Required NPSH refers to water (specic weight
1kg/dm3) at maximum permissible pump revolu-
tions.
Operation and Maintenance
Check oil level prior to starting and ensure
trouble-free water supply.
Important! If there is a danger of frost, the
water in the pump and in the pump ttings (particularly the unloader valve) must be emptied.
The second discharge port can also be used
and the pump run “dry” for 1-2 minutes for this
purpose.
Oil: Use only 30.4 ounces (0.9 liters) of ISO VG
220 GL4 (e.g. Aral Degol BG220) or SAE 90
GL4 gear oil (Giant’s part number 01154).
Initial oil change after 50 operating hours and
then every 500 hours, after 1 year if used less.
Caution when operating in damp places or
with high temperature uctuations. Oil must
be changed immediately should condensate
(frothy oil) occur in the gear box.
When the pump is in operation, the drive
shaft end and the coupling must be enclosed by a protective cover or a coupling
bell.
Pressure in the discharge line and pump
must be at zero before any maintenance to
the pump takes place. Shut off suction line.
Disconnect fuses to ensure that the driving
motor does not get switched on accidently.
Make sure that all parts on the pressure
side of the unit are vented before starting
the pump. In order to prevent air, or an airwater mixture being absorbed and to prevent cavitation occurring, the pump NPSHR
(=suction head) and water temperature
must be respected.
Cavitation and/or compression of gases
lead to uncontrollable pressure-kicks
which can ruin pump and unit parts and
also be dangerous to the operator or
anyone standing nearby.
NPSH values must be observed.
Maximum input pressure 145 PSI (10 bar)
maximum suction head -4.35 PSI (-0.3 bar).
Make sure that suction pulsation is sufciently
dampened - water column resonance must be
avoided.
Important! If the pump is not used for a long
period of time, it is possible the seals (23/23B)
could become hard or brittle thus causing the
pump to leak when put into operation.
If this is the case, we recommend these seals
be replaced every 4 years.
Safety Rules
A safety valve is to be installed in accordance
with the guidelines for liquid spraying units so
that the admissible operating pressure cannot be exceeded by more than 10%. Pump
operation without a safety valve as well as any
excess in temperature or speed limits automatically voids the warranty.
Giant Plunger Pumps are suitable for pumping clean water and other non-aggressive or
non-abrasive media with a specic weight
similar to water.
Before pumping other liquids - especially
ammable, explosive and toxic media
- the pump manufacturer must be consulted with regard to the resistance of
the pump material. It is the responsibility of the equipment manufacture and/
or operator to ensure that all pertinent
safety regulations are adhered to.
2
Specications
Model P420A-5100
U.S. (Metric)
Volume.......................................................................Up to 12.8 GPM ............................(48.4 LPM)
Discharge Pressure ..................................................Up to 2200 PSI ................................ (150 bar)
Power Required .........................................................19.2 BHP ........................................... 14.3 kW
Inlet Pressure ............................................................-4.35 to 145 PSI ......................(-0.3 to 10 bar)
NPSHR ...........................................................................30.5 ft. of head ............................ 9.3 mWs
1
Consult the factory for special requirements that must be met if the
pump is to operate beyond one or more of the limits specied above.
1
NOTE:
In order to drive the pump from the side opposite the present shaft extension, simply remove the valve casing from the crankcase and rotate the pumps 180 degrees to the desired
position. Be certain to rotate the seal case (item #20) as well, so that the weep holes are
down at the six o’clock position. Exchange the oil ll and the oil drain plugs, also. Refer to
the repair instructions as necessary for the proper assembly sequence.
The theoretical gallons per revolution
(gal/rev) is 0.00883. To nd specic
outputs at various RPM, use the formula:
GPM = 0.00883 x RPM
1500
PSI
1700
PSI
2200
PSI
HORSEPOWER RATINGS:
The rating shown are the power
requirements for the pump. Gas
engine power outputs must be
approximately twice the pump
power requirements shown above.
We recommend a 1.15 service factor be specied when selecting an
electric motor as the power source.
