Dover Wilden Advanced Series Instruction Manual

H400S
W IL-11110 - E - 0 4
R EP L A CE S W IL-11110 - E - 0 3
EOM
Engineering
Operation &
Maintenance
Advanced™Series METAL Pumps
Advance your process

TABLE OF CONTENTS
SECTION 1 CAUTIONS—READ FIRST! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
SECTION 2 WILDEN PUMP DESIGNATION SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
SECTION 3 HOW IT WORKS—PUMP & AIR DISTRIBUTION SYSTEM . . . . . . . . . . . . . . . .3
SECTION 4 DIMENSIONAL DRAWINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
SECTION 5 PERFORMANCE
A. H400S Performance Curves
TPE-Fitted Aluminum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
TPE-Fitted Stainless Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
B. H400S Suction Lift Curves
TPE-Fitted Aluminum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
TPE-Fitted Stainless Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
SECTION 6 SUGGESTED INSTALLATION, OPERATION & TROUBLESHOOTING. . . . . . . .8
SECTION 7 ASSEMBLY / DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
SECTION 8 EXPLODED VIEW & PARTS LISTING
TPE-Fitted Aluminum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
TPE-Fitted Stainless Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

CAUTION: Do not apply compressed air to the
exhaust port — pump will not function.
CAUTION: Do not over-lubricate air supply —
excesslubricationwill reducepumpperformance.
Pump is pre-lubed.
TEMPERATURE LIMITS:
Neoprene –17.7°C to 93.3°C 0°F to 200°F
Buna-N –12.2°C to 82.2°C 10°F to 180°F
EPDM –51.1°C to 137.8°C –60°F to 280°F
Viton®–40°C to 176.7°C –40°F to 350°F
Saniflex™ –28.9°C to 104.4°C –20°F to 220°F
Wil-Flex™ -40ºC to 107.2ºC –40ºF to 225ºF
Polytetrafluoroethylene (PTFE)
4.4°C to 104.4°C 40°F to 220°F
Polyurethane –12.2°C to 65.6°C 10°F to 150°F
Tetra-Flex™ PTFE w/Neoprene Backed
4.4°C to 107.2°C 40°F to 225°F
Tetra-Flex™ PTFE w/EPDM Backed
-10°C to 137°C 14°F to 280°F
NOTE: Not all materials are available for all
models. Refer to Section 2 for material options
for your pump.
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 Chemical
Resistance Guide (E4) for chemical compatibility
and temperature limits.
WARNING: Prevention of static sparking — If
static sparking occurs, fire or explosion could
result. Pump, valves, and containers must be
grounded to a proper grounding point when
handling flammable fluids and whenever
discharge of static electricity is a hazard.
CAUTION: Do not exceed 8.6 bar (125 psig) air
supply pressure.
CAUTION: All piping, valves, gauges and other
components installed on the liquid discharge must
have a minimum pressure rating of 20.7 bar (300 psig).
CAUTION: The discharge pressure generated by
this pump is 2X the inlet pressure supplied.
CAUTION: The process fluid and cleaning fluids
must be chemically compatible with all wetted
pump components. Consult Chemical Resistance
Guide (E4).
CAUTION: Do not exceed 82°C (180°F) air inlet
temperature for Pro-Flo V™ models.
CAUTION: Pumps should be thoroughly flushed
before installing into process lines. FDA and
USDA approved pumps should be cleaned and/
or sanitized before being used.
CAUTION: Always wear safety glasses when
operating pump. If diaphragm rupture occurs,
material being pumped may be forced out air
exhaust.
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. Drain the pump
by turning it upside down and allowing any fluid
to flow into a suitable container.
CAUTION: Blow out air line for 10 to 20 seconds
before attaching to pump to make sure all pipeline
debris is clear. Use an in-line air filter. A 5µ (micron)
air filter is recommended.
NOTE: When installing PTFE diaphragms, it is
important to tighten outer pistons simultaneously
(turning in opposite directions) to ensure tight fit.
(See torque specifications in Section 7.)
NOTE: Cast Iron PTFE-fitted pumps come
standard from the factory with expanded PTFE
gaskets installed in the diaphragm bead of the
liquid chamber. PTFE gaskets cannot be re-used.
Consult PS-TG for installation instructions during
reassembly.
NOTE: Before starting disassembly, mark a line
from each liquid chamber to its corresponding air
chamber. This line will assist in proper alignment
during reassembly.
CAUTION: Pro-Flo®pumps cannot be used in
submersible applications. Pro-Flo V™ is available
inbothsubmersible andnon-submersibleoptions.
Do not use non-submersible Pro-Flo V™ models
in submersible applications. Turbo-Flo®pumps
can also be used in submersible applications.
CAUTION: Tighten all hardware prior to installation.
WIL-11110 - E- 04 1 WILDEN PUMP & ENGINEERING, LLC
Section 1
CAUTIONS—READ FIRST!

