
eter or larger if highly viscous material is being pumped. The
suction hose must be non-collapsible, reinforced type as the
T20 is capable of pulling a high vacuum. Discharge piping
should be at least 102 mm (4"); larger diameter can be used
to reduce friction losses. It is critical that all fittings and con-
nections are airtight or a reduction or loss of pump suction
capability will result.
The T20 can be used in submersible applications only when
both wetted and non-wetted portions are compatible with
the material being pumped. If the pump is to be used in a
submersible application, a hose should be attached to the
pump’s air exhaust and the exhaust air piped above the liq-
uid level.
If the pump is to be used in a self-priming application, be
sure that all connections are airtight and that the suction lift
is within the pump’s ability. Note: Materials of construction
and elastomer material have an effect on suction lift param-
eters. See pump performance data.
Pumps in service with a positive suction head are most
efficient when inlet pressure is limited to 0.5–0.7 bar (7–10
psig). Premature diaphragm failure may occur if positive
suction is 0.8 bar (11 psig) and higher.
THE MODEL T20 WILL PASS 35 mm (1-3/8") SOLIDS.
WHENEVER THE POSSIBILITY EXISTS THAT LARGER
SOLID OBJECTS MAY BE SUCKED INTO THE PUMP, A
STRAINER SHOULD BE USED ON THE SUCTION LINE.
CAUTION: DO NOT EXCEED 8.6 BAR (125 PSIG) AIR
SUPPLY PRESSURE.
BLOW OUT AIR LINE FOR 10 TO 20 SECONDS BEFORE
ATTACHING TO PUMP TO MAKE SURE ALL PIPE LINE
DEBRIS IS CLEAR. ALWAYS USE AN IN-LINE FILTER.
PUMPS SHOULD BE THOROUGHLY FLUSHED WITH
WATER BEFORE INSTALLING INTO PROCESS LINES. FDA
AND USDA APPROVED PUMPS SHOULD BE CLEANED
AND/OR SANITIZED BEFORE BEING USED ON EDIBLE
PRODUCTS.
Height...........................................826 mm (32.5")
Width............................................940 mm (37.0")
Depth ...........................................330 mm (13.0")
Est. Ship Weight............ Cast Iron 231 kg (500 lbs)
Air Inlet.............................................19 mm (3/4")
Inlet...................................................102 mm (4")
Outlet ................................................102 mm (4")
Suction Lift .................................. 12' Dry (3.66 m)
30' Wet (9.14 m)
Displacement per Stroke ............1.22 gal. (4.62 l)1
Max. Flow Rate......................1041 lpm (275 gpm)
Max. Size Solids ........................... 35 mm (1-3/8")
Example: To pump 140 gpm against a discharge
head of 20 psig requires 40 psig and 75 scfm air
consumption. (See dot on curve.)
1Displacement per stroke was calculated at 70 psig
air inlet pressure against a 30 psig head pressure.
Volumes indicated on chart were determined by actually pumping water.
For optimum life and performance, pumps should be specified so that daily operation param-
eters will fall in the center of the pump performance curve.
Water Discharge Flow Rates
T20 Metal Food Grade/Polyurethane-Fitted
Water Discharge Flow Rates
T20 Metal Wil-Flex™/Polyurethane-Fitted
Water Discharge Flow Rates
T20 Metal Viton®/PTFE-Fitted
Section 2
PERFORMANCE
Section 3 INSTALLATION
T20 METAL
RUBBER-FITTED

