Wanner Engineering Hydra-Cell H-25-SD Manual

W0193A
WANNER ENGINEERING, INC.
1204 Chestnut Avenue, Minneapolis, MN 55403
TEL: [phone] FA X: [phone]
TOLL-FREE FAX [US only]: [phone]
www.hydra-cell.com
email: [e-mail]
H-25-SD, G-25-SD
SLURRY DUTY PUMPS
INSTALLATION & SERVICE
H25-991-2406A

2H25-991-2406A
H/G-25-SD Contents
Page
Specifications..........................................................................2
Dimensions .............................................................................3
Installation...............................................................................4
Maintenance............................................................................8
Service (Fluid End) .................................................................9
Service (Hydraulic End)........................................................15
Troubleshooting.....................................................................18
Maximum Capacity
rpm gpm I/min
H/G-25-X-SD 1050 20.0 76
H/G-25-E-SD 1150 20.2 77
Delivery @ Max Pressure
revs/gal revs/liter
H/G-25-X-SD 52 14
H/G-25-E-SD 57 15
Max Inlet Pressure 50 psi (3.5 bar)
Discharge Pressure
Maximum: 300 psi (21 bar)
Max Temperature
Pump Head: 140°F (60°C)
Hydraulic End: 180°F (82°C)
Inlet Port
H-25-SD: 1-1/2 inch NPT
G-25-SD: 1-1/2 inch BSPT
Discharge Port
H-25-SD: 1 inch NPT
G-25-SD: 1 inch BSPT
Shaft Diameter 1-1/8 inch (28.58 mm)
Shaft Rotation Bi-directional
Bearings Tapered roller
Oil Capacity 2-1/2 US quarts (2.4 liters)
Weight 90 lbs (40.9 kg)
+
50 x rpm
63,000
gpm x psi
1,460
= electric motor HP*
H/G-25-SD Specifications
+
50 x rpm
84,428
lpm x bar
511
= electric motor kW*
Calculating Required
Horsepower (kW)*
* rpm equals pump shaft rpm. HP/kW is required application
power. Use caution when sizing motors with variable speed
drives.

3H25-991-2406A
H/G-25-SD Specifications
RPM
0
NPSHr (feet of water)
NPSHr (meters of water)
2
1
4
6
8
10
12
14
16
18
20
24
26
22
0
2
3
4
5
6
7
1050 1160
100 200 300 400 500 600 700 800 900 1000 1100 1200
H/G-25-X-SD
H/G-25-E-SD
W0210
RPM
0 12001000800600400200
1050
1150
H/G-25-E-SD
H/G-25-X-SD
Gallons Per Minute
Liters Per Minute
16.0
20.0
24.0
32.0
36.0
40.0
28.0
44.0
48.0
52.0
56.0
60.0
64.0
68.0
72.0
76.0
80.0
84.0
88.0
4.0
8.0
12.0
0
24.0
0
22.0
20.0
18.0
16.0
14.0
12.0
10.0
8.0
6.0
4.0
2.0
300 PSI (21 bar)
W0211
Performance Net Positive Suction Head –
NPSHr
H/G-25-SD Dimensions
3.2
(81.3)
18.0
(457)
14.8
(376)
0.50
(12.7)
0.50
(12.7)
3.1
(78.7)
11.0
(279)
0.8
(20.3)
1.5
(38.1)
7.5
(190.5)
10.0
(254)
0.25
(6.4)
Slot Width
0.42
(10.7) Slot Width
4.5
(114)
2.25
(57.2)
3.4
(86.4)
10.0
(254)
5.63
(143)
Ø1.125
(28.58)
1.4
(35.6)
Oil
Drain
3/8" - 18 NPT
(Drain Port)
Oil Fill Cap
0.25
(6.4)
Keyway
Outlet
H-25-SD: 1" NPT
G-25-SD: 1" BSPT
Inlet
H-25-SD: 1 1/2" NPT
G-25-SD: 1 1/2" BSPT
W0209A

4H25-991-2406A
H/G-25-SD Installation
Important Precautions
Adequate Fluid Supply. To avoid cavitation and
premature pump failure, be sure that the pump will have
an adequate fluid supply and that the inlet line will not be
obstructed. See “Inlet Piping”.
Positive Displacement. This is a positive-displacement
pump. To avoid severe system damage if the discharge line
ever becomes blocked, install a relief valve downstream
from the pump. See “Discharge Piping”.
Safety Guards. Install adequate safety guards over
all pulleys, belts, and couplings. Follow all codes and
regulations regarding installation and operation of the
pumping system.
Shut-Off Valves. Never install shut-off valves between
the pump and discharge pressure regulator, or in the
regulator bypass line.
Freezing Conditions. Protect the pump from freezing.
See also the Maintenance Section.
Consult the Factory for the following situations:
• Extreme temperature applications – above 120° F (49°
C) or below 40° F (5° C)
• Pressure feeding of pumps
• Viscous or abrasive fluid applications
• Chemical compatibility problems
• Hot ambient temperatures – above 110° F (43° C)
• Conditions where pump oil may exceed 180° F (82° C)
because of a combination of hot ambient temperatures,
hot fluid temperature, and full horsepower load — an
oil cooler may be required.
Location
Locate the pump as close to the supply source as possible.
Install it in a lighted clean space where it will be easy to inspect
and maintain. Allow room for checking the oil level, changing
the oil, and removing the manifold support (43), manifold (7),
and valve plate (18).
Mounting
The pump shaft can be rotated in either direction.
To prevent vibration, securely attach the pump and motor to a
level, rigid base.
On a belt-drive system, align the sheaves accurately: poor
alignment wastes horsepower and shortens the belt and bearing
life. Make sure the belts are properly tightened, as specified by
the belt manufacturer.
On a direct-drive system, align the shafts accurately. Unless
otherwise specified by the coupling manufacturer, maximum
parallel misalignment should not exceed 0.015 in. (0.4 mm)
and angular misalignment should be held to 1° maximum.
Careful alignment extends life of the coupling, pump, shafts,
and support bearings. Consult coupling manufacturer for exact
alignment tolerances.
W0198

