Dover PSG NEPTUNE 610 Troubleshooting guide

NEP-ZL105648
06.2019_REV 7
INSTALLATION
OPERATION &
MAINTENANCE
NEPTUNE
Series 600
“dia-PUMPS”
Models
610 THRU 647

WARNING
LOCKOUTS ARE REQUIRED BEFORE
SERVICING THIS EQUIPMENT.
SAFETY INSTRUCTIONS:
Shut off/Lockout pump Power before Servicing.
Be certain pump isolation valves are
Closed and chemical is shut off.
Bleed pressure before servicing.

WARNING
Please read thoroughly before installation, operation or maintenance of any Neptune pump
EQUIPMENT MISUSE HAZARD
Equipment misuse can cause the equipment to rupture, malfunction and result in serious injury.
•
This equipment is for professional use only.
•Read all instruction manuals, tags, and labels before operating the equipment.
•Use the equipment only for its intended use.
•Do not alter or modify this equipment.
•Be certain all operators of this equipment have been trained for safe working practices,
understand it's limitations, and wear safety goggles and or equipments when required.
•Do not exceed the maximum working pressure of the system as mentioned on the pump tag.
•Do not use the pump head or the suction or discharge piping to pull the equipment.
•Do not move pressurized pump.
•Use fluids or cleaning agents for cleaning that are compatible with the pump parts. Read the
fluid and cleaning agent manufactures warnings and also refer to the material compatibility
chart.
•Comply with all applicable local, state and national safety regulation.
•
Do not allow pump to run dry.
PRESSURIZED EQUIPMENT HAZARD
Spray from leaks, ruptured components can splash fluid in the eyes or on the skin and cause serious injury.
•
Shut off the pump and depressurize before performing any maintenance.
•Do not tamper with or perform unspecified alteration of this device .
•Use only pipe, hose, and hose fittings rated for maximum rated pressure of the pump or the
pressure at which the pressure relief valve is set at.
•Always wear protective clothing, face shield, safety glasses and gloves when working on or
near your metering pump.
•Additional precautions should be taken depending on the solution being pumped. Refer to SDS
precautions from your solution supplier.
•Do not stop or deflect fluid leaks with your hand, body, glove, or rag.
•Tighten all fluid connections before operating the equipment.
•Replace worn, damaged, or loose parts immediately.
•Before performing any maintenance requiring pump head and or valve (wetted parts)
disassembly, be sure to relieve pressure from the piping system and where hazardous process
chemicals are present.
•Make the pump safe to handle for the personal and the environment by cleaning and
chemically neutralizing the pump as appropriate.
•Wear protective clothing and use proper tools as appropriate to avoid any injury.
•If the diaphragm has failed, process chemical may have contaminated the pump hydraulic oil.
Handle with appropriate care. Clean the pump and replace oil as necessary. Discard the
contaminated oil as per the local code.
•After the diaphragm failure in a double diaphragm pump, pressurized process chemical can be
present in the Neptune leak detection vacuum system. Take proper care to clean and handle
them.

FIRE AND EXPLOSION HAZARD
Improper grounding, poor air ventilation, open flames, or sparks can cause a hazardous condition and result in
fire or explosion and serious injury.
•
Ground the equipment. See motor installation instruction for grounding procedure.
•Do not pump non recommended flammable or explosive fluids.
•Static electricity may generate by fluid moving through pipes and hoses. A static spark could
be produced by high fluid flow rate. Earthling of the pump is a must.
•Provide fresh air ventilation to avoid the possible build up of flammable fumes from the
process chemicals.
•Keep the pump area free of debris, including cleaning agent, rags, and any flammable material.
•Follow the cleaning agent and other cleaning recommendations as mentioned in the operation
and instruction manuals.
•Use cleaning agent with the highest possible flash point to clean the pump parts if needed.
•If there is any static sparking while using the equipment, stop operation at once. Identify and
correct the problem before starting up the pump.
TOXIC FLUID HAZARD
Hazardous fluids or toxic fumes can cause serious injury or death if splashed in eyes or on the skin,
swallowed, or inhaled.
•
Know the specific hazards of the fluid you are using. Read the fluid manufactures warnings.
•Store hazardous fluid in an approved container. Dispose of hazardous fluid according to all
local, state and national guidelines.
•Wear the appropriate protective clothing, gloves, eyewear and respirator.
•Pipe and dispose of the exhaust air safely. If diaphragm fails, the fluid may be exhausted along
with the air in mechanical diaphragm pump. Also oil vapor may breathe out of the air breather
installed on the gear box.
SOUND HAZARD
The sound pressure level of the pump may exceed 80dBA in some of the pumps.
•
Observe all safety precautions when operating the pump within close proximity for extended
periods by wearing hearing protectors.
•Extended exposure to elevated sound levels will result in permanent loss of hearing acuteness,
tinnitus, tiredness, stress, and other effects such as loss of balance and awareness.
MECHANICAL HAZARD
The pump may shake or vibrate during operation.
•
Vibration could occur due to loose mechanical component and foundation bolts, causing
piping rupture and leakage of chemical to cause bodily injury. The pump should be bolted
down to the base during operation.
•Spills or drips of oil may occur during maintenance of pump, causing the operator to slip or
fall. Clean and neutralize the area as soon as possible with an appropriate cleaning agent.
Always wear protective clothing and gears.
•Pump may overturn when being transported if the motor is too heavy. Secure the pump on its
base before transportation.