To compute specic pump horsepower requirements, use the following formula:
HP = (GPM X PSI) / 1450
3
Specications
Model P422-5100
U.S. (Metric)
Volume...........................................................................Up to 9.9 GPM ...........................(37.3 LPM)
Discharge Pressure ...................................................... Up to 2600 PSI ..............................(180 bar)
Power Required ............................................................. 17.7 BHP ......................................... 13.2 kW
Inlet Pressure ................................................................-4.35 to 145 PSI ....................(-0.3 to 10 bar)
NPSHR .......................................................................... 22.3 ft. of head ............................... 6.8 mWs
1
Consult the factory for special requirements that must be met if the
pump is to operate beyond one or more of the limits specied above.
1
NOTE:
In order to drive the pump from the side opposite the present shaft extension, simply
remove the valve casing from the crankcase and rotate the pumps 180 degrees to the
desired position. Be certain to rotate the seal case (item #20) as well, so that the weep
holes are down at the six o’clock position. Exchange the oil ll and the oil drain plugs,
also. Refer to the repair instructions as necessary for the proper assembly sequence.
The theoretical gallons per revolution
(gal/rev) is 0.00679. To nd specic
outputs at various RPM, use the
formula: GPM = 0.00679 x RPM
HORSEPOWER RATINGS:
The rating shown are the power
requirements for the pump. Gas
engine power outputs must be
approximately twice the pump
power requirements shown above.
We recommend a 1.15 service factor be specied when selecting an
electric motor as the power source.
To compute specic pump horsepower requirements, use the
following formula:
HP = (GPM X PSI) / 1450
4
Specications
Model P423-5100
U.S. (Metric)
Volume............................................................................Up to 8.2 GPM ......................... (31.1 LPM)
Discharge Pressure ........................................................ Up to 3000 PSI ............................ (200 bar)
Power Required .............................................................. 16.4 BHP ........................................ 12.2 kW
Inlet Pressure .................................................................-4.35 to 145 PSI .................. (-0.3 to 10 bar)
NPSHR ........................................................................... 21 ft. of head .................................6.4 mWs
1
Consult the factory for special requirements that must be met if the
pump is to operate beyond one or more of the limits specied above.
1
NOTE:
In order to drive the pump from the side opposite the present shaft extension, simply
remove the valve casing from the crankcase and rotate the pumps 180 degrees to the
desired position. Be certain to rotate the seal case (item #20) as well, so that the weep
holes are down at the six o’clock position. Exchange the oil ll and the oil drain plugs,
also. Refer to the repair instructions as necessary for the proper assembly sequence.
The theoretical gallons per revolution
(gal/rev) is 0.00566. To nd specic
outputs at various RPM, use the
formula: GPM = 0.00566 x RPM
HORSEPOWER RATINGS:
The rating shown are the power
requirements for the pump. Gas
engine power outputs must be approximately twice the pump
power requirements shown above.
We recommend a 1.15 service factor be specied when selecting an
electric motor as the power source.
To compute specic pump horsepower requirements, use the following formula:
HP = (GPM X PSI) / 1450
5
EXPLODED VIEW - P400-5100 Series - 22mm & 25mm
6
P420A-5100 / P422-5100 / P423-5100 and P425-5100 SPARE PARTS LIST
A = P420A-5100 B = P425-5100 C = P422-5100 D = P423-5100
ITEM PART DESCRIPTION QTY.