5H25-991-2406A
H/G-25-SD Installation
Inlet Piping (Suction Feed)
Caution: Do not pump at fluid temperatures above 140° F
(60° C). Consult the Pump Specifications Manual for current
ratings, based on the pump head material.
Install draincocks at any low points of the suction line, to permit
draining in freezing conditions.
Provide for permanent or temporary installation of a vacuum
gauge to monitor the inlet suction. Vacuum at the pump inlet
should not exceed 7 in. Hg at 70°F (180 mm Hg at 71°C).
Do not supply more than one pump from the same inlet line.
Supply Tank
See the illustration on page 2.
Use a supply tank that is large enough to provide time for any
trapped air in the fluid to escape. The tank size should be at
least twice the maximum pump flow rate.
Isolate the pump and motor stand from the supply tank, and
support them separately.
Install a separate inlet line from the supply tank to each
pump.
Install the inlet and bypass lines so they empty into the supply
tank below the lowest water level, on the opposite side of the
baffle from the pump suction line.
If a line strainer is used in the system, install it in the inlet line
to the supply tank.
To reduce aeration and turbulence, install a completely-
submerged baffle plate to separate the incoming and outgoing
liquids.
Install a vortex breaker in the supply tank, over the outlet port
to the pump.
Place a cover over the supply tank, to prevent foreign objects
from falling into it.
Loctite is a registered trademark of Loctite Corporation.
ScotchBrite is a trademark of 3M Company.
Hose Size and Routing
Size the suction line at least one size larger than the pump
inlet, and so that the velocity will not exceed 1 to 3 ft/sec (0.3
to 0.9 m/sec):
Velocity (ft/sec) = 0.408 x GPM
Pipe I.D.2*
*where pipe I.D. is in inches
Keep the suction line as short and direct as possible.
The smallest permissible inlet hose size is:
1 to 10 gpm............................................................ 1-1/2 in. I.D.
11 to 20 gpm................................................................ 2 in. I.D.
1 to 38 liters/min......................................................38 mm I.D.
39 to 76 liters/min....................................................50 mm I.D.
Use flexible hose and/or expansion joints to absorb vibration,
expansion, or contraction.
If possible, keep the suction line level. Do not have any high
points to collect vapor unless these high points are vented.
To reduce turbulence and resistance, do not use 90° elbows.
If turns are necessary in the suction line, use 45° elbows or
arrange sweeping curves in the flexible inlet hose.
If a block valve is used, be sure it is fully opened so that the flow
to the pump is not restricted. The opening should be at least
the same diameter as the inlet plumbing I.D.
Do not use a line strainer or filter in the suction line unless
regular maintenance is assured. If used, it should have a free-
flow area of at least three times the free-flow area of the inlet.
Install piping supports where necessary to relieve strain
on the inlet line and to minimize vibration. These supports
are essential because the manifold is plastic and more
susceptible to damage.
Always tighten all piping connections, gauges, and regulators
before installing the piping cluster into the pump manifold.
Inlet Piping (Pressure Feed)
Provide for permanent or temporary installation of a vacuum/
pressure gauge to monitor the inlet vacuum or pressure.
Pressure at the pump inlet should not exceed 50 psi (3.5 bar);
if it could get higher, install an inlet pressure regulator.
Do not supply more than one pump from the same inlet line.
Always tighten all piping connections, gauges, and regulators
before installing the piping cluster into the pump manifold.

6H25-991-2406A
Minimizing Acceleration Head and Frictional Losses
To minimize the acceleration head and frictional losses:
• Keep inlet lines less than 3 ft (1 m) long
• Use at least 1-1/2 in. (38 mm) I.D. inlet hose
• Use soft hose (low-pressure hose, noncollapsing) for the
inlet lines
• Minimize fittings (elbows, valves, tees, etc.)
•Use a suction stabilizer on the inlet.
Net Positive Suction Head
NPSHa must be equal to or greater than NPSHr. If not, the
pressure in the pump inlet will be lower than the vapor pressure
of the fluid— and cavitation will occur.
Calculating the NPSHa
Use the following formula to calculate the NPSHa:
NPSHa = Pt + Hz - Hf - Ha - Pvp
where:
Pt = Atmospheric pressure
Hz = Vertical distance from surface liquid to pump centerline (if
liquid is below pump centerline, the Hz is negative)
Hf = Friction losses in suction piping
Ha = Acceleration head at pump suction
Pvp = Absolute vapor pressure of liquid at pumping
temperature
NOTES:
• In good practice, NPSHa should be 2 ft greater than
NPSHr
• All values must be expressed in feet of liquid
Atmospheric Pressure at Various Altitudes
Altitude Pressure Altitude Pressure
(ft) (ft of H2O) (ft) (ft of H2O)
0 33.9 1500 32.1
500 33.3 2000 31.5
1000 32.8 5000 28.2
Discharge Piping
NOTE: Consult the Factory before manifolding two or more
pumps together.
Hose and Routing
Size the discharge line one or two sizes larger than the pump
discharge opening. Use the shortest, most direct route.
Size the discharge line so that the velocity will not exceed 7
- 10 ft/sec (2 to 3 m/sec):
Velocity (ft/sec) = 0.408 x GPM
Pipe I.D.2*
*where pipe I.D. is in inches
Inlet Calculations
Acceleration Head
Calculating the Acceleration Head
Use the following formula to calculate acceleration head losses.
Subtract this figure from the NPSHa, and compare the result to
the NPSHr of the Hydra-Cell pump.
Ha = (L x V x N x C) ÷ (K x G)
where:
Ha = Acceleration head (ft of liquid)
L= Actual length of suction line (ft) — not equivalent length
V= Velocity of liquid in suction line (ft/sec) [V = GPM x (0.408
÷ pipe ID2)]
N= RPM of crank shaft
C= Constant determined by type of pump — use 0.066 for the
H-25-SD and G-25-SD Hydra-Cell pumps
K= Constant to compensate for compressibility of the fluid
— use: 1.4 for de-aerated or hot water; 1.5 for most liquids;
2.5 for hydrocarbons with high compressibility
G= Gravitational constant (32.2 ft/sec2)
Friction Losses
Calculating Friction Losses in Suction Piping
When following the above recommendations (under “Inlet
Piping”) for minimum hose/pipe I.D. and maximum length,
frictional losses in the suction piping are negligible (i.e., Hf =
0) if you are pumping a water-like fluid.
When pumping more viscous fluids such as lubricating oils,
sealants, adhesives, syrups, varnishes, etc., frictional losses
in the suction piping may become significant. As Hf increases,
the available NPSH (NPSHa) will decrease, and cavitation will
occur.
In general, frictional losses increase with increasing viscosity,
increasing suction-line length, increasing pump flowrate, and
decreasing suction-line diameter. Changes in suction-line
diameter have the greatest impact on frictional losses; a 25%
increase in suction-line diameter cuts losses by more than
two times, and a 50% increase cuts losses by a factor of five
times.
Use one of the following formulas to calculate friction losses in
your system. Subtract the resulting figure from the NPSHa, and
compare the result to the NPSHr of the Hydra-Cell pump.
For flowrates of 1 to 10 gpm, use:
Hf = 0.38 ft x CPS x GPM x L x 1.5
4
100 10 3 ID
For flowrates of 11 to 20 gpm, use:
Hf = 0.25 ft x CPS x GPM x L x 2 4
100 20 3 ID
where:
CPS = Viscosity of pumped material (in centipoise)
L = Length of suction line (in feet), and
ID = Pipe I.D. (in inches)
H/G-25-SD Installation
( )
( )