WILDEN PUMP & ENGINEERING, LLC 2 WIL-11110 - E- 04
Section 2
WILDEN PUMP DESIGNATION SYSTEM
H400S METAL
38 mm (1-1/2") Pump
Maximum Flow Rate:
242 lpm (64 gpm)
LEGEND
H400S /XXXXX/XX/XX/XXX/ XXX
O-RINGS
MODEL VALVE SEAT
VALVE BALLS
DIAPHRAGMS
AIR VALVE
CENTER BLOCK
AIR CHAMBERS
WETTED PARTS & OUTER PISTON
SPECIALTY
CODE
(if applicable)
MATERIAL CODES
MODEL
H400S = HIGH PRESSURE
SIMPLEX
WETTED PARTS & OUTER
PISTONS
AA = ALUMINUM/ ALUMINUM
SS = STAINLESS STEEL/
STAINLESS STEEL
AIR CHAMBERS
A = ALUMINUM
CENTER BLOCK
A = ALUMINUM
AIR VALVE
A = ALUMINUM
DIAPHRAGMS
WFS = WIL-FLEX™
[Santoprene®(Orange
Dot)]
VALVE BALL
WF= WIL-FLEX™
[Santoprene®(Orange Dot)]
VALVE SEAT
A = ALUMINUM
S = STAINLESS STEEL
VALVE SEAT O-RING
TF = PTFE (White)
NOTE: MOST ELASTOMERIC MATERIALS USE COLORED DOTS FOR IDENTIFICATION.
NOTE: Not all models are available with all material options.
Nordel®and Viton®are registered trademarks of DuPont Dow Elastomers.
Teflon®is a registered trademark of DuPont.
Halar®is a registered trademark of Solvay.
SPECIALTY CODES
0245 Reverse manifolds
0247 Discharge & inlet manifold facing exhaust
0250 Discharge manifold facing air inlet
0320 Submersible center block
0504 DIN flange

