Giant GP5128 Instruction Manual

Contents:
Installation Instructions: page 2
Pump Specications: page 3
Exploded View: page 4
Parts List: page 5
Kits/Torque Specs: page 5
Repair Instructions: page 6
Dimensions: page 7
Warranty Information back page
Model
GP5128
Triplex Ceramic
Plunger Pump
Operating Instructions /
Manual
Updated 07/18

2
INSTALLATION INSTRUCTIONS
Figures for speed (rpm) and pressure apply to
interval operation with cold water.
For continual operation, the speed of all pump
models must be limited to 700 rpm and the
max. operating pressure reduced by 10%.
Required NPSH refers to water: Specic weight
1kg/dm3, viscosity 1°E at max. permissible revo-
lutions.
Operation and Maintenance
Check oil level prior to starting and ensure trou-
ble-free water supply. Oil: Use only 1.2 gallons
(4.6 liters) of Industrial Gear Lube Oil (Giant p/n
01154) or ISO VG 220 (e.g. Aral Degol BG220)
or SAE 90 gear oil.
Initial change after 50 operating hours and then
every 500 operating hours.
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.
Keep NPSH under control.
Max. input pressure 145 PSI (10 bar), max. suc-
tion head -4.35 PSI (-0.3 bar).
Safety Rules
Pump operation without safety valve as well
as any excess in temperature or speed limits
automatically voids the warranty. The safety
valve must be regulated in accordance with
the guidelines for liquid spraying units so that
the admissible operating pressure can not be
exceeded by more than 10%.
When the pump is in operation, the open shaft
end must be covered up by a shaft protector
(21), the driven shaft side and coupling by a
contact-protector.
Pressure in discharge line and in pump must
be at zero before any maintenance to the pump
takes place. Close up 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 and relled, with pressure at
zero, before starting the pump.
In order to prevent air, or an air/water-mixture
being absorbed and to prevent cavitation occur-
ing, te pump-npshr, positive suction head and
water temperature must be kept under control.
Cavitation and/or compression of gases lead
to uncontrollable pressure-kicks which can
ruin pump and unit parts and also be dan-
gerous to the operator or anyone standing
nearby.
Giant plunger pumps are suitable for pump-
ing clean water and other non-agressive or
abrasive media with a specic weight similar to
water.
Before pumping other liquids - especially
inammable, explosive and toxic media - the
pump manufacturer must under all circum-
stances be consulted with regard to the
resistance of the pump material. It is the re-
sponsibility of the equipment manufacturer
and/or operator to ensure that all pertinent
safety regulations are adhered to.

3
U.S. ......................... (Metric)
Volume.......................................................... 20.6 GPM .............. 78.0 LPM
Discharge Pressure......................................4060 PSI ................. 280 bar
Power Required............................................56.0 BHP................. 41.8 kW
Speed (Continuous)...................................... ................................ 1000 RPM
Inlet Pressure (maximum) ............................-4.35 to145 PSI ...... -0.3 to 10 bar
Plunger Diameter..........................................1.1” .......................... 28 mm
Crankshft Stroke...........................................1.81” ........................ 46 mm
Crankshaft Diameter.....................................1.38” ........................ 35 mm
Crankshaft Mounting ..................................................................... Either side
Shaft Rotation................................................................................ Top of pulley towards manifold
Temperature of Pumped Fluids ....................Up to 140oF ............. (60oC)
Inlet Ports ...................................................................................... (3) 1-1/2” NPT
Discharge Ports............................................................................. (2) 1” NPT
Weight ..........................................................179 lbs. ................... (81 kg)
Crankcase Oil Capacity................................1.2 Gal. ................... (4.6 liter)
Fluid End Material......................................... ................................ Nickel-Plated Spheroidical Cast Iron
Specications
Model GP5128
Consult the factory for special requirements that must be met if the pump is to
operate beyond one or more of the limits specied above.
PULLEY INFORMATION
Pulley selection and pump speed are based on
a 1725 RPM motor and “B” section belts. When
selecting desired GPM, allow for a ±5% tolerance
on pumps output due to variations in pulleys, belts
and motors among manufacturers.
1. Select GPM required, then select appropriate
motor and pump pulley from the same line.
2. The desired pressure is achieved by selecting
the correct nozzle size that corresponds with the
pump GPM.
HORSEPOWER INFORMATION
Horsepower ratings shown are the power re-
quirements for the pump. Gas engine power
outputs must be approximately twice the pump
power requirements shown above.
We recommend that a 1.15 service factor be speci-
ed when selecting an electric motor as the power
source. To compute specic pump horsepower
requirements, use the following formula:
(GPM X PSI) / 1450 = HP
GP5128 Horsepower Requirements
RPM GPM 1000 PSI 2000 PSI 3000 PSI 4060 PSI
600 12.4 8.6 17.1 25.7 34.7
700 14.4 9.9 19.9 29.8 40.3
800 16.5 11.4 22.8 34.1 46.2
900 18.5 12.8 25.5 38.3 51.8
1000 20.6 14.2 28.4 42.6 57.7