7H25-991-2406A
Before Initial Start-Up
Before you start the pump, be sure that:
• All shut-off valves are open, and the pump has an adequate
supply of fluid.
• All connections are tight.
• The oil level is approximately 1 in. (2.5 cm) from the top of
the fill port — so that the floor of the upper reservoir within
the pump housing is flooded and the chamber itself is about
1/4 full, allowing for oil expansion as the pump runs and heats
up.
• The relief valve on the outlet of the pump is adjusted so the
pump starts under minimum pressure.
• All pulleys and belts are properly aligned, and belts are
tensioned according to specification.
• ll pulleys and belts have adequate safety guards.
Initial Start-Up Procedure
1. Turn on power to the pump motor.
2. Check the inlet pressure or vacuum. Inlet vacuum must not
exceed 7 in. Hg at 70° F (180 mm Hg at 21° C). Inlet pressure
must not exceed 50 psi (3.5 bar).
3. If you hear any erratic noise or if the flow is unsteady, refer
to the Troubleshooting Section.
4. If the system has an air lock and the pump fails to prime:
a. Turn off the power.
b. Remove the drain plug (4) on the bottom center of the
manifold.
Note: Fluid may come out of this port when the plug
is removed. Provide an adequate catch basin for fluid
spillage, if required. Fluid will come out of this port
when the pump is started, so we recommend that you
attach adequate plumbing from this port so fluid will
not be sprayed or lost. Use high-pressure-rated hose
and fittings from this port. Take all safety precautions
to assure safe handling of the fluid being pumped.
c. Jog the system on and off until the fluid coming from this
port is air-free.
d. Turn off the power.
e. Remove the plumbing that was temporarily installed, and
reinstall the drain plug (4).
5. Adjust the discharge pressure regulator to the desired
operating and bypass pressures.
6. After the pressure regulator is adjusted, set the “pop-off”
safety relief valve at 100 psi (6.9 bar) higher than the
desired operating pressure. To verify this setting, adjust the
discharge pressure regulator upward until the relief valve
opens. Follow the recommendations in the above Note
(Step 4b) for handling the fluid that will come from the relief
valve.
7. Reset the discharge pressure regulator to the desired system
pressure.
8. Provide a return line from the relief valve to the supply tank,
similar to the bypass line from the pressure regulator.
H/G-25-SD Installation
The smallest permissible discharge hose size is:
1 to 10 gpm............................................... 11/16 (0.687) in. I.D.
11 to 20 gpm................................................................ 1 in. I.D.
1 to 38 liters/min...................................................... 17 mm I.D.
39 to 76 liters/min....................................................25 mm I.D.
Use flexible hose between the pump and hard piping, to absorb
vibration, expansion, or contraction.
Never install a shutoff valve in the discharge line between the
pump and the regulator, or in the bypass line.
Select pipe or hose with a working pressure rating of at least
1.5 times the maximum system pressure. Example: Select a
300-psi W.P.-rated hose for systems to be operated at 200-
psi-gauge pressure.
Support the pump and piping independently. These supports
are essential, because the manifold and inlet/outlet
adapters are plastic and more susceptible to damage.
Pressure Regulation
IInstall a pressure regulator or unloader in the discharge
line. Bypass pressure must not exceed the pressure limit of
the pump.
Size the regulator so that, when fully open, it will be large enough
to relieve the full capacity of the pump without overpressurizing
the system.
Locate the valve as close to the pump as possible and ahead
of any other valves.
Adjust the pressure regulating valve to no more than 10% over
the maximum working pressure of the system. Do not exceed
the manufacturer’s pressure rating for the pump or regulator.
Route the bypass line to the supply tank, or to the suction line
as far as possible from the pump (to reduce the chance of
turbulence).
If the pump will be operating for a long time with the discharge
closed and fluid bypassing, install a thermal protector set to
trip at 120° F (49° C) in the bypass line — to prevent severe
temperature buildup in the bypassed fluid.
Caution: Never install shutoff valves in the bypass line or
between the pump and pressure regulator or relief valve.
Provide for permanent or temporary installation of a pressure
gauge to monitor the discharge pressure at the pump.
For additional system protection, install a “pop-off” safety relief
valve in the discharge line, downstream from the pressure
regulator.
Always tighten all piping connections, gauges, and regulators
before installing the piping cluster into the pump manifold.

8H25-991-2406A
H/G-25-SD Maintenance
NOTE: The numbers in parentheses are the Ref. Nos. on
the illustrations in the Parts Manual.
Daily
Check the oil level and the condition of the oil. The oil level
should be 1 in. (2.5 cm) from the top of the fill port — so that the
floor of the upper reservoir within the pump housing is flooded
and the chamber itself is about 1/4 full, allowing for oil expansion
as the pump runs and heats up.
Use the appropriate Wanner Hydra-Oil brand motor oil for the
application — contact Wanner Engineering if in doubt.
Caution: If you are losing oil but don’t see any external
leakage, or if the oil becomes discolored and contaminated,
one of the diaphragms (21) may be damaged. Refer to the
Service Section. Do not operate the pump with a damaged
diaphragm.
Caution: Do not leave contaminated oil in the pump housing
or leave the housing empty. Remove contaminated oil as
soon as discovered, and replace it with clean oil.
Periodically
Change the oil after the first 100 hours of operation, and then
according to the guidelines below.
Hours Between Oil Changes @ Various
Process Fluid Temperatures
<90°F <140°F <180°F
Pressure RPM (32°C) (60°C) (82°C)
Slurry Duty Pump Head
<300 psi (21 bar) <1200 2,000 1,500 –
<800 4,000 3,000 –
NOTE: Minimum oil viscosity for proper hydraulic end
lubrication is 16-20 cST (80-100 SSU).
NOTE: Use of an oil cooler is recommended when hydraulic
end oil exceeds 180°F (82°C).
When changing, remove the drain plug (36) at the bottom of the
pump so all oil and accumulated sediment will drain out.
Caution: Do not turn the drive shaft while the oil reservoir
is empty.
Check the inlet pressure or vacuum periodically with a gauge.
If vacuum at the pump inlet exceeds 7 in. Hg (180 mm Hg),
check the inlet piping system for blockages. If the pump inlet
is located above the supply tank, check the fluid supply level
and replenish if too low.
Caution: Protect the pump from freezing. Refer also to the
“Shutdown Procedure”.
Shutdown Procedure During
Freezing Temperatures
Take all safety precautions to assure safe handling of the
fluid being pumped. Provide adequate catch basins for
fluid drainage and use appropriate plumbing from drain
ports, etc. when flushing the pump and system with a
compatible antifreeze.
1. Adjust the discharge pressure regulating valve so the pump
runs under minimum pressure. Stop the pump.
2. Drain supply tank; open any draincocks in system piping and
collect drainage; remove plug (4) from manifold and collect
drainage.
3. Close draincocks in system piping and replace manifold
plug.
4. Fill supply tank with enough antifreeze to fill system piping
and pump.
NOTE: Disconnect the system return line from the supply
tank and connect it to a separate reservoir.
5. Start the pump and allow it to run until the system is filled
with antifreeze. NOTE: If the system has an airlock and
the pump fails to prime, follow step 4 of the Initial Start-
Up Procedure to clear the air.
6. When mostly antifreeze is flowing from the system return line
stop the pump. Connect the system return line back to the
supply tank and circulate the antifreeze for a short period.
7. It is also good practice to change the oil in the hydraulic
end before storage for an extended period. This will
remove any accumulated condensation and sediment from
the oil reservoir. Drain and refill the hydraulic end with the
appropriate Hydra-Oil and operate the pump for a short
period to assure smooth performance.