WIL-11110 - E- 04 3 WILDEN PUMP & ENGINEERING, LLC
Section 3
HOW IT WORKS—PUMP
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 When air pressure is supplied
to the pump, the air valve directs pressure
to the back side of diaphragm A. The
compressed air moves the diaphragm
away from the center section of the pump.
The opposite diaphragm is pulled in by
the shaft connected to the pressurized
diaphragm. Diaphragm B is on its suction
stroke; air behind the diaphragm has been
forced out to the atmosphere through
the exhaust port. The movement of
diaphragm B towards the center section
of the pump creates a vacuum within
chamber B. Atmospheric pressure forces
fluid into the inlet manifold forcing the
inlet valve ball off of its seat. Liquid is
free to move past the inlet valve ball and
fill the liquid chamber (see shaded area).
FIGURE 2 Once the shaft has reached the
end of its stroke, the air valve redirects
pressurized air to the back side of
diaphragm B. This pressurized air is also
directed to the opposite side of diaphragm
A through a passageway that is routed
through the common shaft and outer piston.
The pressurized air forces diaphragm B
away from the center section while also
pushing diaphragm A to the center section.
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 of its seat, forcing
fluid to flow through the pump discharge.
The pressure on diaphragm A creates a
force on the shaft that is combined with
the pressure from diaphragm B. This total
load is transferred to the liquid creating a
liquid pressure that is 2X greater than the
supplied air pressure.
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
condition of the application.
The Pro-Flo V™p a t e n ted ai r dis t rib u t ion s y s t e m inc orp o r a t e s t w o
moving parts: the air valve spool and the pilot spool. The heart
of the system is the air valve. This valve design incorporates an
unbalanced spool. The smaller end of the spool is pressurized
continuously, while the large end is alternately pressurized,
then exhausted, to move the spool. The air valve spool directs
pressurized air to one air chamber while exhausting the other.
The air causes the main shaft/diaphragm assembly to shift to
one side — discharging liquid on that side and pulling liquid in
on the other side. When the shaft reaches the end of its stroke,
the inner piston actuates the pilot spool, which pressurizes and
exhausts the large end of the air valve spool. The repositioning
of the air valve spool routes the air to the other air chamber.
HOW IT WORKS—AIR DISTRIBUTION SYSTEM

WILDEN PUMP & ENGINEERING, LLC 4 WIL-11110 - E- 04
Section 4
DIMENSIONAL DRAWINGS
H400S Aluminum DIMENSIONS
ITEM METRIC (mm) STANDARD (inch)
A 345 13.6
B 79 3.1
C 318 12.5
D 528 20.8
E 605 23.8
F 127 5.0
G 323 12.7
H 48 1.9
J 132 5.2
K 310 12.2
L 518 20.4
M 241 9.5
N 203 8.0
P 152 6.0
R 170 6.7
S 10 0.4
DIN (mm) ANSI (inch)
T 150 dia. 6.1 dia.
U 110 dia. 4.5 dia.
V 18 dia. 0.9 dia.
H400S Stainless Steel DIMENSIONS
ITEM METRIC (mm) STANDARD (inch)
A 384 15.1
B 89 3.5
C 277 10.9
D 528 20.8
E 279 11.0
F 48 1.9
G 132 5.2
H 310 12.2
J 508 20.0
K 84 3.3
L 274 10.8
M 224 8.8
N 178 7.0
P 203 8.0
R 10 0.4
DIN (mm) ANSI (inch)
S 150 dia. 6.1 dia.
T 110 dia. 4.5 dia.
U 18 dia. 0.9 dia.