4
GP5128 Exploded View

5
ITEM PART DESCRIPTION QTY.
1 13266 Crankcase 1
2 13000 Oil Filler Plug Assembly 1
3 05943 Oil Sight Glass Assembly 1
4 13267 Crankcase Cover 1
5 13268 O-Ring 1
8 07105 Oil Dip Stick 1
9 01009 O-Ring, Dip Stick 1
10 07008 Inner Hexagon Screw 4
11 06725 Spring Washer 4
12 07703 Drain Plug, 3/4” BSP 1
13 07704 Gasket, Drain Plug 1
14 13271 Bearing Cover 2
15 13272 Radial Shaft Seal 2
16 08182 O-Ring 2
17 13358 Hexagon Screw 8
18 06725 Spring Washer 8
20 13206 Taper Roller Bearing 2
20A* 13207 Shim, 0.1mm 1-5
20B* 04723 Shim, 0.15mm 1-5
20C* 04724 Shim, 0.2mm 1-5
21 13273 Shaft Protector 1
22 13274 Crankshaft 1
23 13275 Fitting Key 1
24 13276 Connecting Rod Assembly 3
25 13279 Crosshead Assembly 3
28 13281 Crosshead Pin 3
29A 07125 Centering Sleeve 3
29B 13220 Plunger Pipe 3
29C 13031 Tensioning Screw 3
29D 07755 Copper Ring 3
30 13282 Oil Scraper 3
*May not be present
GP5128 Spare Parts List
ITEM PART DESCRIPTION QTY.
30A 05889 Washer for Drip Shield 3
31 13284 Radial Shaft Seal 3
35 04286 Seal Sleeve 3
35B 08183 O-Ring 3
36 13228 Grooved Ring 3
37 04287 Seal Case 3
37A 07700 O-Ring 6
39 13197 Pressure Ring 3
40 13115 V-Sleeve 6
41 13198 Sleeve Support Ring 3
42 07173 Tension Spring 3
43 04288-NPT Valve Casing 1
44 07150 O-Ring 6
45 07109 Plug, 1/2” BSP 1
45A 06272 Copper Seal Ring, 1/2” 1
46 07060 Valve Assembly 6
46A 07064 Valve Seat 6
46B 07063 Valve Plate 6
46C 07062-0100 Valve Spring 6
46D 07066 Spacer Pipe 6
47 04295 Spacer Ring 3
48 04289 Plug 3
48A 07008 Inner Hexagon Screw 12
48B 13012 O-Ring 3
48C 06078 Tension Spring 3
49 13339 Inner Hexagon Screw 8
52 13362 Disc for Crankshaft 1
53 13358 Hexagon Screw 1
54 06626 Plug, 1” NPT 1
55 06627 Plug, 1-1/2” NPT 2
56 07623 Eye Bolt 1
57 04334 Drip Pan 1
GP5128 Repair Kits
Plunger Packing Kit - #09761
Item Part# Description Qty.
35B 08183 O-Ring 3
36 13228 Grooved Ring 3
37A 07700 O-Ring 6
40 13115 V-Sleeve 6
Valve Assembly Kit - #09762
Item Part # Description Qty.
46 07060 Valve Assembly 6
48B 13012 O-Ring 3
Oil Seal Kit - #09230
Item Part # Description Qty.
31 13284 Oil Seal 3

