Milton Roy PRIMEROYAL User manual

Primeroyal / Milroyal®Critical
Service HPD Liquid End
Instruction Manual
Manual No : 54261
Rev. : 01
Rev. Date : 05/2019

2Instruction Manual
PRECAUTIONS
The following precautions should be taken when working with metering pumps.
Please read this section carefully prior to installation.
Protective Clothing
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 Safety Data Sheets for the solution being pumped.
Hearing Protection
It is recommended that hearing protection be used if the pump is in an environment where the
time - weighted average sound level (TWA) of 85 decibels is exceeded. (as measured on the
A scale - slow response)
Electrical Safety
• Remove power and ensure that it remains OFF while maintaining pump.
•DO NOT FORGET TO CONNECT THE PUMP TO EARTH / GROUND.
• Electric protection of the motor (Thermal protection or by means of fuses) is to correspond
to the rated current indicated on the motor data plate.
Liquid Compatibility
Verify if the materials of construction of the wetted components of your pump are
recommended for the solution (chemical) to be pumped.
Pumps Water “Primed”
All pumps are tested with water at the factory. If your process solution is not compatible with
water, ush the Pump Head Assembly with an appropriate solution before introducing the
process solution.
Plumbing and Electrical Connections
Always adhere to your local plumbing and electrical codes.
Line Depressurization
To reduce the risk of chemical contact during disassembly or maintenance, the suction and
discharge lines should be depressurized before servicing.
Over Pressure Protection
To ensure safe operation of the system it is recommended that some type of safety /
pressure- relief valve be installed to protect the piping and other system components from
damage due to over-pressure.

3Instruction Manual
Lifting
This manual should be used as a guide only - Follow your company’s recommended lifting
procedures. It is not intended to replace or take precedence over recommendations, policies
and procedures judged as safe due to the local environment than what is contained herein.
Use lifting equipment that is rated for the weight of the equipment to be lifted.

4Instruction Manual
TABLE OF CONTENTS
SECTION 1 - DESCRIPTION................................................................. 5
1.1 SPECIFICATIONS ................................................................ 5
SECTION 2 - INSTALLATION ................................................................ 6
2.1 UNPACKING .................................................................... 6
2.2 SAFETY PRECAUTIONS .......................................................... 6
2.3 MOUNTING ..................................................................... 6
2.4 PIPING CONNECTIONS .......................................................... 6
2.4.1 General....................................................................... 6
2.5 NPSH CONSIDERATIONS ......................................................... 7
2.6 TYPICAL PIPING................................................................. 7
SECTION 3 - OPERATION .................................................................. 8
3.1 PUMP START-UP PROCEDURE (VARIABLE STROKE PUMPS) ........................... 8
3.2 RELIEF VALVE ADJUSTMENT ..................................................... 10
SECTION 4 - MAINTENANCE............................................................... 11
4.1 DIAPHRAGM REPLACEMENT (FIGURE 2, SHEET 1 & 2) ............................... 11
4.2 HYDRAULIC OIL REPLACEMENT .................................................. 12
4.3 MARS REFILL VALVE (400) ....................................................... 12
4.4 RETURNING UNITS TO THE FACTORY ............................................. 12
4.5 RECOMMENDED SPARE PARTS .................................................. 12
4.6 ROUTINE PREVENTIVE MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.7 HYDRAULIC OIL REPLACEMENT .................................................. 13
4.8 CHECK VALVE MAINTENANCE ................................................... 13
4.8.1 Disassembly .................................................................. 13
4.8.2 Re-assembly.................................................................. 13
4.9 CORRECTIVE MAINTENANCE .................................................... 14
4.9.1 Relief Valve Assembly........................................................... 14
SECTION 5 - LEAK DETECTION (PRESSURE SENSING SYSTEM) ................................ 15
5.1 DESCRIPTION. ........... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.2 PRINCIPLE OF OPERATION . .......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.3 SPECIFICATIONS . ........... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
SECTION 6 - INSTALLATION & OPERATION (PRESSURE SENSING SYSTEM) ...................... 16
6.1 UNPACKING ................................................................... 16
6.2 SAFETY PRECAUTIONS ......................................................... 16
6.3 DISASSEMBLY / ASSEMBLY ...................................................... 16
6.4 ELECTRICAL CONNECTIONS .................................................... 17
6.5 NEMA 4 PRESSURE SWITCH WIRING ............................................. 17
6.5.1 Wiring ...................................................................... 17
6.6 EXPLOSION PROOF PRESSURE SWITCH WIRING ................................... 18
6.7 START-UP ..................................................................... 18
SECTION 7 - PARTS ...................................................................... 19