TABLE OF CONTENTS
SECTION PARAGRAPH PAGE
I — GENERAL DESCRIPTION 1
LIMITED WARRANTY
2
PARTS ORDERING INSTRUCTIONS 3
II — INSTALLATION INSTRUCTIONS 4
1.0
GENERAL
4
2.0
SUCTION PIPING
5
3.0
DISCHARGE PIPING
6
4.0
ADJUSTMENT OF INTERNAL RELIEF VALVE
6
5.0
INSTALLATION OUTDOORS
8
6.0 START UP PROCEDURE 8
III — NORMAL MAINTENANCE 9-13
7.0 MAINTENANCE 9-13
IV 8.0 MOTOR OPERATING CONDITIONS 14
V — TROUBLE SHOOTING CHART 15-16
VI 9.0 PARTS LIST AND PUMP DRAWINGS 17-26
10.0
SPARE PARTS
27
APPENDIX DOUBLE DIAPHRAGM OPTION 28-29

1
SECTION I
GENERAL DESCRIPTION
The Neptune Series 600 “dia-PUMP” is a reliable metering pump of the high-pressure diaphragm type. Under
constant conditions of temperature, pressure, and capacity adjustment settings, a plus or minus range of 1% metered
discharge volume is maintained.
A plunger reciprocating at a fixed stroke displaces hydraulic fluid, which actuates a flexible, chemically inert, Teflon®
diaphragm to create pumping action. The capacity of the pump is regulated by controlling the volume of hydraulic
fluid, which bypasses the diaphragm cavity.
Metering accuracy is maintained by a control rod, which allows hydraulic fluid replacement and air venting
automatically with each stroke, while also taking into account temperature changes of the hydraulic fluid. Metering
accuracy is also insured by the use of double ball check valves on the suction and discharge of the pump.
PLEASE READ THE INSTRUCTION MANUAL COMPLETELY BEFORE INSTALLING THE PUMP.
SERIES 630 “dia-PUMP”
316SS (N3) HEAD