3WILDEN PUMP & ENGINEERING, LLCWIL-10280-E-04
INSTALLATION: Months of careful planning, study,
and selection efforts can result in unsatisfactory pump
performance if installation details are left to chance.
Premature failure and long term dissatisfaction can be
avoided if reasonable care is exercised throughout the
installation process.
LOCATION: Noise, safety, and other logistical factors usually
dictate that “utility” equipment be situated away from
the production floor. Multiple installations with conflicting
requirements can result in congestion of utility areas, leaving
few choices for siting of additional pumps.
Within the framework of these and other existing conditions,
every pump should be located in such a way that four
key factors are balanced against each other to maximum
advantage.
1. ACCESS: First of all, the location should be accessible.
If it’s easy to reach the pump, maintenance personnel will
have an easier time carrying out routine inspections and
adjustments. Should major repairs become necessary, ease
of access can play a key role in speeding the repair process
and reducing total downtime.
2. AIR SUPPLY: Every pump location should have an air line
large enough to supply the volume of air necessary to achieve
the desired pumping rate (see pump performance chart). Use
air pressure up to a maximum of 125 psig depending upon
pumping requirements.
For best results, the pumps should use an air filter, regulator,
and lubricator system. The use of an air filter before the pump
will ensure that the majority of any pipeline contaminants
will be eliminated. The use of a lubricant, suitable for the
application, helps perform a number of functions. Lubricants
reduce friction to minimize required shifting forces and
reduce wear. Lubricants provide a protective coating
against some forms of corrosion and contaminants. Wilden
suggests an oil with arctic characteristics (ISO 15-5Wt.)
This oil is chemically compatible with the center block
Glyd™ rings and has a low pour point to guard against
problems associated with low temperatures. The amount
of lubrication required is directly related to the amount of oil
introduced from the factory air system. We therefore suggest
that the lowest setting on the lubricator be utilized and then
increased as necessary.
Pump discharge rate can be controlled by limiting the volume
and/or pressure of the air supply to the pump. The use of a
needle valve installed at the air inlet to the pump is suggested
for this purpose. Pump discharge rate can also be controlled
by installing a valve in the discharge line of the pump when
the need to control the pump from a remote location exists.
When the pump discharge pressure equals or exceeds the air
supply pressure, the pump will stop; no bypass or pressure
relief valve is needed, and pump damage will not occur.
When operation is controlled by a solenoid valve in the air
line, a three-way valve should be used. Pumping volume can
be set by counting the number of strokes per minute.
A muffler installed on the the pump’s air exhaust will give
quiet exhaust. Sound levels are reduced below OSHA
specifications using a Wilden muffler.
3. ELEVATION: Selecting a site that is well within the pump’s
suction lift capability will assure that loss-of-prime troubles
will be eliminated. In addition, pump efficiency can be
adversely affected if proper attention is not given to elevation
(see pump performance chart).
4. PIPING: Final determination of the pump site should
not be made until the piping problems of each possible
location have been evaluated. The impact of current and
future installations should be considered ahead of time to
make sure that inadvertent restrictions are not created for
any remaining sites.
The best choice possible will be a site involving the shortest
and the straightest hook-up of suction and discharge
piping. Unnecessary elbows, bends, and fittings should be
avoided. Pipe sizes should be selected so as to keep friction
losses within practical limits. All piping should be supported
independently of the pump. In addition, it should line up
without placing stress on the pump fittings.
Expansion joints can be installed to aid in absorbing the forces
created by the natural reciprocating action of the pump. If the
pump is to be bolted down to a solid foundation, a mounting
pad placed between the pump and foundation will assist in
minimizing pump vibration. Flexible connections between
the pump and rigid piping will also assist in minimizing
pump vibration. If quick-closing valves are installed at any
point in the discharge system, or if pulsation within a system
becomes a problem, a surge suppressor should be installed
to protect the pump, piping and gauges from surges and
water hammer.
When pumps are installed in applications involving flooded
suction or suction head pressures, a gate valve should be
installed in the suction line to permit closing of the line for
pump service.
INSPECTIONS: Periodic inspections have been found to
offer the best means for preventing unscheduled pump
downtime.
Individuals responsible for checking and maintaining
lubrication levels in the pumps should also check for any
abnormal noise or leakage. Personnel familiar with the
pumps’ construction and service should be informed of any
abnormalities that are detected.
RECORDS: When service is required, a record should be
made of all necessary repairs and replacements. Over a
period of time, such records can become a valuable tool for
predicting and preventing future maintenance problems and
unscheduled downtime. In addition, accurate records make
it possible to identify pumps that are poorly suited to their
applications.
Section 4
SUGGESTED OPERATION & MAINTENANCE