WIL-11110 - E- 04 5 WILDEN PUMP & ENGINEERING, LLC
A. P400 Aluminum performance
Curves
Flow rates indicated on chart were determined by pumping water.
For optimum life and performance, pumps should be specified so that daily operation
parameters will fall in the center of the pump performance curve.
Air inlet pressure values are 50% of discharge pressure values shown on Y axis.
H400S ALUMINUM
TPE-FITTED
Section 5A
PERFORMANCE
Height .................................605 mm (23.8”)
Width ..................................345 mm (13.6”)
Depth .................................. 310 mm (12.2”)
Est. Ship Weight..Aluminum 27 kg (60 lbs)
Air Inlet ................................... 19 mm (3/4”)
Inlet ......................................38 mm (1-1/2”)
Outlet ...................................38 mm (1-1/2”)
Suction Lift ....................... 3.1 m Dry (10.1’)
9.3 m Wet (30.6’)
Max. Flow Rate .............. 242 lpm (64 gpm)
Max. Size Solids..................8.0 mm (5/16”)
Example:To pump 61 lpm (16 gpm) against
a discharge pressure head of 5.2 bar (75
psig) requires 4.1 bar (60 psig) and 60
Nm3/h (35 scfm) air consumption. (See
dot on chart.)
Caution: Do not exceed 8.6 bar (125 psig)
air supply pressure.
A. P400 Aluminum performance
Curves
H400S STAINLESS STEEL
TPE-FITTED
Height ................................. 528 mm (20.8")
Width .................................. 384 mm (15.1")
Depth ...................................310 mm (12.2")
Est. Ship Weight ......Stainless Steel 37 kg (82 lbs)
Air Inlet ....................................19 mm (3/4")
Inlet ...................................... 38 mm (1-1/2")
Outlet ................................... 38 mm (1-1/2")
Suction Lift ....................... 3.1 m Dry (10.2')
9.0 m Wet (29.5')
Max. Flow Rate .............. 186 lpm (49 gpm)
Max. Size Solids.................. 4.8 mm (3/16")
Example: To pump 61 lpm (16 gpm) against
a discharge pressure head of 5.2 bar
(75 psig) requires 3.8 bar (55 psig) and
81.5 Nm3/h (48 scfm) air consumption.
(See dot on chart.)
Caution: Do not exceed 8.6 bar (125 psig)
air supply pressure.
Flow rates indicated on chart were determined by pumping water.
For optimum life and performance, pumps should be specified so that daily operation
parameters will fall in the center of the pump performance curve.
Air inlet pressure values are 50% of discharge pressure values shown on Y axis.

WILDEN PUMP & ENGINEERING, LLC 6 WIL-11110 - E- 04
H400S METAL
Section 5B SUCTION LIFT CURVE
Suction lift curves are calibrated for pumps operating
at 305 m (1,000') above sea level. This chart is meant
to be a guide only. There are many variables which
can affect your pump’s operating characteristics. The
number of intake and discharge elbows, viscosity of
pumping fluid, elevation (atmospheric pressure) and
pipe friction loss all affect the amount of suction lift
your pump will attain.

NOTES
WIL-11110 - E- 04 7 WILDEN PUMP & ENGINEERING, LLC

WILDEN PUMP & ENGINEERING, LLC 8 WIL-11110 - E- 04
Section 6
SUGGESTED INSTALLATION
Section 6 Suggested
Wilden pumps are designed to meet the performance
requirements of even the most demanding pumping
applications. They have been designed and manufactured
to the highest standards and are available in a variety of
liquid path materials to meet your chemical resistance
needs. Refer to the performance section of this manual for
an in-depth analysis of the performance characteristics of
your pump. Wilden offers the widest variety of elastomer
options in the industry to satisfy temperature, chemical
compatibility, abrasion resistance and flex concerns.
The suction pipe size should be at least the equivalent or
larger than the diameter size of the suction inlet on your