2
LIMITED WARRANTY
All Neptune Pumps are tested at the factory prior to shipment. Each part used in their construction has been carefully
checked for workmanship.
If the pump is installed properly, Neptune Chemical Pump Company warrants to the purchaser of this product for a
period of thirty six months from the date of first use or eighteen months from shipment, whichever occurs first, this
product shall be free of defects in material and/or workmanship, as follows:
1. Neptune Chemical Pump Company will replace, at no charge, any part that fails due to a defect in material and/or
workmanship during the warranty period, FOB our factory, North Wales, Pennsylvania. To obtain warranty service,
you must get an RMA number to return the defective parts to the factory for examination, freight pre-paid.
2. This warranty period does not cover any product or product part, which has been subject to accident, misuse,
abuse or negligence. Neptune Chemical Pump Company shall only be liable under this warranty if the product is
used in the manner intended by the manufacturer as specified in the written instructions furnished with this
product.
Any express warranty not provided in this warranty document, and any remedy for breach of contract that, but for this
provision, might arise by implication or operation of law, is hereby excluded and disclaimed. Under no circumstances
shall Neptune Chemical Pump Company be liable to purchaser or any other person for any charge for labor, repairs,
or parts, performed or furnished by others, nor for any incidental consequential damages, whether arising out of
breach of warranty, express or implied, a breach of contract or otherwise. Except to the extent prohibited by
applicable law, any implied warranty of merchantability and fitness for a particular purpose are expressly limited in
duration to the duration of this limited warranty.
Some states do not allow the exclusion or limitation of incidental or consequential damages, or allow limitations on
how long any implied warranty lasts, so the above limitations may not apply to you. This warranty gives you specific
legal rights, and you may have other rights, which may vary from state to state.
IMPORTANT
SHOULD IT BE NECESSARY TO SEND THE PUMP TO THE FACTORY FOR REPAIR OR MAINTENANCE
REBUILDING; DRAIN ALL OIL AND CHEMICAL FROM PUMP BEFORE SHIPPING. FAILURE TO DO SO CAN
CAUSE EXTENSIVE DAMAGE TO THE MOTOR.
1SEE IMPORTANT NOTICE -RETURN GOODS AUTHORIZATION
IMPORTANT NOTICE
RETURN GOODS AUTHORIZATION
(1) All equipment returned to Neptune Chemical Pump Company requires proper Returned
Goods Authorization Number (RGA) and tags.
(2) All equipment returned to the factory for repair or service must first be thoroughly flushed
and have all chemical contact areas neutralized.
(3) All equipment which has been in contact with chemicals must be accompanied by a copy
of the chemical product material Safety Data Sheet (SDS).
(4) Failure to comply with the above instructions will result in equipment being returned to
sender, freight collect, without service.

3
PARTS ORDERING INSTRUCTIONS
The complete model number and serial number of the pump must be furnished to insure prompt and
accurate parts service. These numbers are found on the name plate (sample below) located on the side
of the pump. Refer to Section VII for complete parts lists.
Send all orders or inquiries for parts to:
Parts Department
Neptune Chemical Pump Company
295 DeKalb Pike
North Wales, PA 19454
Tel.: [phone]
1 -888-3NEPTUNE (888-363-7886)
FAX: [phone]
Web: www.neptune1.com
Email: [e-mail]
NOTE: PLEASE SUPPLY BOTH MODEL AND SERIAL NUMBERS.

4
SECTION II
INSTALLATION INSTRUCTIONS
1.0 GENERAL
1.0.1 UNPACKING & INSPECTION
When unpacking a pump or chemical feed system, be certain that no parts are thrown away.
Examine the equipment for possible damage. If damage has occurred, file claim with the common
carrier within 24 hours. Neptune will assist in estimating the repair costs.
1.0.2 The "dia-Pump" should be located on a level surface. Four mounting holes are provided to
anchor the pump securely to the mounting surface. All piping to the pump should be supported to
prevent stress on the pump input and output fittings.
1.0.3 Before connecting the pump, make sure that all fittings are completely clean by flushing
thoroughly. Any foreign matter entering the pump can damage the internal parts and severely
limit the life of the pump.
1.0.4 A "Y" STRAINER (AT LEAST ONE PIPE SIZE LARGER THAN SUCTION INLET SIZE OF THE
PUMP) MUST BE INSTALLED IN THE SUCTION LINE OF THE PUMP TO INSURE AGAINST
FOREIGN MATTER ENTERING THE PUMP.
1.0.5 It is recommended that shut-off valves and unions be placed in the suction and discharge lines if
possible. Such an arrangement will facilitate servicing the pump.
1.0.6 The electrical supply to the pump must match the motor nameplate characteristics. The motor
rotation is counter clockwise when viewed from the top of the motor or looking down on the pump.
(See Figure 1)
IMPORTANT
On single phase units, the rotation is set at the factory and must not be changed.
On all units, motor rotation may be viewed through the coupling access points just below the motor.