4
WILDEN PUMP & ENGINEERING, LLC WIL-10280-E-04
Pump will not run or runs slowly.
1. Check air inlet screen and air filter for debris.
2. Check for sticking air valve, flush air valve in solvent.
3. Check for worn out air valve. If piston face in air valve is
shiny instead of dull, air valve is probably worn beyond
working tolerances and must be replaced.
4. Check center block Glyd™ rings. If worn excessively,
they will not seal and air will simply flow through pump
and out air exhaust. Use only Wilden Glyd™ rings as
they are of special construction.
5. Check for rotating piston in air valve.
6. Check type of lubricant being used. A higher viscosity
oil than suggested may cause the piston to stick or run
erratically. Wilden suggests the use of a hydraulic oil
with arctic characteristics (ISO 15-5 wt.).
Pump runs but little or no product flows.
1. Check for pump cavitation; slow pump speed down to
match thickness of material being pumped.
2. Check for sticking ball check valves. If material being
pumped is not compatible with pump elastomers,
swelling may occur. Replace ball check valves and o-
rings with proper elastomers.
3. Check to make sure all suction connections are air tight,
especially clamp bands around intake balls.
Pump air valve freezes.
Check for excessive moisture in compressed air. Either install
dryer or hot air generator for compressed air.
Air bubbles in pump discharge.
1. Check for ruptured diaphragm.
2. Check tightness of clamp bands, especially at intake
manifold.
Product comes out air exhaust.
1. Check for diaphragm rupture.
2. Check tightness of piston plates to shaft.
Valve ball rattling inside pump housing.
1. Create a suction lift allowing a positive seating action.
2. Create a head or discharge for positive seating action.
CAUTION: Before any maintenance or repair is attempted,
the compressed air line to the pump should be disconnected
and all air pressure allowed to bleed from pump. Disconnect
all intake, discharge and air lines.
The T20 has a 102 mm (4") inlet and 102 mm (4") outlet and is
designed for flows up to 300 gpm. Its air distribution system
is based upon design simplicity and proven efficiency. The
model T20 is available in cast iron.
NOTE: Before starting disassembly, mark a line from each
liquid chamber to its corresponding air chamber, as well as a
line from the liquid chamber to its corresponding discharge
elbow and ball pot. These lines will assist in proper alignment
during reassembly.
Section 5
TROUBLESHOOTING
Section 6 DISASSEMBLY/REASSEMBLY INSTRUCTIONS

5WILDEN PUMP & ENGINEERING, LLCWIL-10280-E-04
Step 1 DISASSEMBLY/REASSEMBLY INSTRUCTIONS
Start disassembly by removing the wing nuts from the ball pots. This allows the ball pot cover to be removed,
exposing the discharge or inlet ball valves and ball pot lid o-rings for inspection. (See Figures 1A, 1B.)
Step 2
Remove clamp bands around the bottom of discharge ball pots. (See Figure 2A). It is now possible, with assis-
tance, to remove the discharge manifold assembly from the main body of the ump. (See Figure 2B.) This allows
for inspection of the valve seats.
Step 3
Disconnect clamp bands from around the bottom of the inlet ball pots. (See Figure 3A.) It is now possible, with
assistance, to remove the main body of the pump. (See Figure 3B.)
The pump is now in three sections: 1. Inlet housing 2. Center section housing. 3. Discharge housing
Figure 1A Figure 1B
Figure 2A Figure 2B
Figure 3A Figure 3B