Wilden pump. The suction hose must be non-collapsible,
reinforced type as these pumps are capable of pulling a high
vacuum. Discharge piping should also be the equivalent
or larger than the diameter of the pump discharge which
will help reduce friction losses. It is critical that all fittings
and connections are airtight or a reduction or loss of pump
suction capability will result.
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 where equipment will be situated on the production
floor. Multiple installations with conflicting requirements
can result in congestion of utility areas, leaving few choices
for additional pumps.
Within the framework of these and other existing conditions,
every pump should be located in such a way that six key
factors are balanced against each other to maximum
advantage.
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.
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. Use air pressure up to
a maximum of 8.6 bar (125 psig) depending on pumping
requirements.
For best results, the pumps should use a 5µ (micron) air
filter, needle valve and regulator. The use of an air filter
before the pump will ensure that the majority of any pipeline
contaminants will be eliminated.
SOLENOID OPERATION: When operation is controlled by a
solenoid valve in the air line, three-way valves should be
used. This valve allows trapped air between the valve and
the pump to bleed off which improves pump performance.
Pumping volume can be estimated by counting the number
of strokes per minute and then multiplying the figure by the
displacement per stroke.
MUFFLER: Sound levels are reduced below OSHA
specifications using the standard Wilden muffler. Other
mufflers can be used to further reduce sound levels, but
they usually reduce pump performance.
ELEVATION: Selecting a site that is well within the pump’s
dynamic lift capability will assure that loss-of-prime issues will
be eliminated. In addition, pump efficiency can be adversely
affected if proper attention is not given to site location.
PIPING: Final determination of the pump site should not be
made until the piping challenges 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 straightest hook-up of suction and discharge piping.
Unnecessary elbows, bends, and fittings should be avoided.
Pipe sizes should be selected to keep friction losses within
practical limits.All piping should be supported independently
of the pump. In addition, the piping should be aligned to
avoid placing stress on the pump fittings.
Flexible hose 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 location, a mounting
pad placed between the pump and the 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 (SD Equalizer®)
should be installed to protect the pump, piping and gauges
from surges and water hammer.
If the pump is to be used in a self-priming application, make
sure that all connections are airtight and that the suction lift is
within the model’s ability. Note: Materials of construction and
elastomer material have an effect on suction lift parameters.
Please refer to the performance section for specifics.
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.
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 0.7 bar (10 psig) and higher.
SUBMERSIBLE APPLICATIONS: Pro-Flo V™ pumps can be
used for submersible applications, when using the Pro-Flo
V™ submersible option. Turbo-Flo™ pumps can also be
used for submersible applications.
NOTE: Pro-Flo®and Accu-Flo™ pumps are not submersible.
ALL WILDEN PUMPS ARE CAPABLE OF PASSING SOLIDS.
A STRAINER SHOULD BE USED ON THE PUMP INTAKE TO
ENSURE THAT THE PUMP'S RATED SOLIDS CAPACITY IS
NOT EXCEEDED.
CAUTION: DO NOT EXCEED 8.6 BAR (125 PSIG) AIR
SUPPLY PRESSURE.