5
Please note Figure 1, indicating the correct rotation. Operation with the incorrect rotation will
damage the pump and motor.
FIGURE I
1.0.8 Please note, that some items in the parts list have more than one part number for an individual
figure number. These different part numbers insure unique identification of parts which are
available in more than one material 0 construction, or as in the case of gears, more than one
speed. Please use the part number, not the figure number when ordering.
1.0.9 Fill gear box and pump by pouring the hydraulic fluid (drive lubricant) supplied through the fill
opening at the rear of the pump. Pour fluid in slowly until the level is within 2” from the fill hole. The
control knob should be in the zero position during the filling. PLEASE NOTE: TO VENT THE AIR,
REMOVE A VENT PLUG LOCATED ON TOP OF THE OIL HEAD.
Allow 30 minutes for hydraulic fluid to make its way into pump chamber and then recheck fluid
level.
The hydraulic fluid supplied by Neptune is EP SAE 90, Neptune P/N 100225 (1 QT bottle)
Common sources for hydraulic fluid are:
MobilOil
Mobil Gear #629
Sun Oil
Sun Oil #220
Texaco Meropa #220
2.0 SUCTION PIPING
2.0.1 The suction piping to the pump must be absolutely air tight and one size larger than suction inlet
size of the pump. It is suggested that the suction piping be tested with low air pressure and a
soap solution to assure that no leaks exist. Limit the total length of the suction line to 3-4 feet
suction lift or 6-7 feet flooded suction. Minimize bends, elbows, or other restrictions.
2.0.2 NEPTUNE RECOMMENDS THAT THE "dia-PUMP" BE OPERATED WITH A FLOODED
SUCTION, AS THIS WILL FACILITATE START UP AND INCREASE THE SERVICE LIFE OF THE
PUMP.
2.0.3 It is highly recommended that all solution tanks be furnished with a low level cut off switch or low
level alarm and cut off switch to prevent the pump from running dry. OPERATION AGAINST A
DRY SYSTEM WILL CAUSE DAMAGE TO THE PUMP DIAPHRAGM AND REDUCE THE
OPERATING LIFE OF THE PUMP.

6
3.0 DISCHARGE PIPING
3.0.1 It is recommended that the "dia-Pump" operate against a minimum discharge pressure of 50 psig.
3.0.2 All Neptune Series 600 "dia-Pumps" are supplied with an internally pre-set relief valve. This relief valve
is set approximately 25% above the actual rated discharge pressure of the pump
and is designed to protect the pump should a discharge pressure beyond the rated limit of the
pump occur.
3.0.3 To protect the piping system, it is recommended that an external relief valve as manufactured
by Neptune Chemical Pump Company, or equal, be placed in the discharge line of the pump.
3.0.4 Discharge piping should equal discharge port size.
4.0
ADJUSTMENT OF INTERNAL RELIEF VALVE
4.0.1 All Neptune Series 600 "dia-Pumps" are supplied with an internally pre-set relief valve. The
internal relief valve is set as follows:
INTERNAL RELIEF VALVE SETTING (PSI)
Model
1/2 HP
3/4 HIP
1 HIP
1-1/2 HP
2HP
610
1500
2500
3150
4375
-
615
1500
2500
3150
4375
-
620
-
625
750
1000
1500
625
-
625
750
1000
1500
635
-
300
350
550
750
637
-
300
350
550
750
637 PVC
-
250
-
-
-
647
-
-
-
-
300
647 PVC
-
-
-
-
250
The internal relief valve is designed to protect the pump itself should a discharge pressure
beyond the relief valve setting occur.
If a customer order specifies a relief valve setting above those indicated above, the specified
setting will be set at the factory. All pumps are tagged with the relief valve setting used by the
factory.
To protect the external piping system, it is recommended that a relief valve as manufactured by
Neptune Chemical or equal be placed in the discharge line of the pump. It is further
recommended that this relief valve be piped into return of the tank with clear PVC tubing so that
it can be determined if the solution is bypassing through the valve and returning to the tank,
indicating a line blockage.
Drawing on page 18 illustrates the locations of the internal relief valve for Models 610 and 615
(FIG. #1435, #1411, #0145, #0119, #0146, #0120).
Drawing on page 20 illustrates the locations of the internal relief valve for Models 620 and 625
(FIG. #2335, #2311, #0145, #0119, #0146, #0120).
Drawing on page 22 illustrates the locations of the internal relief valve for Models 635 and 637
(FIG. #3235, #3211, #0145, #0119, #0146, #0120).
Drawing on page 24 illustrates the locations of the internal relief valve for Model 647 (FIG.
#3235, #3211, #0145, #0119, #0146, #0120).
The drawing shows a passage connecting the hydraulic fluid reservoir with the hydraulic fluid
side of the diaphragm.
The passage is interrupted by the relief valve ball (FIG. #1435, #2335, #3235) which is backed
up by a relief valve spring (FIG. #0145).
If, during the pump operation, the pressure on the hydraulic fluid side of the pump exceeds the
set pressure of the internal relief valve, the ball is forced from its seat allowing the hydraulic fluid
to flow back to the reservoir.