6
WILDEN PUMP & ENGINEERING, LLC WIL-10280-E-04
DISASSEMBLY
Loosen clamp band around inlet elbow. (See
Figure 1A.) Remove the clamp band while
supporting the elbow. This step will allow for
inspection of the manifold gasket between the
elbows and inlet-tee. (See Figure 1B.) Repeat
this step for removal of opposite elbow.
REASSEMBLY
To reassemble, set the tee-section on end.
Stretch the gasket lip around the sealing surface
of the tee-section. (See Figure 2A.) Align the
inlet elbow and replace the clamp band. To reas-
semble the opposite elbow, balance the assem-
bly on the attached elbow as shown in Figure
2B. This will allow you to look down the length
of the manifold giving you the proper perspec-
tive to align the elbow not yet attached. Align the
second inlet elbow and replace the clamp band.
Figure 1A
Figure 2A
Figure 1B
NOTE:
To insure that
the elbows
ar on the
same level
plane, rest
the manifold
on its feet
and place a
straight edge
diagonally
across the
full length
of the mani-
fold resting
the straight edge on the sealing surface of the
elbows. When level tighten clamp bands.
DIASSEMBLY & REASSEMBLY OF INLET HOUSING
Figure 2B

7WILDEN PUMP & ENGINEERING, LLCWIL-10280-E-04
Step 1
Loosen clamp band around discharge elbow.
Remove the clamp band while supporting the
elbow. This step will allow for inspection of
the manifold gasket between elbows and water
chamber. (See Figure 1A.) Repeat this step for
removal of opposite elbow.
Figure 1A Figure 2B
Figure 2A
Step 2
Roll the center housing slightly to achieve better
access to the clamp band bolts. (See Figure 2A.)
Remove the clamp bands connecting the ball
pots to the air chamber. This procedure allows
inspection of the manifold gasket between the
ball pot and water chamber, as well as inspec-
tion of the ball seat found on the bottom side of
the ball pot. (See Figure 2B.)
NOTE: You may want to place blocks on each side of
the center section. This will prevent the center section
from rolling as the ball pots are being removed.
DIASSEMBLY & REASSEMBLY OF CENTER SECTION HOUSING
DISASSEMBLY
Step 3
After removing the ball pots set the center
section on end. Loosen and remove the clamp.
(See Figure 3A.) This allows for removal of the
water chamber. (See Figure 3B.)
With the center section still upright loosen and
remove the opposite clamp band. The center
section can now be lifted off of the water cham-
ber, exposing both diaphragms for inspection.
Figure 3A Figure 3B

8
WILDEN PUMP & ENGINEERING, LLC WIL-10280-E-04
Step 6
Gently turn the center section over onto the exposed end of the shaft. Gently push down on the center section
which will force the shaft through the center block. It will then be possible to grip the edges of the diaphragm and
pull the remainder of the shaft through the center block. Unscrew the outer piston and lift the assembly off the
shaft. If needed, a vise with wood blocks is the suggested method of securing shaft while removing the second
outer piston. It is important not to score or mark the chrome-plated shaft.
Step 7
To remove the air chamber from the center block simply remove the four flat head screws. This will expose the
center block for inspection. Disassembly of the center block and shaft/piston units are shown below.
Step 4
Place the center section as shown in Figure 4A.
Place a wrench over the nut at the center of each
outer piston, and loosen the outer piston plate.
Step 5
Again, place the center section upright so that the diaphragm in the full stroke position is exposed. Using a
pry bar, turn the edge of the diaphragm up. (See Figure 5A.) It is now possible to remove the entire diaphragm
assembly by unscrewing the outer piston and lifting the assembly off the shaft. (Figure 5B.)
Figure 5A Figure 5B
Figure 4A
DIASSEMBLY & REASSEMBLY OF CENTER SECTION HOUSING

