Installation of the Giant Industries, Inc., pump is not a
complicated procedure, but there are some basic
steps common to all pumps. The following information is to be considered as a general outline for
installation. If you have unique requirements, please
contact Giant Industries, Inc. or your local distributor
for assistance.
1. The pump should be installed flat on a base to a
maximum of a 15 degree angle of inclination to ensure
optimum lubrication.
2. The inlet to the pump should be sized for the flow rate
of the pump with no unnecessary restrictions that can
cause cavitation. Teflon tape should be used to seal all
joints. If pumps are to be operated at temperatures in
excess of 1600 F, it is important to insure a positive head
to the pump to prevent cavitation.
3. The discharge plumbing from the pump should be
properly sized to the flow rate to prevent line pressure
loss to the work area. It is essential to provide a safety
bypass valve between the pump and the work area to
protect the pump from pressure spikes in the event of a
blockage or the use of a shut-off gun.
4. Use of a dampener is necessary to minimize
pulsation at drive elements, plumbing, connections,
and other system areas. The use of a dampener with
Giant Industries, Inc. pumps is optional, although
recommended by Giant Industries, Inc. to further
reduce system pulsation. Dampeners can also
reduce the severity of pressure spikes that occur in
systems using a shut-off gun. A dampener must be
positioned downstream from the unloader.
5. Crankshaft rotation on Giant Industries, Inc.
pumps should be made in the direction designated by
the arrows on the pump crankcase. Reverse rotation
may be safely achieved by following a few guidelines
available upon request from Giant Industries, Inc.
Required horsepower for system operation can be
obtained from the charts on pages 3-5 and page 8.
6. Before beginning operation of your pumping
system, remember: Check that the crankcase and
seal areas have been properly lubricated per recommended schedules. Do not run the pump dry for
extended periods of time. Cavitation will result in
severe damage. Always remember to check that all
plumbing valves are open and that pumped media
can flow freely to the inlet of the pump.
Finally, remember that high pressure operation in a pump system has many advantages. But, if it is used carelessly
and without regard to its potential hazard, it can cause serious injury.
IMPORTANT OPERATING CONDITIONS
Failure to comply with any of these conditions invalidates the warranty.
1. Prior to initial operation, add oil to the crankcase so
that oil level is between the two lines on the oil dipstick.
DO NOT OVERFILL.
2. Pump operation must not exceed rated pressure, volume,
or RPM. A pressure relief device must be installed in the
discharge of the system.
Use SAE 80-90W or Giant’s p/n 01154 or ISO
VG220 industrial gear lube oil
Crankcase oil should be changed after the first 50
hours of operation, then at regular intervals of 500 hours
or less depending on operating conditions.
3. Acids, alkalines, or abrasive fluids cannot be pumped
unless approval in writing is obtained before operation from
Giant Industries, Inc.
4. Run the pump dry approximately 10 seconds to drain the
water before exposure to freezing temperatures.
2
Specifications
ModelS P420A, P420A-0011, P420A-0021
U.S.(Metric)
Volume................................................................ Up to 12.9 GPM ................. (48.8 LPM)
Discharge Pressure.............................................. Up to 2175 PSI ................... (150 bar)
Inlet Pressure....................................................... -4.35 to 145 PSI.................. (-.3 to 10 bar)
Consult the factory for special requirements that must be met if the pump is
to operate beyond one or more of the limits specified above.
NOTES:
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 fill and the oil
drain plugs, also. Refer to the repair instructions as necessary for
the proper assembly sequence.
Consult the factory for special requirements that must be met if the pump is
to operate beyond one or more of the limits specified above.
NOTES:
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 fill and the oil
drain plugs, also. Refer to the repair instructions as necessary for
the proper assembly sequence.
Consult the factory for special requirements that must be met if the pump is
to operate beyond one or more of the limits specified above.
NOTES:
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 fill and the oil
drain plugs, also. Refer to the repair instructions as necessary for
the proper assembly sequence.
Consult the factory for special requirements that must be met if the pump is
to operate beyond one or more of the limits specified above.
NOTES:
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 fill 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 0.0074.