7
4.0.2 To reset the relief valve to a higher pressure (the relief valve setting cannot be reduced
because of design considerations), instructions are as follows:
4.0.21 Connect a test set-up as shown in Figure IV below. NOTE: All parts must have a
working pressure rating above the required set pressure.
4.0.22 Start and run the pump until all air is relieved from the discharge liquid (hand valve
open).
4.0.23 Remove relief valve cap (FIG. #0120).
4.0.24 Close hand valve; pressure gauge should read between 250 and 4500 psi depending
on pump model.
4.0.25 Use 5/16" Allen wrench to adjust spring tension by turning relief valve adjusting screw
(FIG. #0119).
(1) To increase pressure, turn relief valve adjusting screw (FIG. #0119) in.
(2) To decrease pressure, turn relief valve adjusting screw (FIG. #0119) out.
4.0.26 After resetting or adjusting pressure, replace relief valve cap (FIG. #0120).
CAUTION
Never turn relief valve adjusting screw (FIG. #0119) completely in.
Do not attempt to set the internal relief valve more than 25% in excess of name plate rating.
FIGURE IV

8
5.0 INSTALLATION OUTDOORS
The "dia-Pump" is a totally enclosed pump which can be used outdoors or indoors. When installed out-
doors, make sure that the pump is protected against extremes of nature as follows:
5.0.1 Running of the pump when exposed to tropical sunshine with ambient temperature above 90°F
(32°C) would cause excessive oil and motor temperatures. The pump should be shaded and
located in such a way as to permit an ample degree of air circulation.
5.0.2 Under cold conditions, the pump should be insulated and a heater should be supplied in order
to maintain the hydraulic fluid at an ambient temperature above 30°F (-1°C.)
6.0 START UP PROCEDURE
The following start up procedure is complete and does repeat instructions on filling the gear box
and pump.
6.0.1 Remove back pressure spring (anti-siphon spring) for start up. Reinstall after pump is operational
if needed.
6.0.2 Flooded Suction: Refer to Section II, Paragraph 1.0.9, for instructions on filling gear box with
hydraulic fluid.
6.0.3 After having let pump stand for 30 minutes and having rechecked fluid level, set pump capacity
indicator at approximately 30%. Be certain that pump suction and discharge lines are open.
6.0.4 Make certain that pumping chamber is flooded by loosening vent plug (FIG. #1412 for Models
610 & 615, FIG. #2314 for Models 620 & 625, FIG. #3214 for Models 635 & 637) and allowing
solution to appear. Then tighten discharge vent plug. This procedure will also allow air to vent
from pumping chamber. THE "dia-PUMP" WILL NOT FUNCTION IF AIR IS TRAPPED IN THE
HYDRAULIC FLUID OR LIQUID PUMP CHAMBERS. Start pump.
6.0.5 On initial start ups: Check for proper motor rotation (Refer to Paragraph 1.0.9). Run the pump
for 10-20 seconds, then stop for 20-30 seconds. Repeat approximately 15 times in order to fill
the diaphragm oil cavity. During these short runs, listen for any abnormal motor or crank
noises, and if present, refer to trouble shooting chart.
WARNING
BEWARE APPLICATIONS WHERE WATER IS NOT COMPATIBLE WITH CHEMICAL TO BE
PUMPED. EXAMPLE: NEVER FORCE PRIME WHEN PUMPING ACID OR OIL BASED
PRODUCTS.