9WILDEN PUMP & ENGINEERING, LLCWIL-10280-E-04
Step 1
Prior to reassembly, remove Glyd™ rings from center
block bushing and flush the center block, removing
grit and contaminants. Install new Glyd™ rings in
center block. Reassemble air valve, center block and
air chambers per the torque specifications*.
Step 2
Pre-assemble the inner piston, diaphragm and outer
piston per the torque specifications*. Attach the pre-
assembled diaphragm configuration to either end
of the shaft. Lubricate the bushing with a 5W non-
synthetic, non-detergent oil so that the shaft will pass
through the Glyd™ rings. Insert the shaft firmly into
the bushing. Turn the center section over and push
the diaphragm from full stroke position to exhaust
position. This will expose the shaft so that the other
pre-assembled diaphragm configuration can be posi-
tioned. (See Figure 2A.)
*Refer to Section 8 for required torque specifications.
REASSEMBLY OF CENTER SECTION HOUSING
Figure 2A
Figure 2B
Step 3
Attach the other pre-assembled diaphragm configuration to the other end of the shaft. After installation of the
diaphragm, tighten the outer pistons by laying the assembly horizontally and tightening both outer pistons simulta-
neously per torque specification*. (See Figure 2A.)
Stand the center section upright and replace the water
chamber and clamp band. Tighten per the torque
specification*. (Note: Be sure that your marks on the
water and air chambers are properly aligned.) The
center section should then be turned over so that
the diaphragm can be pushed up with pry bars to full
stroke position. The opposing water chamber can now
be assembled. (See Figure 2B.)

10
WILDEN PUMP & ENGINEERING, LLC WIL-10280-E-04
Figure 4A Figure 5A
*Refer to Section 8 for required torque specifications.
Step 4
Return the pump to an upright position. (See Figure
4A.) Replace gaskets on both sealing surfaces of the
water chamber. Realign one discharge elbow and ball
pot. Replace the clamp bands and tighten per the
torque specification*.
Step 5
Flip the assembly over and stand the unit upright using
a block of wood to support the assembly. (See Figure
5A.) Replace the gaskets. Realign the discharge elbow
and ball pot.
REASSEMBLY OF CENTER SECTION HOUSING

11 WILDEN PUMP & ENGINEERING, LLCWIL-10280-E-04
REASSEMBLY
Step 1
To reassemble the discharge housing, set
the tee-section on end. Stretch the gasket lip
around the sealing surface of the tee-section.
(See Figure 1C.) Align the ball pot and replace the
clamp band (hand tighten only). To reassemble the
opposite ball pot, balance the discharge tee on the
attached ball pot as shown in Figure 1D. Align the
ball pot and attach the clamp band. (Hand tighten
only.)
NOTE: To insure that the ball pots are on the
same level plane, rest the manifold horizontally
and place a straight edge diagonally across the
full length of the manifold resting the straight edge
on the sealing surface of the ball pots. When level
tighten clamp bands per the torque specification*.
Step 1
Loosen clamp bands between ball pots and discharge tee. Remove the bands while supporting the tee-section.
This will allow for inspection of the seals between the ball pots and discharge tee-section (see Figure 1A) as well
as inspection of the ball seat found on the bottom side of the ball pot. (See Figure 1B.)
*Refer to Section 8 for required torque specifications.
Figure 1A Figure 1B
Figure 1C Figure 1D
DIASSEMBLY & REASSEMBLY OF DISCHARGE HOUSING
DISASSEMBLY

12
WILDEN PUMP & ENGINEERING, LLC WIL-10280-E-04
Step 1
With assistance, place the center section housing onto the inlet manifold. Replace clamp bands around the inlet
elbows and ball pots and tighten per the torque specification*.
Step 2
With assistance, place the discharge assembly onto the discharge elbows. Replace the clamp bands around the
discharge elbows and ball pots and tighten per the torque specification*.
Step 3
Place the valve balls into the ball pots, replace the ball pot plate o-ring and the ball pot plate. Hand-tighten the
wing nuts.
REASSEMBLY OF PUMP BODY