5Instruction Manual
SECTION 1 - DESCRIPTION
Milton Roy’s High Performance Diaphragm
(HPD) liquid end overcomes the Net Positive
Suction Head (NPSH) restrictions associated with
conventional disc diaphragm metering pumps.
This is accomplished by a patented Mechanically
Actuated Rell System (MARS) that eliminates the
process side support plate.
The MARS also does away with the need for eld
adjustment of the rell mechanism by automatically
compensating for process liquid modications.
This, combined with removable check valves,
makes the HPD an ideal choice for any process
in which downtime is critical. The HPD features a
diaphragm that is compatible with a wide range of
process liquids and chemicals.
The HPD liquid end is particularly suitable for
pumping costly, aggressive or hazardous liquids
without leakage.
1.1 SPECIFICATIONS
Steady State
Accuracy / Turndown
Ratio: + 1% over 10:1
Turndown ratio.
Liquid Temperature: +20°F to 250°F
Minimum Suction
Pressure:
3 PSIA minimum
(12 psi maximum vacuum).
Minimum Discharge
Back Pressure:
35 psi above suction
pressure.
Hydraulic Fluid: Mobile SHC-524 or
Equivalent.
Ball Checks: Double ball checks in
suction and discharge.
Gear Lubricant SHC-634 or Equivalent.

6Instruction Manual
SECTION 2 - INSTALLATION
2.1 UNPACKING
Pumps are shipped Free on Board (FOB) from the
factory and the title passes to the customer when
the carrier signs for receipt of it. The customer,
therefore, must le damage claims with the carrier.
The shipping crate should be carefully examined
upon receipt from the carrier to be sure there is no
obvious damage to the contents. Open the crate
carefully, as there are sometimes accessory items
fastened to the inside of the crate that may be lost
or damaged. Examine all material inside crate and
check against the packing list to be sure that all
items are accounted for and undamaged.
2.2 SAFETY PRECAUTIONS
When installing, operating, and maintaining an
HPD pump, keep safety considerations foremost.
Use proper tools, protective clothing, and eye
protection when working on the equipment and
install the equipment with a view toward ensuring
safe operation. Follow the instructions in this
manual and take additional safety measures
appropriate to the liquid being pumped.
Be extremely careful in the presence of hazardous
substances, (e.g. corrosives, toxics, solvents,
acids, caustics, ammables etc.).
2.3 MOUNTING
The HPD liquid end is shipped already mounted
to the appropriate pump. Mounting, therefore, is
simply a matter of securing the pump to a safe,
level surface. For further information on proper
pump mounting, see the appropriate pump
instruction manual.
2.4 PIPING CONNECTIONS
2.4.1 General
General piping instructions are given in the pump
drive instruction manual. No reciprocating plunger
pump can be expected to perform satisfactorily
unless those recommendations are followed.
Pay particular attention to plastic liquid ends,
as these units are relatively fragile and can be
damaged by the installation. For best results, avoid
straining the liquid end by installing a very short
section of exible tubing between rigid, xed piping
and suction and discharge cartridges on plastic
liquid ends.
NOTE:
Maximum safety and reliability may be ensured
by protecting liquid ends and piping with an
external relief valve installed in the system
discharge line.

7Instruction Manual
2.5 NPSH CONSIDERATIONS
The HPD liquid end is far superior to conventional
diaphragm liquid ends for suction lift and many
other NPSH critical applications. It’s patented
diaphragm and advanced design rell mechanism
give this liquid end truly high performance in these
applications.
For more NPSH information, refer to Milton Roy
web site (www.miltonroy.com) for aid in evaluating
applications for this liquid end.
SECTION 2 - INSTALLATION
2.6 TYPICAL PIPING
In order to adjust the HPD relief valve, it is
necessary to have a pressure gauge and a
shut OFF valve installed in the discharge line.
The pressure gauge must have a higher range than
the desired pump relief pressure, and should be
installed as close to the pump discharge connection
as possible. The shut OFF valve should be installed
downstream of the pressure gauge. These items
are not required for normal operation, but for
ease of pump maintenance and adjustment, it is
suggested that they be permanently piped into
the line.
Also see the instructions in the appropriate pump
instruction manual for additional typical piping
instructions.