9
SECTION III
PUMP MODELS 610 AND 615
NORMAL MAINTENANCE
7.0 MAINTENANCE
Under normal conditions, the "dia-Pump" should not require any significant amount of maintenance. It
is advised that periodic visual observations be made of the oil level; make sure that it is no more than 2" from
the top of oil fill hole. The liquid end of the pump should also be inspected for leakage. These observations
should be made regularly.
The hydraulic fluid should be drained and replaced twice a year, using the drain plug (FIG. #0130) at the back
of the pump. This change can be scheduled with the normal factory maintenance at seasonal periods.
7.0.1 Check Valves: Removing, cleaning, replacing.
The "dia-Pump" incorporates a unique check valve design whereas the discharge and suction piping
NEED NOT be disturbed in order to service the valves.
Should the valves need cleaning, remove as follows:
7.0.11 Remove discharge cap (FIG.#1412).
7.0.12 Remove ball retainer (FIG. #1424) using 5/16" Allen wrench.
7.0.13 Remove discharge valve cartridge (FIG. #1460) using special wrench provided. Be Certain
that valve "0" ring (FIG. #1442) is removed with valve cartridge.
7.0.14 Remove suction cap (FIG. #1428).
7.0.15 Remove suction valve cartridge (FIG. #1462) using 5/16" Allen wrench. Be certain that valve
“0” ring (FIG. #1442) is removed with valve cartridge.
7.0.16 Clean valve cartridges with suitable solvent. The valve cartridge is a complete and integral unit
and should not be disassembled for cleaning if the valves are found to be worn and in need of
replacement; an entire valve cartridge in either suction or discharge should be ordered. The
suction valve is the longer of the two valve cartridges.
7.0.17 To replace, reverse above procedure using a small amount of grease to hold valve "0" rings in
place. Do not over tighten the valve cartridges as this could damage the valve "0" rings.
REFER TO DRAWING ON PAGE 18.

10
SECTION III
PUMP MODELS 620 AND 625
NORMAL MAINTENANCE
7.1 MAINTENANCE
Under normal conditions, the "dia-Pump" should not require any significant amount of maintenance. It
is advised that periodic visual observations be made of the oil level; make sure that it is no more than 2" from
the top of oil fill hole. The liquid end of the pump should also be inspected for leakage. These observations
should be made regularly.
The hydraulic fluid should be drained and replaced twice a year, using the drain plug (FIG. #0130) at the back of
the pump. This change can be scheduled with the normal factory maintenance at seasonal periods.
7.1.1 Check Valves: Removing, cleaning, replacing.
The "dia-Pump" incorporates a unique check valve design whereas the discharge and suction piping NEED NOT
be disturbed in order to service the valves.
Should the valves need cleaning, remove as follows:
7.1.11 Remove vent plug (FIG. #2314) with anti-siphon spring (FIG. #2318) installed.
7.1.12 Remove eight valve cap screws (FIG. #2336) on suction and discharge caps.
7.1.13 Remove discharge cap (FIG. #2312) with retaining screen. Remove suction cap
(FIG. #2328).
7.1.14 With heavy wood dowel or bar of soft material, tap and push complete valve stack out of pump from
top through to bottom. The valve stack consists of:
4 Valve Balls (FIG. #2340)
4 Valve Seats (FIG. #2363)
3 Ball Guides (FIG. #2362)
1 Stack Spacer (FIG. #2361)
4 Valve Seat "0" Rings (FIG. #2342)
NOTE: Valve seats are seated both sides and may be reversed.
7.1.15 Clean valve stack parts with suitable solvent. Replace in same order as removed from top to bottom,
putting suction valve cap (FIG. #2328) in place with "0" ring first.
REFER TO DRAWING ON PAGE 20.