13 WILDEN PUMP & ENGINEERING, LLCWIL-10280-E-04
*Refer to Section 8 for required torque specifications.
Small nicks can usually be dressed out and the piston
returned to service. Inspect the cylinder end caps. Make sure
that the guide pin is straight and smooth or the piston will not
move freely in the cylinder. Clean out anti-centering pin holes
located on each side of the piston. Pin holes are located on
each side of the annular groove on the top of the piston and
travel to each end. New o-rings should be installed on the
end caps, assuring that proper alignment of the piston and
cylinder ports is maintained. Reinstall air valve to center block
of pump.
GLYD™ RING REPLACEMENT
When the Glyd™ rings become worn, they will no longer
seal and must be replaced. Due to the design characteristics
of Glyd™ rings, it is suggested you use the Ringer™ seal
installation kit when replacing Glyd™ rings (P/N 15-9341-99).
Consult EOM-Ringer for installation instructions.
CENTER BLOCK ASSEMBLY
The pump’s center block consists of a molded housing with
a cast-in-bronze bushing. The bushing has eleven grooves
cut on the inside diameter. There are seven Glyd™ rings that
fit in these grooves. Since these Glyd™ rings form a part of
the shifting function of the pump, it is necessary that they be
located in the proper grooves. When bushing wear becomes
excessive, a new center block must be used.
Figure A
The air valve assembly consists of both the air valve body
and piston and the center block. The unique design of the air
valve relies on differential pressure to effect the diaphragm
shift. It is reliable and simple to maintain. The bushing in the
center block, along with the diaphragm shaft, provides the
“trigger” to tell the air valve to shift. The following procedure
will ensure that the air valve on your Wilden pump will
provide long trouble-free service.
AIR VALVE BODY AND PISTON
ASSEMBLY AND DISASSEMBLY
The air valve body and piston can be disconnected from
the pump by removing the four socket-head cap screws
which attach it to the center block. The piston should
move freely and the ports in the piston should line up with
the ports on the face of the air valve body. The piston
should also appear to be a dull dark gray in color. If the
piston appears to be a shiny aluminum color, the air valve
is probably worn beyond working tolerances and should
be replaced.
If the piston does not move freely in the air valve, the
entire air valve should be immersed in a cleaning solution
(NOTE: Do not force the piston by inserting a metal
object.) This soaking should remove any accumulation of
sludge and grit which is preventing the air valve piston
from moving freely. Also, remove and clean the air valve
screen. If the air valve piston does not move freely after
the above cleaning, the air valve should be disassembled
as follows: remove the snap ring from the top end of the
air valve cylinder and apply an air jet to the 3/16-inch hole
in the opposite end of the air valve face. CAUTION: The
air valve end cap may come out with considerable force.
Hand protection such as a padded glove or rag should
be used to capture the end cap. Inspect the piston and
cylinder bore for nicks and scoring.
Section 6A
DIASSEMBLY & REASSEMBLY OF AIR VALVE/CENTER BLOCK
Figure B

14
WILDEN PUMP & ENGINEERING, LLC WIL-10280-E-04
Ultra-Flex™ Assembly
Standard
Assembly
6
3
4
5
13 15
16
46 17
47 15
44
43
45 40
42
41
21
11
8 9
7
10
14
12
19
21
32
34
35
33
23
18
17
17
23
46
38
30
28
31
29
27
39
37
25
26
36
24
20
Section 8 exploded view & parts listing
Section 7
EXPLODED VIEW & PARTS LISTING
T20 ORIGINALTM METAL EXPLODED VIEW