9H25-991-2406A
H/G-25-SD Service (Fluid End)
Tools and Supplies
The following tools and supplies are recommended for servicing
the fluid end of the pump:
• Wanner H/G-25 Tool Kit
• 1/2-in. drive socket wrench
• 8-mm and 10-mm hex-bit sockets
• 16-mm box-end wrench
• Straightedge (at least 10 in. long)
• Two 2-in. high blocks, approximately 2 to 3 in. wide and 6 to
8 in. long
• 5 mm hex Allen wrench
• Medium Phillips-head screwdriver
• Mallet
• Small torque wrench — rated to at least 27 in.-lbs (3 N-m)
• Torque wrench — rated to at least 50 ft-lbs (68 N-m)
• New oil
• Grease or petroleum jelly
• Water or compatible solvent for cleaning
The numbers in parentheses are the Reference
Numbers on the exploded view illustrations found
in this manual and also in the Parts Manual.
This section explains how to disassemble and inspect all
easily-serviceable parts of the pump. Repair procedures
for the hydraulic end (oil reservoir) of the pump are
included in a later section of the manual.
Caution: Do not disassemble the hydraulic end
unless you are a skilled mechanic. For assistance,
contact Wanner Engineering (Tel [phone] or
Fax [phone]) or the distributor in your area.
Caution: The four capscrews (26) that screw through
the back of the housing into the cylinder casting
hold the casting over the hydraulic end of the pump.
Do not remove them except when repairing the
hydraulic end.

10 H25-991-2406A
W0202
2. Remove and Inspect Valve
Assemblies (3, 11-17, 44-47)
Note: Wanner Repair Kits contain some or all of the required
components to replace items (3), (11-17), and (44-47), as well
as all O-rings for sealing the manifold to the valve plate.
Consult the appropriate Parts Manual for your pump to
determine which Repair Kit to order.
Remove the Valve Assemblies
The three inlet and three outlet valve assemblies in the pump
are identical (but face in opposite directions). One at a time,
remove each valve assembly , then inspect and reinstall the
valve assembly as outlined below. Be careful not to bend or
break any of the metal valve components, and not to gouge or
scrape the plastic valve plate.
Set the valve plate on 2-in. high blocks, with the valve assemblies
facing down. As you press out each valve assembly during the
following procedure, be sure there is enough open space below
so that the valve can come out of its bore unobstructed.
To remove each valve assembly:
H/G-25-SD Service (Fluid End)
Service Procedure
1. Remove Manifold Support
(43), Manifold (7), and Valve
Plate (18)
a. With an 8-mm (or 5/16-in.) hex Allen wrench, and a 16-mm
box-end wrench, remove all nuts (31) and capscrews (5)
around the manifold support plate. Do not remove the four
capscrews (26) that are installed through the back of the
pump housing.
b. With a 10-mm hex Allen wrench, remove the centerbolt
(1) and its washer (2) in the center of the manifold support
plate.
Caution: Do not turn the pump drive shaft while the
manifold and valve plate are off the pump, except
when removing diaphragms or repriming the hydraulic
cells.
c. Remove the manifold support (43) and manifold (7).
d. Inspect the manifold support and manifold for warpage or
wear around the inlet and outlet ports. Also inspect the
manifold for warpage or wear in the area of the flow channels,
especially where the valve assemblies contact the manifold.
If wear is excessive, replace the manifold with a new one.
To check the manifold support for warpage, lay it on a flat
surface and place a straightedge across it. Check both sides
of the plate for warpage.
To check the manifold for warpage, first be sure any plugs
or O-rings are removed, then lay it on a flat surface with the
flow channels facing you. Place a straightedge across the
raised surfaces of the manifold.
Note: A machined recess was cut around the perimeter
of the manifold at the factory. Do not mistake this feature
for warpage.
A warped manifold suppor t or manifold should be
replaced.
e. With a 5-mm hex Allen wrench, remove the three socket-
head capscrews (39) that hold the valve plate to the cylinder
casting.
Note: There is an O-ring (48) under the head of each
capscrew, which acts as a washer between it and the
plastic valve plate.

11 H25-991-2406A
H/G-25-SD Service (Fluid End)
a. Inlet (3 center valves). From the large hole at the bottom
of the diaphragm pocket in the valve plate, press down on
the spring retainer (16) until the valve seat, valve, and spring
fall out of the bore.
Press and tap down as required, working your way around
the edge of the spacer to force the shell subassembly, crush
seal, and spacer evenly out of the valve bore.
b. Outlet (3 outer valves). From the small hole at the bottom
of the diaphragm pocket in the valve plate, and through the
valve seat bore, press down evenly on the valve (13) until it
stops against the spring retainer.
Continue pressing or tapping, as required, until the spacer,
crush seal, shell subassembly, spring, and valve fall out of
the valve bore.
Press and tap down as required, working your way around
the edge of the seat holder to force the spacer and seat
subassembly evenly out of the valve bore.
c. Inspect both sides of the valve plate for wear, including
the diaphragm pockets, valve bores, and shoulders at the
bottom of each bore. Also inspect the face of the valve
plate (adjacent to the valve bores) for wear, especially in the
areas where the O-rings seal between it and the manifold.
Using a straightedge, inspect both sides of the valve plate
for warpage. If there is warpage or excessive wear, replace
the valve plate.
Inspect the Valve Components
Inspect the individual components of each valve as follows:
a. Check the spring retainer (16) that is housed inside the shell
(45). Be sure to locate the polyurethane washer (17) that sits
in the spring retainer recess and supports the spring (14). If
the spring retainer is worn in the area of the four tabs that
guide and act as a stop for the valve, replace it.
Also look for wear in the area of the recess that supports
the spring. The polyurethane washer should have minimized
or prevented wear in this area if it stayed in place during
operation.
Press out the old spring retainer and push in a new one if
required. It is always a good idea to use a new polyurethane
washer in the spring retainer recess. Be careful to put only
one washer into each retainer recess.
b. Check the valve spring (14) for wear or damage. Compare
its free length to that of a new spring. A worn or otherwise
damaged spring should be replaced with a new one. Never
attempt to stretch an old spring and reuse it.
c. Check the valve (13) for uneven or excessive wear. If it has
developed an uneven wear pattern or is worn excessively,
do not reuse it — replace it with a new one. A valve with an
uneven wear pattern will not seal effectively, even against
a new seat, resulting in rough operation and reduced
output.
Note: Your pump has a urethane washer (44) in the
recess on the back side of each valve. It is there to
reduce or eliminate wear on the valve caused by motion
between the spring and valve. It also helps minimize
wear on the end of the spring. It is always a good idea
to replace these washers with new ones. Be careful to
put only one washer into each valve recess.
d. Remove the valve seat (3) from its holder (12). Inspect both
parts for wear and replace either or both as necessary. It is
always a good idea to use a new valve seat and O-ring (11)
in the valve seat holder.
Note: Whenever you replace a worn valve, valve seat, or
valve spring in any valve assembly, we recommend that
you replace them in all valve assemblies at that time,
to ensure the most reliable operation when you restart
the pump. We also recommend that you always replace
the washers and seals in the valve assemblies at that
time, for the most reliable operation. All the necessary
parts are included in a replacement valve kit and in a
complete fluid-end kit.