1 08377 Crankcase 1
2 08378 Oil Fill Plug with Gasket 1
3 06479 Crankcase cover 1
3A 07186 Oil Sight Glass w/ Gasket 1
4 08380 O-Ring 1
5 07109-0400 Oil Drain Plug 1
5A 06015 O-Ring 1
5B 08092-0100 Plug with Gasket 1
6 08093 Screw 4
6A 01011-0400 Spring Washer 4
7 04739 Bearing Cover, Open 1
8 05291 Bearing Cover, Closed 1
8A 05292 Shim 1-3
8B 05293 Shim (May not be present) 1
8C 05764 Shim (May not be present) 1-2
9 01016 O-Ring 2
10 07114-0100 Screw with Washer 8
10A 01011-0400 Spring Washer 8
11 07459 Radial Shaft Seal 1
12 05350 Taper Roller Bearing 2
13 04741 Crankshaft (A and C) 1
13 04740 Crankshaft (B and D) 1
13A 04742 Spacer Ring 1
14 08091 Fitting Key 1
15 08390 Connecting Rod Assembly 3
15A 05349 Connecting Rod Screw 3
15B 05348 Adapter Sleeve 3
16 05351-0100 Plunger Assy., 25mm, (A and B)
For items 16A-16H 3
16 05353-0100 Plunger Assy., 22mm, (C and D)
For items 16A-16H 3
16A 08384-0600 Plunger Base 3
16B 08398 Plunger Pipe, 25mm (A and B) 3
16B 06247 Plunger Pipe, 22mm (C and D) 3
ITEM PART DESCRIPTION QTY.
16D 08399-0100 Tensioning Screw 3
16E 07023-0001 O-Ring, Viton 3
16F 07203 Backup Ring 3
16G 07161-0100 Seal Ring 3
16H 06431 Flinger 3
17 06790 Crosshead Pin 3
19 05444 Oil Seal 3
20 05443-0100 Seal Case (A and B) 3
20 05592-0100 Seal Case (C and D) 3
21 07266 O-Ring 3
23 12254 V-Sleeve, 25mm (A and B) 3
23 06249 V-Sleeve with Support Ring,
22mm (C and D) 3
23A 06251-0100 Spacer Ring (C and D) 3
23B 12255 Weep Seal (A and B) 3
23B 13390 Weep Seal (C and D) 3
24 08376 Pressure Ring (A and B) 6
24 06252 Pressure Ring (C and D) 3
25 06373 Weep Return Ring (A and B) 3
25 06254-0100 Weep Return Ring (C and D) 3
26 06255-5000 Manifold 1
27A 08408-0100 Valve Assembly 6
27 08370-0100 Valve Seat 6
28 06791-0100 Valve Plate 6
29 06377-0100 Valve Spring 6
30 08372 Valve Spring Retainer 6
31 07212-0001 O-Ring, Viton 6
32 08373-0600 Plug 6
33 07214 O-Ring 6
34 08396-0100 Hexagon Screw 8
36 13150-0100 Plug, 3/4” BSP 1
36A 06808 Steel Seal Ring, 3/4” 1
37 13321-0100 Plug, 1” BSP 1
P420A-5100 / P422-5100 / P423-5100 and P425-5100 Repair Kits
Plunger Packing Kits
P420-5100, P425-5100 - # 09653
Item Part # Description Qty
21 07266 O-Ring 3
23 12254 V-Sleeve 3
23B 12255 Weep Seal 3
24 08376 Pressure Ring 6
P422-5100, P423-5100 - # 09654
Item Part # Description Qty
21 07266 O-Ring 3
23 06249 V-Sleeve 3
23B 13390 Weep Seal 3
24 06252 Pressure Ring 3
NPSHR ........................................................................... 26.2 ft. of head .............................8.0 mWs
1
Consult the factory for special requirements that must be met if the
pump is to operate beyond one or more of the limits specied above.
1
NOTE:
In order to drive the pump from the side opposite the present shaft extension, simply
remove the valve casing from the crankcase and rotate the pumps 180 degrees to the
desired position. Be certain to rotate the seal case (item #20) as well, so that the weep
holes are down at the six o’clock position. Exchange the oil ll and the oil drain plugs,
also. Refer to the repair instructions as necessary for the proper assembly sequence.
The theoretical gallons per revolution
(gal/rev) is 0.00738. To nd specic
outputs at various RPM, use the
formula: GPM = 0.00738 x RPM
HORSEPOWER RATINGS:
The rating shown are the power
requirements for the pump. Gas
engine power outputs must be
approximately twice the pump
power requirements shown
above.