WIL-11110 - E- 04 9 WILDEN PUMP & ENGINEERING, LLC
SUGGESTED INSTALLATION
NOTE: In the event of a power failure, the shut off valve
should be closed, if the restarting of the pump is not
desirable once power is regained.
AIR OPERATED PUMPS: To stop the pump from
operating in an emergency situation, simply close the
shut off valve (user supplied) installed in the air supply
line. A properly functioning valve will stop the air supply
to the pump, therefore stopping output. This shut off
valve should be located far enough away from the
pumping equipment such that it can be reached safely
in an emergency situation.
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This illustration is a generic
representation of an air-operated
double-diaphragm pump.

WILDEN PUMP & ENGINEERING, LLC 10 WIL-11110 - E- 04
SUGGESTED OPERATION & MAINTENANCE
OPERATION: The H400S is pre-lubricated, and does not
require in-line lubrication. Additional lubrication will
not damage the pump, however if the pump is heavily
lubricated by an external source, the pump’s internal
lubrication may be washed away. If the pump is then
moved to a non-lubricated location, it may need to be
disassembled and re-lubricated as described in the
ASSEMBLY/DISASSEMBLY INSTRUCTIONS.
Pump discharge rate can be controlled by limiting the
volume and/or pressure of the air supply to the pump.
An air regulator is used to regulate air pressure. A needle
valve is used to regulate volume. Pump discharge rate
can al s o b e c ontro lled b y thro t tling the p ump di s c har g e
by partially closing a valve in the discharge line of the
pump. This action increases friction loss which reduces
flow rate. (See Section 5.) This is useful when the need
exists to control the pump from a remote location.
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. The pump has reached a “deadhead”
situation and can be restarted by reducing the fluid
discharge pressure or increasing the air inlet pressure.
The Wilden H400S pump runs solely on compressed
air and does not generate heat, therefore your process
fluid temperature will not be affected.
MAINTENANCE AND INSPECTIONS: Since each
application is unique, maintenance schedules may
be different for every pump. Frequency of use, line
pressure, viscosity and abrasiveness of process fluid
all affect the parts life of a Wilden pump. Periodic
inspections have been found to offer the best
means for preventing unscheduled pump downtime.
Personnel familiar with the pump’s construction and
service should be informed of any abnormalities that
are detected during operation.
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.
TROUBLESHOOTING
Pump will not run or runs slowly.
1. Ensure that the air inlet pressure is at least 0.4 bar
(5 psig) above startup pressure and that the differential
pressure (the difference between air inlet and liquid
discharge pressures) is not less than 0.7 bar (10 psig).
2. Check air inlet filter for debris (see recommended
installation).
3. Check for extreme air leakage (blow by) which
would indicate worn seals/bores in the air valve,
pilot spool, main shaft.
4. Disassemble pump and check for obstructions
in the air passageways or objects which would
obstruct the movement of internal parts.
5. Check for sticking ball check valves. If material being
pumped is not compatible with pump elastomers,
swelling may occur. Replace ball check valves and
seals with proper elastomers. Also, as the check
valve balls wear out, they become smaller and can
become stuck in the seats. In this case, replace balls
and seats.
6. Check for broken inner piston which will cause the
air valve spool to be unable to shift.
7. Remove plug from pilot spool exhaust.
Pump runs but little or no product flows.
1. Check for pump cavitation; slow pump speed
down to allow thick material to flow into liquid
chambers.
2. Verify that vacuum required to lift liquid is not
greater than the vapor pressure of the material
being pumped (cavitation).
3. Check for sticking ball check valves. If material being
pumped is not compatible with pump elastomers,
swelling may occur. Replace ball check valves and
seats with proper elastomers. Also, as the check
valve balls wear out, they become smaller and can
become stuck in the seats. In this case, replace balls
and seats.
Pump air valve freezes.
1. Check for excessive moisture in compressed
air. Either install a dryer or hot air generator for
compressed air. Alternatively, a coalescing filter
may be used to remove the water from the
compressed air in some applications.
Air bubbles in pump discharge.
1. Check for ruptured diaphragm.
2. Check tightness of outer pistons (refer to Section 7).
3. Check tightness of fasteners and integrity of
o-rings and seals, especially at intake manifold.
4. Ensure pipe connections are airtight.
Product comes out air exhaust.
1. Check for diaphragm rupture.
2. Check tightness of outer pistons to shaft.

WIL-11110 - E- 04 11 WILDEN PUMP & ENGINEERING, LLC
Section 7
PUMP DISASSEMBLY
Tools Required:
• 9/16" Wrench
• 3/4" Wrench
• Adjustable Wrench
• Vise equipped w/
soft jaws (such as
plywood, plastic
or other suitable
material)
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 the
pump. Disconnect all intake, discharge, and air lines. Drain the pump by turning it
upside down and allowing any fluid to flow into a suitable container. Be aware of
any hazardous effects of contact with your process fluid.
Step 1
Please note alignment marks on
liquid chambers. Use to properly
align center section with liquid
chambers.
Step 2
Using a 3/4" wrench, loosen the
discharge manifold from the
liquid chambers.
Step 3
Remove the discharge manifold to
expose the top left valve ball. Note:
the H400S pump does not use valve
balls in the amplification chamber.

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Step 4
Remove the discharge valve ball,
valve seat and valve seat o-ring from
the left liquid chamber and inspect
for nicks, gouges, chemical attack or
abrasive wear. Replace worn parts
with genuine Wilden parts.
Step 5
To ensure no excessive wear
or damage has occurred to the
amplification chamber plug o-rings,
remove plugs located between top
and bottom tee sections and elbows,
right side of pump only. Inspect and
replace seat plug o-rings if necessary.
Install buna o-ring on air side of plug
and the encapsulated Viton®o-ring
on liquid side of plug.
Step 6
Using a 3/4" wrench, loosen the inlet
manifold from the liquid chambers.
Step 7
Lift liquid chambers and center
section from inlet manifold to
expose left inlet valve ball, valve
seat and valve seat o-ring. Inspect
for nicks, gouges, chemical attack or
abrasive wear.
Step 8
Using a 9/16" wrench, remove the
liquid chamber from the center
section.
Step 9
The liquid chamber should be
removed to expose the diaphragm
and outer piston.
PUMP DISASSEMBLY