15 WILDEN PUMP & ENGINEERING, LLCWIL-10280-E-04
ITEM DESCRIPTION QTY.
T20/WWWAD
P/N
1 Air Valve Assembly with Oil Bottle 1 15-2080-07-225
2 Air Valve Screen 1 08-2500-07
3 Air Valve End Cap with Guide 1 15-2300-23
4 Air Valve End Cap without Guide 1 15-2330-23
5 Air Valve Snap Ring 2 15-2650-03
6 Air Valve Cap O-Ring 2 15-2390-52
7 Oil Bottle 1 15-2850-01
8 Plug 1 15-7000-07
9 Capillary Rod 1 15-2900-99
10 Air Valve Gasket — Buna-N 1 15-2600-52
11 Air Valve Screws 4 08-6000-08
12 Center Block 1 15-3100-01-225
13 Center Block Glyd™ Ring 7 15-3210-55-225
14 Block Gasket — Buna-N 2 15-3520-52
15 Shaft 1 20-3800-09-07
Shaft, Ultra-Flex™ 1 20-3830-09-07
16 Piston, Outer 2 20-4550-02
Piston, Outer, Ultra-Flex™ 2 20-4560-02
17 Piston, Inner 2 15-3700-01
Piston, Inner, Ultra-Flex™ 2 15-3760-08
18 Washer, Inner Piston Back-Up 2 15-6850-08
19 Piston Assembly — Bolt & Washer 12 15-6130-08/
15-6720-08
20 Air Chamber 2 15-3650-02
21 Air Chamber — Screw 4 15-6200-08
22 Air Chamber — Nut 4 08-6550-08
23 Liquid Chamber 2 20-5000-02
24 Tee Manifold 2 20-5160-02
25 Manifold Gaskets 8 *
26 Elbow 4 20-5220-02
27 Pot 4 20-5460-02
28 Plate 4 20-5480-02
29 Plate O-Ring 4 *
30 Wing Nut 8 20-6690-02
31 Wing Nut Stud 8 20-6160-08
32 Foot 2 20-5540-02
33 U-Bolt 2 20-6300-08
34 U-Bolt Nut 4 15-6420-08
35 U-Bolt Lock Washer 4 20-6750-08
36 Pipe Plug — 3/4" 4 20-7010-07
37 Large Clamp Band Assy. 2 15-7300-03
38 Large Carriage Bolt 4 15-6120-03
39 Large Hex Nut 4 15-6420-03
40 Medium Clamp Band Assy. 4 20-7200-03
41 Small Clamp Band18 20-7100-03
42 Medium Carriage Bolt 24 04-6070-03
43 Medium Hex Nut 24 08-6400-03
44 Valve Ball 4 *
45 Valve Ball Seat 4 *
46 Diaphragm 2 *
47 Spacer, Ultra-Flex™ 2 15-6850-08
Muffler (Not shown) 1 15-3510-99
EXPLODED VIEW & PARTS LISTING
T20 ORIGINALTM METAL PARTS LISTING
1Small clamp band uses medium carriage bolt (04-6070-03)
and medium hex-nut (08-6400-03).
*Refer to corresponding elastomer chart in Section 8.
All boldface items are primary wear parts.