12 H25-991-2406A
H/G-25-SD Service (Fluid End)
Reinstall the Valve Assemblies
a. Clean the valve ports and shoulders in the valve plate (18)
with water or a compatible solvent. A ScotchBrite™ pad or
brush may be used to abrade any old buildup or residue,
but be careful not to scratch the plastic or wear away any of
the plastic valve plate material. Rinse the valve plate after
cleaning and lubricate the valve ports with a compatible
grease, oil, or lubricating gel such as petroleum jelly.
Caution: If the elastomers are made of EPDM, do not
use a petroleum-based lubricant on them. Instead, use
an EPDM-compatible lubricant. If the product is food-
grade, use a compatible food-grade lubricant.
b. Install new O-rings (11) and seats (3) into each valve seat
holder (12). Lubricate the O-rings.
c. Install new polyurethane washers (17, 44) into each spring
retainer recess and each valve recess, respectively. Install
the spring retainers (16) into their shells (45) before installing
the polyurethane washers in the retainers.
A small amount of grease or petroleum jelly should be used
to help the washers stay in place during the rest of the
assembly procedure. It is very important that these washers
stay in their proper place until assembly is completed. If they
do not, they could end up holding a valve open or clogging a
valve or filter downstream of the pump. In addition, they will
not do their job of minimizing wear of the spring retainers,
springs, and valves if they are not properly in place.
d. Install a new crush seal (46) on three of the shell
subassemblies just completed above, for use in the outlet
valves. Press the spacers (15) onto the crush seals to create
a five-piece subassembly for each outlet valve. It is important
to use new crush seals during each rebuilding, because they
hold the spacers to the shells during subsequent assembly
procedures. Using new crush seals also ensures proper
compression on the valve assemblies when the manifold is
clamped to the valve plate.
Consult the illustration below for proper orientation of the
spring retainer tabs for both the inlet and outlet valves.
e. Inlet (3 center valves). Insert the three remaining spacers
(15) into the inner ring of valve bores in the valve plate. The
flat, flanged end must be facing down toward the shoulder
of the valve plate.
Note: You may have to press the spacers slightly, as
there is a line-to-line fit between the outer diameter of
the spacer and the valve bore.
WRONG: Retainer
leg pointing toward
center of pump.
RIGHT
Installing Valve Retainers
Into Valve Plate
W0212
Next, insert the remaining crush seals (46) onto the nose
of the inlet valve spacers. The seals must fit around the
nose of the spacers.
Insert the three-piece shell subassemblies (45, 16, 17) into
the inlet valve bores. They too may have to be pressed
slightly, as there is a line-to-line fit between the outer
diameter of the shell and the valve bore. Be sure the nose
of the shell (45) presses into the inner diameter of the crush
seal (46). The shaft rotator (from the Wanner Tool Kit) can
be used to press down evenly on the shell subassembly to
get the proper fit.
Before continuing, check that each polyurethane washer
is in its proper place, nested down into the recess of each
spring retainer.
Insert the spacers (47) into the valve bores so that they rest
on top of the shell subassemblies. Insert the springs (14)
and valves (13), ensuring that each valve has a polyurethane
washer (44) pressed into its recess — to minimize wear on
the valve and the end of the spring.
Finally, press the valve seat subassemblies (3, 12, 11) down
into the valve bores, compressing the valve spring slightly.
The valve seat O-ring should be lubricated with grease
or petroleum jelly to ease assembly. There is substantial
interference between the O-ring and valve bore, so be
careful not to shear the O-ring by driving it in too quickly.
Use the seal inserter (from the Wanner Tool Kit) to push
evenly on the seat, rocking very slightly, if required, to ease
the O-ring into the bore. Push down on the valve until it hits
the stops on the spring retainer, then let it pop back up to
the seat to ensure proper operation.
f. Outlet (3 outer valves). Press the three remaining valve
seat subassemblies (11, 3, 12) into the outer ring of valve
bores in the valve plate. The flat, metal end of the valve
seat holder (12) must be facing down toward the shoulder
of the valve plate. The valve bore and O-ring should be
lubricated with grease or petroleum jelly to ease assembly.
There is substantial interference between the O-ring and
valve bore, so be careful not to shear the O-ring by driving
it in too quickly.
Use the seal inserter to push the seat into the valve bore
until it is flush with the plate, then use the shaft rotator and
push down on the seats until they hit the shoulder at the
bottom of each bore.
Insert the spacers (47) into the valve bores so they rest on
top of the valve seats. Place the valves (13) and springs (14)
onto the seats, ensuring that each valve has a polyurethane
washer (44) pressed into its recess.
Finally, insert the five-piece shell subassemblies into the
bores, after checking that each polyurethane washer is in
its proper place, nested down in the recess of each spring
retainer. You may have to press slightly, as there is a line-
to-line fit between the outer diameter of the shell and the
valve bore.
From the other side of the valve plate (through the diaphragm
pocket), push on the valve until it hits the stops on the
spring retainer, then let it pop back to the seat to ensure
proper operation. You may have to lightly hold the shell
subassembly in place when doing this.

13 H25-991-2406A
H/G-25-SD Service (Fluid End)
3. Inspect and Replace
Diaphragms (22)
a. Lift one of the diaphragms by one edge, and turn the
pump shaft until the diaphragm pulls up. This will expose
machined cross-holes in the valve plunger shaft behind the
diaphragm.
b. Insert the plunger holder through the top hole to hold the
diaphragm up. The proper size tool is included in the Wanner
Tool Kit.
c. Remove the screw (19), O-ring (20), and follower (21) in the
center of the diaphragm.
d. Remove the diaphragm and inspect it carefully. A ruptured
diaphragm generally indicates a pumping system problem,
and replacing only the diaphragm will not solve the larger
problem. Inspect the diaphragm for the following:
• Half-moon marks. Usually caused by cavitation of the
pump (refer to “Troubleshooting”).
• Concentric circular marks. Usually caused by cavitation
of the pump (refer to “Troubleshooting”).
• Small puncture. Usually caused by a sharp foreign
object in the fluid, or by an ice particle.
• Diaphragm pulled away from the center screw or from
the cylinder sides. Usually caused by fluid being frozen
in the pump, or by overpressurization of the pump.
• Diaphragm becoming stiff and losing flexibility. Usually
caused by pumping a fluid that is incompatible with the
diaphragm material.
• Slice in ridge of diaphragm. Occurs when a diaphragm
is operated at temperatures below its rated capability.
• Diaphragm edge chewed away. Usually caused by
overpressurizing the system.
e. Inspect the plunger (23) for any rough surfaces or edges. Do
not remove the plunger from the valve plunger (54). Smooth
the surfaces and edges as necessary with emery cloth or a
fine file.
Caution: If a diaphragm has ruptured and foreign
material or water has entered the oil reservoir, do not
operate the pump. Check all diaphragms, then flush the
reservoir completely (as outlined below) and refill it with
fresh oil. Never let the pump stand with foreign material
or water in the reservoir, or with the reservoir empty.
f. Install a new diaphragm (or reinstall the old one, as
appropriate), ridge side out.
g. Clean and dry the screw (19), removing any oil from it. Apply
medium-strength threadlocker to the screw. Reinstall the
screw, the follower (21), and a new O-ring (20). Tighten to
18 in.-lbs (2.0 N-m).
h. Repeat the above inspection procedure (and replacement,
if necessary) with the other two diaphragms.
4. Flush Contaminant from
Hydraulic End (only if a
diaphragm has ruptured)
a. Remove the oil drain cap (34) and allow all oil and
contaminant to drain out.
b. Fill the reservoir with kerosene or solvent, manually turn the
pump shaft to circulate the kerosene, and drain.
Caution: If you have EPDM diaphragms, or if food grade
oil is in the reservoir, do not use kerosene or solvents.
Instead, flush with the same lubricant that is in the
reservoir. Pumps with EPDM diaphragms have an “E”
as the 7th digit of the Model No.
c. Repeat the flushing procedure (step b).
d. Fill the reservoir with fresh oil, manually turn the pump shaft
to circulate the oil, and drain once again.
e. Refill the reservoir. If the oil appears milky, there is still
contaminant in the reservoir. Repeat the flushing procedure
until the oil appears clean.
5A. Prime the Hydraulic Cells
a. With the pump horizontal and the fluid-end head removed,
fill the reservoir with the appropriate Hydra-Oil for the
application.
b. All air in the oil within the hydraulic cell (behind the
diaphragms) must be forced out by turning the shaft (and
thus pumping the piston). A shaft rotator is included in the
Wanner Tool Kit. Turn the shaft until a bubble-free flow of
oil comes from behind all the diaphragms. Watch the oil level
in the reservoir; if it gets too low during priming, air will be
drawn into the pistons (inside the hydraulic end) and will
cause the pump to run rough.
c. Wipe excess oil from the cylinder casting and diaphragms.
5B. Priming the Hydraulic Cells
for Kel-Cell Pumps
NOTE: Providing oil prime to Kel-Cell fitted pumps requires
pressure be applied to the diaphragms. This can be
done manually, with the system head pressure, or with
pressurized air if available. Review all methods below to
determine the procedure most suitable.