WIL-11110 - E- 04 13 WILDEN PUMP & ENGINEERING, LLC
Step 10
Using an adjustable wrench,
remove the diaphragm assembly
from diaphragm shaft by turning
counterclockwise.
Step 11
After loosening and removing
the diaphragm assembly, remove
opposite liquid chamber.
PUMP DISASSEMBLY
Step 13
To remove diaphragm assembly from
shaft, secure shaft with soft jaws (a vise
fitted with plywood, plastic or other
suitable material) to ensure shaft is not
nicked, scratched or gouged. Using an
adjustable wrench, remove diaphragm
assembly from shaft.
Step 12
After removing the opposite liquid
chamber, the remaining diaphragm
assembly and diaphragm shaft can
be easily removed.

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The outer piston on the side of
the amplification chamber has
an air passageway at the center
of the outer piston lug. This air
passageway allows air to flow
from the opposite air chamber to
the amplification chamber. This
principle is how the H400S high
pressure pump achieves a 2:1 ratio
of inlet air pressure to discharge
pressure. When reassembling the
H400S pump, the outer piston
with the air passageway has to be
positioned on the same side as the
amplification chamber. If it is not
reassembled correctly, the pump
will not operate and process fluid
will enter the air distribution system
through the air passageway located
at the shaft lug.
This same air passageway continues through the diaphragm shaft, exits
out of the diaphragm shaft via a 90º turn and into the air chamber located
on the wetted side of the pump. The air passageway has to be positioned in
the air chamber on the wetted side of the pump, opposite the amplification
chamber.
AIR PASSAGEWAY AIR PASSAGEWAYAIR PASSAGEWAY
H400S PISTON & SHAFT ORIENTATION

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AIR VALVE / CENTER SECTION DISASSEMBLY
Tools Required:
• 3/16" Hex Head
Wrench
• 1/4" Hex Head Wrench
• Snap Ring Pliers
• O-Ring Pick
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 the
pump. Disconnect all intake, discharge, and air lines. Drain the pump by turning it
upside down and allowing any fluid to flow into a suitable container. Be aware of
hazardous effects of contact with your process fluid.
Step 1
Using a 3/16” hex head wrench,
loosen air valve bolts.
Step 2
Remove muffler plate and air valve
bolts from air valve assembly.
Lift away air valve assembly and
remove air valve gasket and muffler
plate gasket for inspection. Replace
if necessary.
Step 3
Remove air valve end cap to expose
air valve spool by simply lifting
up on end cap once air valve bolts
are removed. Note: Pro-Flo V™ air
valve incorporates an end cap at
both ends of the air valve.
AIR VALVE
GASKET
MUFFLER
GASKET

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Step 4
Remove the air valve spool from the air
valve body by threading one air valve
bolt into the end of the air valve spool
and gently sliding the spool out of the
air valve body. Inspect seals for signs
of wear and replace entire assembly if
necessary. Use caution when handling
air valve spool to prevent damaging
seals. Note: Seals should not be
removed from assembly. Seals are not
sold separately.
Step 5
Remove pilot sleeve retaining snap
ring on both sides of center section
with snap ring pliers.
Step 6
Remove pilot spool sleeve from
center section.
AIR VALVE / CENTER SECTION DISASSEMBLY
Step 7
Using an o-ring pick, gently remove the o-ring from the opposite side of the
“notched end” on one side of the pilot spool. Gently remove the pilot spool from
pilot spool sleeve and inspect for nicks, gouges and wear. Replace pilot sleeve or
outer sleeve o-rings if necessary. During re-assembly, never insert the pilot spool
into the sleeve with the “notched end” first, this end incorporates the urethane
o-ring and will be damaged as it slides over the ports cut in the sleeve. Note:
seals should not be removed from pilot spool. Seals are not sold separately.
NOTCHED
END
Step 8
Check center section Glyd™ rings
for signs of wear. If necessary,
remove Glyd™ rings with o-ring
pick and replace.