8Instruction Manual
3.1 PUMP START-UP PROCEDURE
(VARIABLE STROKE PUMPS)
DO NOT RUN THE MOTOR UNTIL
ALL START UP STEPS HAVE
BEEN COMPLETED. YOU COULD DAMAGE THE PUMP IF YOU
RUN THE MOTOR BEFORE ALL OF THE STEPS HAVE BEEN
COMPLETED. IT MAY BE NECESSARY TO TEST THE MOTOR
OFF THE PUMP TO INSURE PROPER DIRECTION AND
OPERATION. THE MOTOR DIRECTION IS CRITICAL. WIRE THE
MOTOR SO THAT IT ROTATES IN THE DIRECTION OF THE
ARROW CAST ON THE MOTOR MOUNT FLANGE. CONSULT
MANUFACTURER DOCUMENTATION FOR MOTOR START UP
RECOMMENDATIONS.
1. Follow the motor mounting procedure before
attempting to start your pumps. On some
pumps, the motor is mounted at the factory.
2. Make the proper electrical connections to the
motor per the manufacturer’s recommendations.
Make sure the motor is properly grounded.
3. Make sure that all of the mounting holes for the
pump base are used to securely tighten the base
to the mounting area.
4. Do not run the motor until ALL start up steps
have been completed.
5. Remove the gear drive ll cap (the chamber
closest to the motor).
6. Fill the gear drive chamber with appropriate
gear lubricant (SHC-634). This oil was shipped
with the pump. Fill this chamber so that the oil
level is even with the midpoint of the sight glass.
Do not overll.
7. Remove the catchall chamber cover (closest to
the process liquid end of the pump) revealing
the plunger and bleed valve. Fill this chamber
with hydraulic oil, ISO -32 (SHC-524). This oil
was shipped with your pump, and is a lower
viscosity compared to the gear oil. The hydraulic
uid must ll the catchall chamber so that the
oil level is even with the midpoint of the sight
glass. Do not overll.
NOTE:
Two types of oils have been provided. They must
be added at the proper location.
8. Remove all of the tubing connecting the air bleed
valve (at the top of the displacement chamber
behind the discharge check valve). There is a
compression tting at the point where the tubing
enters the front catchall reservoir. Loosen the
nut and remove the tubing from this tting.
There is a tting connected to the air bleed
valve that needs to be removed. Remove all air
bleed valves from the top of the displacement
chamber.
9. The displacement chamber must be lled with,
ISO-32 (SHC-524) through the air bleed port.
If pump equipped with leak detection see
Section 5.
IF THE DISPLACEMENT
CHAMBER IS FILLED WITH THE
PLUNGER FULLY REARWARD, THE DIAPHRAGM COULD
RUPTURE AT START-UP. TO PROPERLY FILL THE
DISPLACEMENT CHAMBER, THE PLUNGER MUST BE
POSITIONED SO THAT IT IS TOP DEAD CENTER IN THE
DISPLACEMENT CHAMBER.
10. With the plunger fully engaged in the
displacement chamber (pump at TDC, Top
Dead Center) adjust the stroke adjustment
mechanism until the indicating needle reads
100%. Either turn the hand wheel on a
micrometer, apply a 15-PSI supply signal
for a Pneumatic, or apply a 20-mA signal for
an Electronic actuator. In order to ll each
displacement chamber and fully purge the air
from the oil, rotate the motor either by hand
(by removing the fan cover and spinning the fan
by hand), or by rotating the motor electrically.
The motor may be jogged by turning the power
ON and OFF very quickly. (During this process
watch for air bubbles escaping the oil)
IT IS VERY IMPORTANT NOT TO
ROTATE THE MOTOR AT HIGH
SPEED, BECAUSE HYDRAULIC FLUID WILL BE FORCED FROM
THE AIR BLEED PORT AT A VERY HIGH VELOCITY.
SECTION 3 - OPERATION