11
SECTION III
PUMP MODELS 635, 637
NORMAL MAINTENANCE
TO VIEW FIGURE NUMBERS:
For Models 635 & 637 refer to Drawing on page 22.
7.2 MAINTENANCE
Under normal conditions, the "dia-Pump" should not require any significant amount of maintenance. It
is advised that periodic visual observations be made of the oil level; make sure that it is no more than 2" from
the top of oil fill hole. The liquid end of the pump should also be inspected for leakage. These observations
should be made regularly.
The hydraulic fluid should be drained and replaced twice a year, using the drain plug (FIG. #0130) at the
back of the pump. This change can be scheduled with the normal factory maintenance at seasonal periods.
7.2.1 Check Valves: Removing, cleaning, replacing.
The "dia-Pump" incorporates a unique check valve design whereas the discharge and suction piping
NEED NOT be disturbed in order to service the valves.
Should the valves need cleaning, remove as follows:
7.2.11 Remove vent plug (FIG. #3214) with anti-siphon spring (FIG. #3218) if installed.
7.2.12 Remove eight valve cap screws (FIG. #3236) on suction and discharge caps.
7.2.13 Remove discharge cap (FIG. #3212) along with retaining screen (FIG. #3216). Remove
suction cap (FIG. #3228).
7.2.14 With heavy wood dowel or bar of soft material, tap and push complete valve stack out of
pump from top through to bottom. The valve stack consists of:
4 Valve Balls (FIG. #3240)
4 Valve Seats (FIG. #3222)
2 Ball Retainers (FIG. #3224)
3 Stack Spacers (FIG. #3226)
1 Valve Ball Spacer Retainer (FIG. #3220)
4 Valve Seat "0" Rings (FIG. #3242)
NOTE: Valve seats are seated both sides and may be reversed.
7.2.15 Clean valve stack parts with suitable solvent. Replace in same order as removed from
top to bottom, putting suction valve cap (FIG. #3228) in place with "0" ring first.

12
SECTION III
PUMP MODEL 647
NORMAL MAINTENANCE
TO VIEW FIGURE NUMBERS:
For Model 647 refer to Drawing on page 24.
7.2.2 MAINTENANCE
Under normal conditions, the "dia-Pump" should not require any significant amount of maintenance. It
is advised that periodic visual observations be made of the oil level; make sure that it is no more than 2" from
the top of oil fill hole. The liquid end of the pump should also be inspected for leakage. These observations
should be made regularly.
The hydraulic fluid should be drained and replaced twice a year, using the drain plug (FIG. #0130) at the
back of the pump. This change can be scheduled with the normal factory maintenance at seasonal periods.
7.2.2.1 Check Valves: Removing, cleaning, replacing.
Should the valves need cleaning, remove as follows:
7.2.2.2 Remove eight valve cap screws (FIG. #3236) on suction and discharge caps.
7.2.2.3 Remove suction and discharge ports (FIG. #3250).
7.2.2.4 With heavy wood dowel or bar of soft material, tap and push complete valve stack out of
pump from top through to bottom. The valve stack consists of:
4 Valve Balls (FIG. #3255)
4 Valve Seats (FIG. #3252)
1 Suction Spacer (FIG. #3256)
3 Stack Spacers (FIG. #3254)
2 Ball Retainers (FIG. #3253)
1 Spacer Retainer (FIG. #3251)
1 Ball Guide Retainer (FIG. #3257)
Replace with new:
4 Valve Seat "0" Rings (FIG. #3242)
2 Suction and Discharge Port "0" Rings (FIG. #3243)
NOTE: Valve seats are seated both sides and may be reversed.
7.2.2.5 Clean valve stack parts with suitable solvent. Replace in same order as removed from
top to bottom, putting suction port (FIG. #3250) in place with "0" Ring (FIG. #3243) first.