14 H25-991-2406A
Method #1 (system head pressure less than 2
psi)
a. Install the valve plate (16) but without the outlet valves
installed (or else remove the outlet valves; leave the seats
installed) onto the cylinder housing. Tighten the two socket-
head screws (41).
b. Fill the reservoir with appropriate Hydra-oil to the fill port.
c. With a blunt pointer (eraser end of pencil), reach in through
each outlet valve port and push the follower-diaphragm
backwards. Note the air bubbles coming out at the oil fill
port. Now turn the shaft about 1/2 turn.
d. Repeat depressing diaphragms and rotating shaft (approx.
4-6 times) until no more air bubbles escape and the oil has
dropped about 1 inch (25 mm) from the top of the fill port. The
hydraulic cells are now primed. Replace the oil fill cap.
e. Install outlet valve assemblies in each outlet valve port. See
Parts Manual for correct assembly order. You may have to
tip pump (head upward) in order to keep the valve centered
on the seat and allow the retainer to fit all the way into port
flush.
f. Install manifold (6) and complete installation.
Alternative Method #1:
With the pump horizontal, and the fluid-end head removed, fill
the reservoir with the appropriate Hydra-oil for the application.
Have a catch basin for oil that leaks from behind the diaphragms
when priming. Catch the oil and dispose of it properly; do not
reuse it.
a. All air in the oil within the hydraulic piston behind the
diaphragms must be forced out by turning the shaft (and thus
pumping the piston). A shaft rotator is included in the Hydra-
Cell Tool Kit. Keep pressure on the diaphragms while turning
the shaft until a bubble-free flow of oil comes from behind
all the diaphragms. Maintain the oil level in the reservoir. Do
not allow oil level to be lower than the reservoir.
b. Quickly attach the loaded valve plate (16) (before the oil runs
out past the diaphragms) with socket head screws (41), but
do not tighten completely. Leave a gap between the valve
plate and the cylinder housing. Turn the shaft 2-3 turns to
finish forcing out air behind the diaphragms. The hydraulic
cells are now primed. Now finish tightening the valve plate
with the two socket head screws and add pump manifold.
c. Wipe excess oil from around the pump head.
d. Check that the oil level is 1 inch (25 mm) from the top of the
fill port.
e. Replace the oil fill cap and complete installation.
Method #2 (head pressure greater than 2 psi)
This simple and clean method of priming the Hydra-cells
requires an inlet head pressure of at least 5 feet (1.5 m) or 2 psi
(.14 bar). The pressure source is required to hold the diaphragms
back while the piston moves so as to force out the air.
Completely assemble the pump and fill the reservoir with the
appropriate Hydra-oil to the fill port.
a. When tank head pressure is being used to prime, install
the pump back into the system and connect the tank supply
line to pump inlet. Pump discharge line may be connected
at this time, but end of line must be open to allow air to pass
out.
b. Slowly turn the pump shaft by hand and watch for bubbles
exiting the oil reservoir fill opening. This will take several
rotations; when no more bubbles come out and the reservoir
level has dropped about 1” (25 mm), the hydraulic cells are
primed.
c. Replace the oil fill cap and complete installation.
d. When compressed air is being used to prime, insert a
clean air hose to the pump inlet and restrict the pump outlet.
Turn the shaft a quarter turn and then apply air pressure into
the manifold to put pressure on the diaphragms. This will
force air out from inside the pistons and you will see bubbles
at the reservoir opening. Repeat for several rotations until
no more air bubbles come out and the reservoir level has
dropped about 1” (25 mm). The hydraulic cells are now
primed.
e. Replace the oil fill cap and complete installation.
6. Reinstall Valve Plate (18),
Manifold (7), and Manifold
Support (43)
a. Reinstall the valve plate (18), with the valve assemblies
installed as outlined above, onto the cylinder casting. Use
the three socket-head capscrews (39) with O-rings (48) to
fasten the valve plate to the cylinder casting. Verify that the
valve assemblies are still in place.
b. Reinstall the O-rings (8, 9, 10) between the valve plate and
manifold. Use petroleum jelly or lubricating gel to hold them
in place.
c. With the manifold support and manifold nested together,
and the centerbolt (1) and washer (2) in place through the
center hole, locate the drain plug (4) at the bottom and hold
the manifold and support against the valve plate. Tighten
the centerbolt by hand.
d. Insert all bolts (5), washers (6), and nuts (31) loosely. Align
the outer surfaces of the valve plate, manifold, and manifold
support, and torque the centerbolt to 45 ft-lbs (60 N-m).
e. Alternately tighten opposite bolts (5) until all are secured.
Torque to 45 ft-lbs (60 N-m).
H/G-25-SD Service (Fluid End)

15 H25-991-2406A
Tools and Supplies
The following supplies are recommended for servicing the
hydraulic end of the pump:
• 17 mm hex socket or box-end wrench
• 3/4 in. (19 mm) open-end or adjustable wrench
• 1 in (26 mm) open-end or adjustable wrench
• Emery cloth or ScotchBrite™ pad
• Grease
• Anaerobic seal sealant
The numbers in parentheses are the Reference Numbers
on the exploded view illustrations found in this manual and
also in the Parts Manual.
Caution: Do not disassemble the hydraulic end unless you
are a skilled mechanic. For assistance, contact Wanner
Engineering (Tel [phone] or Fax [phone]) or the
distributor in your area.
Caution: The four capscrews (26) that screw through the
back of the housing into the cylinder casting (25) hold the
casting to the pump housing. Do not remove them except
when repairing the hydraulic end.
Note: The following service procedures refer several times
to the Wanner Tool Kit. Do not try to repair the hydraulic
end of the pump without using the tools in this kit (available
from Wanner or your local distributor).
H/G-25-SD Service (Hydraulic End)
W0197A