6
To Check Valves
Remove inner hexagon screw (48A) and remove plugs (48) with a screwdriver. Check O-rings on plugs (48B).
Pull out tension spring (48C). Take spacer pipe (46D) together with the discharge valve out of the valve casing
using a clipring pliers or a ø22 extractor tool. Remove the next exposed spacer pipe and suction valve as already
described. Remove the valve seats (46A) from the spacer pipes by lightly tapping the valve plate (46B) from
above with a plastic rod. Check sealing surfaces and replace worn parts.
When reassembling, use new O-rings if possible and oil them before installing.
Tighten inner hexagon screws (48A) to 35 Ft-Lbs (47NM).
To Check Seals and Plunger Pipe
Loosen the 8 nut and pull off valve casing to the front. Pull seal sleeves (35) out of guides in crankcase and over
the plunger pipe (29B). Pull support ring (41), sleeves (40) and pressure ring (39) out of seal sleeve.
Check plunger surfaces, sleeves (40) and grooved rings (36). Replace worn parts.
If the plunger pipe is worn out, loosen tension screw (29C) and pull off plunger pipe to the front. Clean contact
surfaces of plunger (25) thoroughly. Then place new plunger pipe carefully through the oiled seals into the seal
case. Check O-rings (35A, 35B) on seal sleeves and replace worn O-rings. Then push seal sleeve together with
plunger pipe into the crankcase guide. Turn gear carefully until plunger (25) comes up against the plunger pipe.
Put a new copper gasket (29D) onto the tension screw (29C). Cover the thread of tension screw and the gasket
with glue and tighten to 26 Ft.-lbs. (35NM).
Important! Care must be taken that no glue gets between the plunger pipe (29B) and the centering sleeve
(29A). The plunger pipe should not be strained by eccentric tightening of the tension screw or through damage
to front of surface of plunger, otherwise it will probably break. Tighten the inner screws (49) for the valve casing
evenly to 74-89 Ft.-Lbs. (100-120NM).
To Dismantle Gear
Drain oil after dismantling valve case and plunger pipes and screw off crankcase cover (4) and bearing cover
(14).
Loosen con rod screws (24), push stem of con rod as far as possible into the crosshead guide and carefully
push out the radial shaft seals (31).
Important! Connecting rods are marked for identication. Do not twist con rod halves. Con rod is to be reinstalled
in the same position on shaft journals.
While slightly turning the crankshaft, hit it out carefully to one side with a rubber hammer.
Important! Do not bend con rod shank. Finally, check surfaces of shaft, con rod, crosshead and plungers (25)
as well as radial shaft seals (15, 31) and taper roller bearings (20).
To Reassemble
Using a soft tool, press in the outer bearing ring until it lines up with the outer edge of the bearing hole. Remove
bearing cover together with shaft ring and O-ring. Fit shaft with pressed-on bearing parts through the bearing
hole on the opposite side. Press in outer bearing ring and tension it inwards with the bearing cover, keeping the
shaft in vertical position and turning it slowly so that the taper rollers of the bearings touch the edge of the outer
bearing ring. Adjust axial bearing clearance with tting discs 0.1mm (20A). Shaft should turn easily with very
little clearance. Tighten inner hexagon screws on con rod (24) to 26 Ft.-Lbs. (35NM).
Important! There should be enough clearance for the con rod to move sideways a little on the journals.
Important! The 1/2” BSP connection in the crankcase serves the purpose of draining leakage water. The
connection should not be closed (see the drawing to the right).
GP5128 Repair Instructions

7
GP5128 Dimensions Inches (mm)
GP5128 Torque Specications/Lubrication Information
Position Item# Description Lubrication Torque Amount
1 13266 Crankcase Molycote Cu-Paste
3 05943 Oil Sight Glass Assembly Loctite 572 22 ft.-lbs. (30 Nm)
10 07008 Inner Hexagon Screw 33 ft.-lbs. (45 Nm)
12 07703 Drain Plug, 3/4” BSP 74 ft.-lbs. (100 Nm)
17 13358 Hexagon Screw 33 ft.-lbs. (45 Nm)
24 13276 Connecting Rod Assy. 22 ft.-lbs. (30 Nm)
31 13284 Radial Shaft Seal Loctite 403
29C 13031 Tension Screw, Plunger Loctite 243 22 ft.-lbs. (30 Nm)
48A 07008 Inner Hexagon Screw, Plug 35 ft.-lbs. (47 Nm)
49 13339 Inner Hexagon Screw, Valve Casing 89 ft.-lbs. (120 Nm)

GIANT INDUSTRIES, INC.,
900 N. Westwood Ave., Toledo, Ohio 43607
Phone [phone], FAX [phone],
www.giantpumps.com
© Copyright 2018 Giant Industries, Inc.
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 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 war-
ranted for ve 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.
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 modications made by the customer or third party.
6. The operation of pumps and or accessories exceeding the specications set
forth in the Operations Manuals provided by Giant Industries, Inc.
Liability under this warranty is on all non-wear parts and limited to the replace-
ment 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 [phone] 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 CON-
SEQUENTIAL 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 WITH-
OUT LIMITATION ANY WARRANTIES OR MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSEANDALLSUCH WARRANTIESARE HEREBYDISCLAIMED
AND EXCLUDED BY THE MANUFACTURER.
07/18 GP5128.indd