13
7.3.1 Procedure for replacing CONTROL ROD "O" RING (FIG. #1434 for Models 610 & 615, FIG.
#2334 for Models 620 & 625, FIG. #3234 for Models 635, 637 & 647) and SEALING PLATE "O"
Ring (FIG. #2333 for Models 620 & 625, FIG. #3233 for Models 635, 637 & 647).
7.3.11 Remove hydraulic fluid from gear box.
7.3.12 Remove indicator plate (FIG. #0118) by removing two indicator plate screws (FIG.
#0143).
7.3.13 Remove control rod assembly with control rod attached (FIG. #0117 for all pumps;
#1406 and #1408 for Models 610 & 615, #2306 and #2308 for Models 620 & 625,
#3206 and #3208 for Models 635, 637 & 647) by turning counter clockwise until
threads are disengaged, then pulling out.
7.3.14 Remove four sealing nut retaining screws (FIG. #0144).
7.3.15 Remove seal plate retainer (FIG. #0166) and sealing nut (FIG. #0115).
7.3.16 Remove seal plate (FIG. #1407 for Models 610 & 615, FIG. #2307 for Models 620 &
625, FIG. #3207 for Models 635, 637 & 647) using small brass hook to pry loose.
7.3.17 Replace control rod "0" ring (FIG. #1434 & 1465 [BACKUP RINGS] for Models 610 &
615, FIG. #2334 for Models 620 & 625, FIG. #3234 for Models 635, 637 & 647) and/or
sealing plate "0" ring (FIG. #1433 for Models 610 & 615, FIG. #2333 for Models 620 &
625, FIG. #3233 for Models 635, 637 & 647).
7.3.18 When replacing sealing plate, take care so as to not shear the sealing plate "0" ring
(FIG. #1433 for Models 610 & 615, FIG. #2333 for Models 620 & 625, FIG. #3233 for
Models 635, 637 & 647). Apply grease to "0" ring before assembly.
7.3.19 Replace balance of parts and fill pump with hydraulic fluid per previous instructions.
7.3.20 Follow start up procedure as if starting a new pump. Refer to Section II, Paragraph
1.0.9 and 6.0.
7.4.1 Removal of pump head and replacement of diaphragm.
7.4.11 Remove drain plug (FIG. #0130), and drain hydraulic fluid.
7.4.12 Remove long and short pump head bolts (FIG. #1438 and #1444 for Models 610 &
615, FIG. #2338 and #2344 for Models 620 & 625, FIG. #3238 and #3244 for Models
635,637 & 647). Lift pump head (FIG. #1402 for Models 610 & 615, FIG. #2302 for
Models 620 & 625, FIG. #3202 for Models 635, 637 & 647) away from pump.
7.4.13 Remove and examine Teflon diaphragm (FIG. #1410 for Models 610 & 615, FIG.
#2310 for Models 620 & 625, FIG. #3210 for Models 635,637 & 647). Remove and
examine the liquid side diaphragm backup plate (FIG. #1430 for Models 610 & 615,
FIG. #2330 for Models 620 & 625, FIG. #3230 for Models 635, 637 & 647). Replace
with new pump, if required. When replacing the Teflon diaphragm, be certain to line it
up properly with the sealing grooves.
7.4.14 To reassemble, reverse the above procedure. Reassembly is facilitated by laying the
pump on its side. Be certain to tighten all bolts evenly.
N3 & N4 (316SS & C-20) PUMPS; Tighten to 100 ft. Ibs.
N5 & N8 (PVC & KYNAR) PUMPS; Tighten to 25 ft. Ibs.

14
SECTION IV
MOTOR OPERATING CONDITIONS
8.0 The normal temperature rise for standard motors is 40°C above ambient temperature and, thus, it might
appear that the motor is operating at a higher than normal temperature. This situation is normal and should
not cause concern.
As a precaution against motor overheating, it is recommended that the pump be located where adequate
ventilation is available. It is also recommended that a MOTOR STARTER WITH THE PROPER
OVERLOAD PROTECTION BE SUPPLIED AS AN ADDITIONAL SAFETY DEVICE.

15
SECTION V
TROUBLESHOOTING CHART
SYMPTOM CAUSE REMEDY
1. Pump Motor Will Not
Operate.
A. Blown Fuse.
Check for short circuit or
overload.
B. Open thermal overload device
in starter.
Reset.
C. Low liquid level in tank (where
low level cut-off is used).
Fill tank.
D. Broken wire.
Locate and repair.
E. Low voltage.
Check for too light wiring.
F. Oil “frozen” in pump.
Thaw out.
2. Pump Does Not Deliver
Rated Capacity
A. Starved suction.
Replace suction piping with
larger size.
B. Leaky suction piping.
Pressure test, repair or replace
defective piping.
C. Excessive suction lift.
Rearrange equipment location
to reduce suction lift.
D. Liquid too close to boiling
point.
Lower temperature or increase
suction pressure slightly.
E. Air or gas trapped in oil or
chemical solution.
Decrease capacity to 20% for
7 mins., then increase to 100%
for 7 mins. Bleed air from valve
system.
F. Worn or dirty valves or seats,
or both.
Clean or replace.
G. Viscosity of liquid too high.
(1) Reduce viscosity by heating
or other means.
(2) Increase size of suction
piping.
(3) Increase suction pressure
slightly.
H. Insoluble materials,
crystallization or solids settling.
Limit solution strength to 5%
By weight. Flush and clean
Solution tank periodically.
Suction connection should
Be 2 to 4” from bottom of
Solution tank.
I. Low discharge pressure.
A minimum discharge pressure
of 50 psi is required to insure
proper capacity control.