We recommend a 1.15 service
factor be specied when selecting an electric motor as the power source. To compute specic
pump horsepower requirements,
use the following formula:
HP = (GPM X PSI) / 1450
8
Repair Instructions - P420A-5100/P422-5100/P423-5100 and P425-5100
1) With a socket wrench,
remove the three discharge valve plugs and
three inlet valve plugs
(32). Inspect the o-ring
(33) for wear and replace
if damaged.
4) Remove the O-ring (31).
Inspect all parts for wear
and replace as necessary.
Apply one drop of loctite
243 to the valve plugs (32)
and tighten to 107 ft.-lbs.
(145 NM).
2) Using needle nose pliers, remove the inlet and
discharge valve assemblies (27A). Note: It
may become neccesary
to remove the valve seat
(27) from the valve casing
using a slidehammer.
5) Use a 8mm allen wrench
to remove the 8 socket
head cap screws (34).
Carefully slide the valve
casing (26) out over the
plungers.
3) By inserting a small screw
driver between the valve
seat (27) and the valve
spring retainer (30), the
valve assembly can be
separated.
6) Remove seal adapters
(20) and weep return rings
(25) from the valve casing.
7) Remove the pressure
rings (24) and v-sleeves
(23 - Note: P422 & P423
pumps have a support
ring) from the valve casing (26).
IMPORTANT! The grooved
seal (23) on the high-pressure
side is to be tted carefully into
the valve casing (26) using a
screwdriver. Under no circumstances must the seal surface
in the valve casing or the seal
lip be damaged.
8) Remove the weep grooved
seal (23 or 23B) together
with pressure ring (24 P420 and P425 only) out
of the seal case (20).
Check O-rings (21).
9
Repair Instructions
P420A-5100 / P422-5100 / P423-5100 and P425-5100
IMPORTANT!
Plunger surfaces are not
to be damaged. If there
are lime deposits in the
pump, care must be
taken that the drip-return
bore in parts (25) and
(26) ensure trouble-free
drip-return.
9) Check surfaces of plunger
(16). Damaged surfaces
cause accelerated seal
wear. Deposits of all kinds
must be removed from the
plungers.
10) If the plunger pipe (16B), is
damaged or worn, remove
tension screw (16D) and
plunger pipe (16B). Check
and clean plunger surface
(16A) and check inger
(16H). Cover thread of
tension screw (16D) with a
thin lm of Loctite 243 and
tighten carefully to 22 ft.lbs. (30NM).
11) If oil leaks under under the
plunger (16), the oil seals
(19) need to be replaced.
Remove oil plug (5) and
drain oil. With the valve
casing (26) and seal case
(20) removed (ref. instructions #5 & 6), and plunger
disassembled (ref. #10),
carefully pry out the oil
seal with a at screwdriver
and replace it with a new
one. Make sure that the oil
seal groove faces inward
towards the oil.
12) After installation of high
pressure seals (23), place
seal case (20) with weep
seals & pressure ring
installed, weep return
ring (25) and high pressure weep return ring (24)
over plungers. Slide valve
casing over plungers and
seat rmly. Replace the 8
socket head cap screws
(34) and tighten to 22
ft.-lbs.(40 NM) in a crossing pattern (as shown at
right).
4
8
1
76
2
5
3
NOTE: Be careful not
to score the crankcase
guides where the oil seal
sits and where the plunger
base (16A) moves through
the crankcase (1).