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REASSEMBLY HINTS & TIPS
ASSEMBLY:
Upon performing applicable maintenance to the air
distributionsystem,the pump can nowbe reassembled.
Please refer to the disassembly instructions for photos
and parts placement. To reassemble the pump, follow
the disassembly instructions in reverse order. The air
distribution system needs to be assembled first, then
the diaphragms and finally the wetted path. Please find
the applicable torque specifications on this page. The
following tips will assist in the assembly process.
• Lubricate air valve bore, center section shaft and
pilot spool bore with NLGI grade 2 white EP bearing
grease or equivalent.
• Clean the inside of the center section shaft bore to
ensure no damage is done to new seals.
• A small amount NLGI grade 2 white EP bearing
grease can be applied to the muffler and air valve
gaskets to locate gaskets during assembly.
• Make sure that the exhaust port on the muffler plate
is centered between the two exhaust ports on the
center section.
• Stainless bolts should be lubed to reduce the
possibility of seizing during tightening.
PRO-FLO V™ MAXIMUMTORQUE SPECIFICATIONS
Description of Part Torque
Air Valve 13.6 N•m (120 in-lbs)
Air Chamber/Center Block 27.1 N•m (20 ft-lbs)
Outer Pistons, Rubber & PTFE 105.8 N•m (78 ft-lbs)
SHAFT SEAL INSTALLATION:
PRE-INSTALLATION
• Once all of the old seals have been removed, the
inside of the bushing should be cleaned to ensure
no debris is left that may cause premature damage
to the new seals.
INSTALLATION
The following tools can be used to aid in the installation
of the new seals:
Needle Nose Pliers
Phillips Screwdriver
Electrical Tape
• Wrap electrical tape around each leg of the needle nose
pliers (heat shrink tubing may also be used). This is done
to prevent damaging the inside surface of the new seal.
• With a new seal in hand, place the two legs of the needle
nose pliers inside the seal ring. (See Figure A.)
• Open the pliers as wide as the seal diameter will allow,
then with two fingers pull down on the top portion of
the seal to form kidney bean shape. (See Figure B.)
• Lightly clamp the pliers together to hold the seal into
the kidney shape. Be sure to pull the seal into as tight
of a kidney shape as possible, this will allow the seal to
travel down the bushing bore easier.
• With the seal clamped in the pliers, insert the seal into
the bushing bore and position the bottom of the seal
into the correct groove. Once the bottom of the seal is
seated in the groove, release the clamp pressure on the
pliers. This will allow the seal to partially snap back to its
original shape.
• After the pliers are removed, you will notice a slight
bump in the seal shape. Before the seal can be properly
resized, the bump in the seal should be removed as
much as possible. This can be done with either the
Phillips screwdriver or your finger. With either the side
of the screwdriver or your finger, apply light pressure
to the peak of the bump. This pressure will cause the
bump to be almost completely eliminated.
• Lubricate the edge of the shaft with NLGI grade 2
white EP bearing grease.
• Slowly insert the center shaft with a rotating motion.
This will complete the resizing of the seal.
• Perform these steps for the remaining seal.
Figure A
SHAFT SEAL
TAPE
Figure B
SHAFT SEAL
TAPE
NEEDLE NOSE
PLIERS

Section 8
EXPLODED VIEW & PARTS LISTING
H400S ALUMINUM TPE-Fitted EXPLODED VIEW
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— 2
— 3
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\4
\7
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/37
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— 22
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— 23
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15
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— 28
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— 34
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29
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