To find specific outputs at various RPM,
use the formula: GPM = 0.0074 x RPM
HORSEPOWER RATINGS:
The rating shown are the power
requirements for the
engine power outputs must be
approximately twice the pump
power requirements shown above.
We recommend a 1.15 service factor
be specified when selecting an
electric motor as the power source.
To compute specific pump horse
power requirements, use the
following formula:
HP = (GPM X PSI) / 1450
pump. Gas
8
Repair Instructions P420/P420-0011/P420-0021/P422/P423 and P425
Note: Always take time to lubricate all metal and nonmetal parts with a light film of oil before reassembly. This step will ensure
proper fit, at the same time protecting the pump nonmetal parts (i.e., the elastomers) from cutting and scoring.
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 adaptors (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 fitted 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 adaptor (20).
Check O-rings (21).
9
Repair Instructions P420/P420-0011/P420-0021/P422/P423 and P425
IMPORTANT! Care must be
taken that glue does not get
between the plunger pipe (16B)
and centring sleeve (16C). The
plunger pipe should not be
strained by eccentric tightening
of the tension screw or through
damage to front surface of
plunger, otherwise it is liable to
fracture.
9) Check surfaces of plunger
(16). Damaged surfaces
cause accelerated seal wear.
Deposits of all kinds must be
removed from the plungers.
IMPORTANT! Plunger
surfaces are not to be
damaged. If there are lime
deposits in the pump, care
must be taken that the dripreturn bore in parts (25)
and (26) ensure trouble-free
drip-return.
11) After installation of high
pressure seals (23), place seal
adaptor (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
firmly. Replace the 8 socket
head cap screws (34) and
tighten to 30 ft.-lbs.(47 NM)
in a crossing pattern
(as shown below).
10) If the plunger pipe (16B), or
oil seal (19) is worn, remove
tension screw (16D) and remove along with plunger
pipe (16B). Check and clean
plunger surface (16A), check
oil scraper (16H). Remove
the gear seal adapter (20A)
and, if necessary, replace oil
seals with seal lips facing
crankcase (1).Cover thread
of tension screw (16D) with
a thin film of Loctite and
tighten carefully to 22 ft.-lbs.
(30NM).
8
4
1
76
2
5
3
Torque Specifications P420/P420-0011/P420-0021/P422/P423 and P425
PositionItem#DescriptionU.SMetric
15A07311Screw with Washer97 in.-lbs.11 NM
16D08399Tensioning Screw22 ft.-lbs.30 NM
Contact Giant Industries for service school information. Phone: (419) 531-4600
10
PUMP SYSTEM MALFUNCTION
MALFUNCTIONCAUSEREMEDY
The Pressure and/Worn packing sealsReplace packing seals
or the DeliveryBroken valve springReplace spring
DropsBelt slippageTighten or Replace belt
Worn or Damaged nozzleReplace nozzle
Fouled discharge valveClean valve assembly
Fouled inlet strainerClean strainer
Worn or Damaged hoseRepair/Replace hose
Worn or Plugged relief valve on pumpClean, Reset, and Replace worn parts
CavitationCheck suction lines on inlet of
pump for restrictions
UnloaderCheck for proper operation
Water in crankcaseHigh humidityReduce oil change interval
Preventative Maintenance Check-List & Recommended Spare Parts List
CheckDailyWeekly50hrsEvery Every Every
500 hrs 1500 hrs 3000 hrs
Oil Level/QualityX
Oil LeaksX
Water LeaksX
Belts, PulleyX
PlumbingX
Recommended Spare Parts
Oil Change (1 Gallon) p/n 1154X 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 lit)
Valve Spare Parts (1 kit/pump) X
(See page 7 for kit list)
11
Dimensions - P420/P420-0011/P420-0021/P422/P423 and P425 - 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:
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:
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.
1.For portable pressure washers and self-service car wash applications, the discharge manifolds
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 five years from
the date of shipment for all pumps used in NON-SALINE, clean water applications.
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.
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 modifications made by the customer or third party.
6.The operation of pumps and or accessories exceeding the specifications set forth in the
Operations Manuals provided by Giant Industries, Inc.
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 AND EXCLUDED BY THE MANUFACTURER.