16 H25-991-2406A
H/G-25-SD Service (Hydraulic End)
1. Remove Pump Housing
a. Remove the head of the pump, and the diaphragms, as
outlined in the Fluid End Service Section.
b. Drain the oil from the pump housing by removing the drain
plug (34). Dispose of the oil properly.
c. Set the hydraulic end of the pump face-down on the cylinder
casting (25).
d. Check the shaft for sharp burrs. Smooth any burrs, to prevent
scarring the housing seals (64) when you disassemble the
pump.
e. Alternately loosen the four capscrews (26) that secure the
housing to the cylinder casting. The piston return springs
(50) will force the cylinder casting and housing apart. Loosen
each screw one to two turns before going to the next one,
continuing until all four screws are removed.
f. Lift off the housing (30).
g. Inspect the cam and bearings (62), and the bearing race
in the rear of the housing. If the bearings are pitted or
binding, or if the housing race is worn, contact Wanner
Engineering.
2. Disassemble Pistons
a. With the pump housing removed (see above), turn the
cylinder casting over and set it on a flat surface, piston side
down.
b. With the diaphragms removed (see the Fluid End Service
Section), reinsert a follower screw (19) into the hole in one of
the valve plungers (54). Tap the screw lightly with a hammer;
the plunger (23) should slip off the valve plunger (54).
c. Repeat step “b” for the remaining pistons.
d. Each hydraulic piston assembly (50-59) can now be
disassembled. Lift the cylinder casting straight up and off
the pistons. Inspect all parts, and replace all O-rings and
any other parts that are worn or damaged.
Note: When you reassemble the hydraulic piston, use
new plungers (23). They are press-fit onto the valve
plungers (54) and are generally not reusable.
3. Reassemble Pistons
a. Drop a ball (58) into each opening in the bottom of a piston
assembly (59).
b. Insert a retaining washer (57) and O-ring (56) to hold the
ball in place.
c. Insert a valve plunger (54) into a valve cylinder (55). Slide
a spring (53) over the plunger, inside the valve cylinder.
d. Insert an O-ring (52) into a spring retainer (51).
e. Install two O-rings (52) on the valve cylinder (55).
f. Slide the assembled valve cylinder, plunger, and spring
(53-55) into the spring retainer (51).
g. Install an O-ring (56) on the spring retainer (51).
h. Slide the complete cylinder-and-retainer assembly (51-56)
into the piston assembly (59).
i. Insert a return spring (50) into the piston assembly.
j. Repeat the above procedure for the other two pistons.
4. Reassemble Pump Housing,
Shaft Assembly, and Cylinder
Casting
Note: Inspect the shaft seals (64) before continuing. If they
look damaged in any way, replace them. We recommend
changing the shaft seals whenever the camshaft assembly
is removed from the pump housing. New shaft seals will
be installed after the pump housing has been assembled
over the camshaft and fastened to the cylinder casting (see
Step 5 below). Both seals should be replaced at the same
time. Remove the seals by pounding them out from inside
the pump housing, then clean the seal bore in the housing
using emery cloth or ScotchBrite™.
a. Screw three 10-mm assembly studs (from the Wanner Tool
Kit) into three of the four threaded holes in the outer ring of
holes within the cylinder casting (25).
Thread them in all the way, from the diaphragm side of the
cylinder casting, until the head bottoms out against the face
of the cylinder casting.
Apply a slight torque to them so they will resist rotation during
the following steps.
b. Place the cylinder casting face-down on a flat surface. It will
rest on the heads of the three assembly studs just added.
This is especially important if the diaphragms and pistons
are already assembled to the cylinder casting. Never lay
the cylinder casting face-down with the weight of the
casting and/or the pump housing on the diaphragms.
c. Insert the assembled pistons (50-59) into the cylinder
casting. Check each piston to be sure all check balls (58)
are in place.
d. Note the location of the outer ring of holes in the cylinder
casting and in the pump housing flange — in particular, the
holes where capscrews (26) will be installed.
e. Stand the camshaft assembly (62) on the cylinder casting
(25), and place the seal protector (from the Wanner Tool Kit)
over the end of the shaft.
Caution: The pilot bearing must be properly nested in
the bearing race during assembly. If misaligned, the
bearing will be damaged and the pump will fail within
the first hours of operation.
f. Using grease to retain it, install the O-ring (65) and slide
the housing (30) down over the shaft and onto the threaded
studs (from step “a”). Be sure the holes in the housing and
the cylinder casting are properly aligned.
g. Install washers (6) and nuts (31) on the threaded studs, but
don’t tighten yet. You may want to insert two or more bolts
(5) into the unthreaded holes of the housing and cylinder
casting to help align the parts.
h. Alternately tighten the three nuts (31) to evenly draw the
housing down to the cylinder casting. Be sure the O-ring (65)
stays in place. Also, as you tighten the nuts keep checking
the shaft alignment by turning the shaft (use the rotator in
the Wanner Tool Kit). If the shaft begins to bind and become
difficult to turn, back off the nuts and realign the shaft. When
the pump housing is tight against the cylinder casting, you
should still be able to turn the shaft smoothly.

17 H25-991-2406A
H/G-25-SD Service (Hydraulic End)
i. After all three nuts (31) are tightened, insert a capscrew (26),
with washer (6), into the unused threaded hole in the cylinder
casting. Then remove the assembly stud, washer, and nut
that are opposite the capscrew just added, and replace them
with another capscrew and washer. Finally, remove the other
two assembly studs, which should be on opposite sides of
the pump housing from each other, and replace them with
capscrews and washers. Torque the capscrews to 25 ft-lbs
(34 N-m).
j. Turn the shaft again to check its alignment.
5. Replace Shaft Seals
a. Apply a thin film of grease on the seal protector tool (from
the Wanner Tool Kit). Slide both seals onto the tool, with the
spring side of the seals toward the open end of the tool.
Apply a heavier coat of grease between the seals and press
them together. Wipe off any excess grease that may squeeze
out onto the outside of the seals.
b. Apply a coating of LoctitehHigh-Performance Pipe Sealant
with PTFE, or a comparable product, to the outer surface
of both seals and the inside surface of the opening in the
pump housing where the seals will rest.
c. Apply a light film of grease to the drive shaft. Slide the
seal protector tool (with the two seals) over the end of the
shaft.
d. Slide the seal inserter tool (from the Wanner Tool Kit) over
the seal protector tool, and press the seals completely
into place. Tap the tool with a soft mallet to firmly seat the
seals.
6. Adjust Camshaft Endplay
a. If the three set screws (24) are in the cylinder housing (25),
remove and clean them.
b. Insert the centerbolt (1) into the hole in the center of the
cylinder housing. Turn it in to move the bearing adjusting
plate (61) and cup tight against the bearing cone.
c. Back out the centerbolt two full turns, then turn it back in
again until it is tight against the adjusting plate (61) to ensure
the proper fit.
d. Back out the centerbolt exactly 1/4 of a turn.
e. With a plastic mallet (or a regular mallet and wooden board)
to prevent damage to the shaft, rap the end of the shaft
three or four times. This will provide about .006 in. (0.15
mm) endplay in the shaft.
f. Apply removable threadlocker to the threads of the three
cleaned set screws (24), then screw them into the cylinder
casting until they contact the bearing adjusting plate (61).
g. Remove the centerbolt (1).
7. Install Plungers
Note: If the plungers (23) have been removed from the
valve plungers (54), do not reuse them. Install new ones
instead.
a. Rotate the pump shaft so the piston is in the top-dead-center
position.
b. With the nut turned back toward the hex head of the plunger
guide lifter, slide the plunger guide sleeve over the large
thread of the lifter (both the lifter and guide are included in
the Wanner Tool Kit).
c. Place a plunger on the exposed screw end of the plunger
guide lifter. The larger-diameter side of the plunger should
face the tool.
d. Screw the guide (with the plunger) into the valve plunger
(54) until tight.
e. Hold the plunger guide sleeve with a 1-in. (26-mm) open-
end wrench. Turn the hex nut down with a 3/4-in. (19 mm)
open-end wrench to force the plunger to seat on the valve
plunger. This is a press-fit — when installed, the plunger
should be tight against the shoulder of the valve plunger.
Note: Do not remove the plunger guide until the
diaphragm is installed (see below).
f. Install the diaphragm as outlined below, then repeat the
procedure for the other two plungers and diaphragms.
8. Reinstall Diaphragms
a. With the plunger guide tool still screwed into the valve
plunger (54), pull the valve plunger up until the cross-holes
in the valve plunger are exposed.
b. Insert the plunger holder (from the Wanner Tool Kit), or a
similar dowel-type object, through the holes— to hold the
plunger (23) away from the cylinder housing, and to keep
the valve plunger from turning when the diaphragm is being
installed.
c. Place the diaphragm (22) onto the plunger (23), ridge-side
out.
d. Center the diaphragm follower (21) on the diaphragm.
e. Place the O-ring (20) onto the follower screw (19).
f. Apply a small amount of threadlocker to the threads of the
follower screw.
g. Insert the follower screw (with O-ring) through the diaphragm
follower (21) and diaphragm (22), and screw it into the valve
plunger (54).
h. Hold the plunger holder, and torque the follower screw to 18
in.-lbs (2.0 N-m).
i. Repeat the above procedure for the plungers and diaphragms
of the other two cylinders.
j. Fill the reservoir with fresh oil and prime the pump, as
outlined in the Fluid End Service Section.
9. Reassemble Pump Head
Reassemble the pump head as outlined in the Fluid End Service
Section.