Pump Torque Specications/Lubrication
Position Item# Description Lubrication Info U.S (Metric)
The Pressure and/ Worn packing seals Replace packing seals
or the Delivery Broken valve spring Replace spring
Drops Belt slippage Tighten or Replace belt
Worn or Damaged nozzle Replace nozzle
Fouled discharge valve Clean valve assembly
Fouled inlet strainer Clean strainer
Worn or Damaged hose Repair/Replace hose
Worn or Plugged relief valve on pump Clean, Reset, and Replace worn parts
Cavitation Check suction lines on inlet of pump for restrictions
Unloader Check for proper operation
Water in crankcase High humidity Reduce oil change interval
Operation with Inlet restriction Check system for stoppage, air
Pressure Drop leaks, correctly sized inlet
plumbing to pump
Accumulator pressure Recharge/Replace accumulator
Unloader Check for proper operation
Cavitation Check inlet lines for restrictions
and/or proper size
Pressure Drop at Gun Restricted discharge plumbing Re-size discharge plumbing to ow rate of pump
Excessive Worn plungers Replace plungers
Leakage Worn packing/seals Adjust or Replace packing seals
Excessive vacuum Reduce suction vacuum
Cracked plungers Replace plungers
Inlet pressure too high Reduce inlet pressure
High Crankcase Wrong Grade of oil Giant oil is recommended
Temperature Improper amount of oil in crankcase Adjust oil level to proper amount
Preventative Maintenance Check-List & Recommended Spare Parts List
Check Daily Weekly 50hrs Every Every Every
500 hrs 1500 hrs 3000 hrs
Oil Level/Quality X
Oil Leaks X
Water Leaks X
Belts, Pulley X
Plumbing X
Recommended Spare Parts
Oil Change (p/n 1154) X X
Seal Spare Parts (1 kit/pump) X
(See page 7 for kit list)
Oil Seal Kit (1 kit/pump) X
(See page 7 for kit list)
Valve Spare Parts (1 kit/pump) X
(See page 7 for kit list)
11
Dimensions
P420A-5100/P422-5100/P423-5100 and P425-5100 - Inches (mm)
GIANT INDUSTRIES LIMITED WARRANTY
Giant Industries, Inc. pumps and accessories are warranted by the manufacturer to be free from defects in
workmanship and material as follows:
1. For portable pressure washers and self-service car wash applications, the discharge manifolds
2. One (1) year from the date of shipment for all other Giant industrial and consumer pumps.
3. Six (6) months from the date of shipment for all rebuilt pumps.
4. Ninety (90) days from the date of shipment for all Giant accessories.
This warranty is limited to repair or replacement of pumps and accessories of which the manufacturer’s evaluation shows were defective at the time of shipment by the manufacturer. The following items are NOT covered
or will void the warranty:
1. Defects caused by negligence or fault of the buyer or third party.
2. Normal wear and tear to standard wear parts.
3. Use of repair parts other than those manufactured or authorized by Giant.
4. Improper use of the product as a component part.
5. Changes or modications made by the customer or third party.
6. The operation of pumps and or accessories exceeding the specications set forth in the Opera-
will never fail, period. If they ever fail, we will replace them free of charge. Our other pump parts,
used in portable pressure washers and in car wash applications, are warranted for ve years
from the date of shipment for all pumps used in NON- SALINE, clean water applications.
tions Manuals provided by Giant Industries, Inc.
Liability under this warranty is on all non-wear parts and limited to the replacement or repair of those products
returned freight prepaid to Giant Industries which are deemed to be defective due to workmanship or failure of
material. A Returned Goods Authorization (R.G.A.) number and completed warranty evaluation form is required
prior to the return to Giant Industries of all products under warranty consideration. Call (419)-531-4600 or fax
(419)-531-6836 to obtain an R.G.A. number.
Repair or replacement of defective products as provided is the sole and exclusive remedy provided hereunder
and the MANUFACTURER SHALL NOT BE LIABLE FOR FURTHER LOSS, DAMAGES, OR EXPENSES,
INCLUDING INCIDENTAL AND CONSEQUENTIAL DAMAGES DIRECTLY OR INDIRECTLY ARISING FROM
THE SALE OR USE OF THIS PRODUCT.
THE LIMITED WARRANTY SET FORTH HEREIN IS IN LIEU OF ALL OTHER WARRANTIES OR REPRESENTATION, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY WARRANTIES OR MERCHANTABILITY
OR FITNESS FOR A PARTICULAR PURPOSE AND ALL SUCH WARRANTIES ARE HEREBY DISCLAIMED