16
WILDEN PUMP & ENGINEERING, LLC WIL-10280-E-04
TEMPERATURE LIMITS:
Neoprene 0°F to 200°F –17.8°C to 93.3°C
Buna-N +10°F to +180°F –12.2°C to 82.2°C
EPDM –60°F to 280°F –51.1°C to 137.8°C
Viton®–40°F to +350°F –40°C to 176.7°C
Wil-Flex™ –40°F to +225°F –40°C to 107.2°C
Polyurethane 10°F to 150°F 12.2°C to 65.6°C
Saniflex™ –20°F to 220°F –28.9°C to 104.4°C
PTFE 40°F to +220°F 4.4°C to 104.4°C
Fluoro-Seal™ –40°F to +450°F –40°C to 232°C
CAUTION: When choosing pump materials, be sure to check the
temperature limits for all wetted components. Example: Viton®has a
maximum limit of 176.7°C (350°F) but polypropylene has a maximum
limit of only 79°C (175°F).
CAUTION: Maximum temperature limits are based upon mechanical
stress only. Certain chemicals will significantly reduce maximum safe
operating temperatures. Consult engineering guide for chemical
compatibility and temperature limits.
ELASTOMER OPTIONS
MATERIAL
DIAPHRAGM (2)
P/N
ULTRA-FLEX®
DIAPHRAGM (2)
P/N VALVE BALL (4) P/N VALVE SEAT (4) P/N
PLATE O-RING (4)
P/N
MANIFOLD
GASKET (8) P/N
Polyurethane 15-1010-50 N/A 20-1080-50 20-1120-50 N/A N/A
Neoprene N/A 15-1020-51 N/A N/A N/A N/A
Buna-N 15-1010-52 15-1020-52 N/A N/A N/A N/A
Viton®15-1010-53 15-1020-53 N/A 20-1120-53 20-1250-53 20-1400-53
EPDM 15-1010-54 15-1020-54 N/A N/A N/A 20-1400-54
PTFE N/A N/A 20-1080-55 N/A N/A N/A
Saniflex™ 15-1010-56 N/A N/A N/A N/A N/A
Wil-Flex™15-1010-58 N/A N/A N/A N/A N/A
TORQUE SPECIFICATIONS
ITEM # DESCRIPTION OF PART MAXIMUM TORQUE
1 Air Valve 9.0 N•m (80 in-lbs)
2 Outer Piston 135.6 N•m (78 ft-lbs)
3 2C Ring & Piston 24.4 N•m (18 ft-lbs)
4 Center Block Assembly 31.2 N•m (23 ft-lbs)
5 Large Clamp Bands 61.0 N•m (45 ft-lbs)
6 Small & Medium Clamp Bands 17.6 N•m (13 ft-lbs)
7 Wing Nut —
8 U-Bolt 44.7 N•m (33 ft-lbs)
9 Prime Plug 105.8 N•m (78 ft-lbs)
Section 8
ELASTOMER OPTIONS/TORQUE SPECIFICATIONS

Item # Serial #
Company Where Purchased
Company Name
Industry
Name Title
Street Address
City State Postal Code Country
Telephone Fax E-mail Web Address
Number of pumps in facility? Number of Wilden pumps?
Types of pumps in facility (check all that apply): Diaphragm Centrifugal Gear Submersible Lobe
Other
Media being pumped?
How did you hear of Wilden Pump? Trade Journal Trade Show Internet/E-mail Distributor
Other
PUMP INFORMATION
PLEASE PRINT OR TYPE AND FAX TO WILDEN
YOUR INFORMATION
ONCE COMPLETE, FAX TO [phone]
NOTE: WARRANTY VOID IF PAGE IS NOT FAXED TO WILDEN
WILDEN PUMP & ENGINEERING, LLC
WARRANTY
Each and every product manufactured by Wilden Pump and Engineering, LLC is built to meet the highest
standards of quality. Every pump is functionally tested to insure integrity of operation.
Wilden Pump and Engineering, LLC warrants that pumps, accessories and parts manufactured or supplied by
it to be free from defects in material and workmanship for a period of five (5) years from date of installation or
six (6) years from date of manufacture, whichever comes first. Failure due to normal wear, misapplication, or
abuse is, of course, excluded from this warranty.
Since the use of Wilden pumps and parts is beyond our control, we cannot guarantee the suitability of any pump
or part for a particular application and Wilden Pump and Engineering, LLC shall not be liable for any consequential
damage or expense arising from the use or misuse of its products on any application. Responsibility is limited
solely to replacement or repair of defective Wilden pumps and parts.
All decisions as to the cause of failure are the sole determination of Wilden Pump and Engineering, LLC.
Prior approval must be obtained from Wilden for return of any items for warranty consideration and must be
accompanied by the appropriate MSDS for the product(s) involved. A Return Goods Tag, obtained from an
authorized Wilden distributor, must be included with the items which must be shipped freight prepaid.
The foregoing warranty is exclusive and in lieu of all other warranties expressed or implied (whether written or oral)
including all implied warranties of merchantability and fitness for any particular purpose. No distributor or other
person is authorized to assume any liability or obligation for Wilden Pump and Engineering, LLC other than expressly
provided herein.