18 H25-991-2406A
H/G-25-SD Troubleshooting
Cavitation
• Inadequate fluid supply because:
— Inlet line collapsed or clogged
— Clogged line strainer
— Inlet line too small or too long
— Air leak in inlet line
— Worn or damaged inlet hose
— Suction line too long
— Too many valves and elbows in inlet line
• Fluid too hot for inlet suction piping system.
• Air entrained in fluid piping system.
• Aeration and turbulence in supply tank.
• Inlet vacuum too high (refer to “Inlet Calculations”, page 4).
Symptoms of Cavitation
• Excessive pump valve noise
• Premature failure of spring or retainer (14,16)
• Volume or pressure drop
• Rough-running pump
• Premature failure of diaphragms (22)
• Piston return spring failure (inside hydraulic end)
Drop in Volume or Pressure
A drop in volume or pressure can be caused by one or more
of the following:
• Air leak in suction piping
• Clogged suction line or suction strainer
• Suction line inlet above fluid level in tank
• Inadequate fluid supply
• Pump not operating at proper RPM
• Relief valve bypassing fluid
• Worn pump valve parts
• Foreign material in inlet or outlet valves
• Loss of oil prime in cells because of low oil level
• Ruptured diaphragm
• Cavitation
• Warped manifold from overpressurized system
• O - r i n g s f o r c e d o u t o f t h e i r g r o o v e s f r o m
overpressurization
• Air leak in suction line strainer or gasket
• Cracked suction hose.
• Empty supply tank
• Excessive aeration and turbulence in supply tank
• Cavitation
• Abrasives in the fluid
• Valve incompatible with corrosives in the fluid
• Pump running too fast
• Worn and slipping drive belt(s)
• Worn spray nozzle(s)
• Cracked cylinder casting
Pump Runs Rough
• Worn pump valves
• Airlock in outlet system
• Oil level low
• Wrong weight of oil for cold operating temperatures (change
to lighter weight)
• Cavitation
• Air in suction line
• Restriction in inlet/suction line
• Hydraulic cells not primed after changing diaphragm
• Foreign material in inlet or outlet valve
• Damaged diaphragm
• Fatigued or broken valve spring (14)
• Broken piston return spring (inside hydraulic end)
Premature Failure of Diaphragm
• Frozen pump
• Puncture by a foreign object
• Elastomer incompatible with fluid being pumped
• Pump running too fast
• Excess pressure
• Cavitation
• Broken piston return spring (50)
Water (or Process Fluid) in Oil
Reservoir
• Condensation
• Ruptured diaphragm
• Hydraulic cell not properly primed after diaphragm
replacement
• Frozen pump
• Diaphragm screw O-ring (20) missing or cracked
• Cracked cylinder casting
Strong Water (or Process Fluid)
Pulsations
NOTE: Small pulsations are normal in single-acting pumps
with multiple pumping chambers.
• Foreign object lodged in pump valve
• Loss of prime in hydraulic cell because of low oil level
• Air in suction line
• Valve spring (14) broken
• Cavitation
• Aeration or turbulence in supply tank

19 H25-991-2406A
Valve Wear
• Normal wear
• Cavitation
• Abrasives in the fluid
• Valve incompatible with corrosives in the fluid
• Pump running too fast
• Washer (44) missing or dislodged from position between
spring and valve
Loss of Oil
• External seepage
• Rupture of diaphragm
• Frozen pump
• Diaphragm screw O-ring (20) missing or cracked
• Worn shaft seal
• Oil drain piping or fill cap loose
• Valve plate and manifold bolts loose
Premature Failure of Valve
Spring or Retainer
• Cavitation
• Foreign object in the pump
• Pump running too fast
• Spring/retainer material incompatible with fluid being
pumped
• Excessive inlet pressure
• Washes (17, 44) missing or dislodged from position
H/G-25-SD Troubleshooting

20
Limited Warranty
Wanner Engineering, Inc. extends to the original purchaser
of equipment manufacturerd by it and bearing its name, a
limited one-year warranty from the date of purchase against
defects in material or workmanship, provided that the
equipment is installed and operated in accordance with the
recommendations and instructions of Wanner Engineering,
Inc. Wanner Engineering, Inc. will repair or replace, at its
option, defective parts without charge if such parts are
returned with transportation charges prepaid to Wanner
Engineering, Inc., 1204 Chestnut Avenue, Minneapolis,
Minnesota 55403.
This warranty does not cover:
1. The electric motors (if any), which are covered by
the separate warranties of the manufacturers of these
components.
2. Normal wear and/or damage caused by or related to
abrasion, corrosion, abuse, negligence, accident, faulty
installation or tampering in a manner which impairs normal
operation.
3. Transportation costs.
This limited warranty is exclusive, and is in lieu of any
other warranties (express or implied) including warranty
of merchantability or warranty of fitness for a particular
purpose and of any noncontractual liabilities including
product liabilities based on negligence or strict liability.
Every form of liability for direct, special, incidental or
consequential damages or loss is expressly excluded
and denied.
WANNER ENGINEERING, INC.
1204 Chestnut Avenue, Minneapolis, MN 55403
TEL: [phone] FA X: [phone]
TOLL-FREE FAX [US only]: [phone]
www.hydra-cell.com
email: [e-mail]
© 2004 Wanner Engineering, Inc. Printed in USA
H25-991-2406A 5/2004, Revised 8/2006