9Instruction Manual
SECTION 3 - OPERATION
11. Rotate the motor shaft again so that the pump
is back at TDC (fully extended plunger into the
displacement chamber). Fill this chamber with
ISO-32 oil and check that no air bubbles are
present.
12. Replace the air bleed valve and tighten.
Use a pipe thread sealant to seal the threads.
Be very careful not to get any sealant into the
displacement chamber air bleed port. Place the
end of the tubing into the compression tting
and tighten the lock nut to secure the tubing.
13. On multiplex units, repeat these two steps for
each pump to insure proper hydraulic ll in
each displacement chamber.
14. Recheck the oil level in the catchall reservoir
and install the cover, screws and lock washers.
The gaskets have an adhesive backing that
should be removed and the gaskets should
be rmly attached to the covers using this
adhesive.
15. Make sure that all oil ll caps are securely
tightened to prevent oil leakage.
ALWAYS WEAR THE PROPER
PROTECTIVE GEAR WHEN
WORKING ON THE PUMP LIQUID END.
16. Connect suction and discharge piping
manifolds. Use the proper gaskets and tighten
each ange per specication. Check that all
connections are tight including the check
valves, anges, air bleed valves and the motor
mount bolts.
17. Make sure the process bleeder barb, if so
equipped, is tight. It is located on the front
face of the pump directly under the discharge
check valve. This tting is used to purge any
air that is trapped in the process liquid end.
If this tting is loose when you ll the pump, a
stream of process uid will come out and create
a hazardous condition.
18. It is advisable to test the pump for proper
operation by testing it with water before you
use a process uid. Now ll the process liquid
ends with process uid.
TAKE ADDITIONAL SAFETY
MEASURES APPROPRIATE TO
THE LIQUID BEING PUMPED. BE EXTREMELY CAREFUL IN
THE PRESENCE OF HAZARDOUS SUB-STANCES
(CORROSIVES, TOXINS, SOLVENTS, ACIDS, CAUSTICS, AND
FLAMMABLES).
19. Loosen each process bleeder barb, if so
equipped, on each pump to bleed any air from
the liquid end. Connect a hose to this barb and
use caution if you are pumping a hazardous
chemical. After all process liquid ends have
been purged of air, you can tighten all bleeder
barbs to prevent leakage.
20. Now the motor can be started if and only if all
steps have been followed.
A. For constant speed motors, adjust the stroke
adjustment mechanism so that the indication
needle reads 25-30%. Gradually increase
the capacity adjustment mechanism and
increase back-pressure to insure that the
pump has time to purge all air from the
system.
B. For a variable speed drive, the motor
should be run at a very slow speed between
75-100 revolutions per minute, and the pump
should have minimal process back pressure
for initial start-up. Gradually increase the
motor speed and increase back-pressure
to insure that the pump time to purge all air
from the system.
NOTE:
This concludes the start-up procedure. Please
follow these steps to insure start-up success
and reduce any risk of damage to the pump.

10 Instruction Manual
3.2 RELIEF VALVE ADJUSTMENT
THE PRESSURE RELIEF VALVE
IS FACTORY SET TO OPEN AT A
PRESSURE SLIGHTLY ABOVE THE PUMP MAXIMUM
OPERATING DISCHARGE PRESSURE; NEVER SET THE VALVE
AT ANY GREATER PRESSURE.
All HPD liquid ends have a built in relief valve that
allows hydraulic uid to return to the hydraulic uid
reservoir if excessive pressure builds up in the
discharge line. This effectively stops the pump from
pumping, since the forward stroke of the piston
will not displace the hydraulic uid and force the
diaphragm to ex.
The HPD liquid end relief valve may be adjusted
to operating conditions by the following procedure.
Adjust the relief valve after rst installing the pump
and after any maintenance procedures.
1. A pressure gauge and shut OFF valve must be
installed in the discharge line to complete this
procedure. If the necessary equipment is not
installed, refer to the “Typical Piping” instructions
in Section 2.
2. Make sure shut OFF valve is open. Start pump
and pump process liquid to drain or other safe
point to establish proper pumping action.
3. Set capacity control at 30%.
KEEP HANDS AWAY FROM
RECIPROCATING PLUNGER
AND CROSSHEAD. DO NOT LEAVE PUMP OPERATING
UNATTENDED WITH SHUT OFF VALVE CLOSED. EXCESSIVE
PRESSURE CAN BUILD QUICKLY, POSSIBLY CAUSING
SEVERE DAMAGE TO PUMP AND / OR PIPING. SINCE THE
RELIEF VALVE IS NOT YET PROPERLY ADJUSTED, IT CAN NOT
BE RELIED ON TO LIMIT EXCESSIVE PRESSURE BUILD-UP. BE
SURE TO WATCH PRESSURE GAUGE VERY CAREFULLY AND
OPEN SHUT OFF VALVE IMMEDIATELY IF EXCESSIVE
PRESSURE DEVELOPS.
4. Close shut OFF valve slowly (“dead head” the
pump) and closely watch the pressure increase
on the pressure gauge. If pressure exceeds
desired value, quickly open shut OFF valve to
relieve pressure in line.
5. With shut OFF valve still closed, loosen relief
valve adjusting screw located on top of valve
until the maximum pressure gauge reading
reaches and maintains the relief valve pressure
setting desired.
6. After setting relief valve, make sure shut OFF
valve is fully open. Remove pressure gauge
from line or leave in place, as desired, and place
pump in routine service.
NEVER OPEN THE AIR PURGE
VALVE (IF EQUIPPED 0261)
DURING PRESSURIZED PUMP OPERATION.
7. The diaphragm head is equipped with an
air bleed purge valve built in just below the
discharge port. (Item 0350). The purpose of
this device is to vent entrapped air from the
diaphragm head during priming and start-up.
This end of this tting will accept exible tubing
in order to pipe OFF the solution to a non-
hazardous location. Immediately after priming,
the tting should be tightened.
SECTION 3 - OPERATION

11Instruction Manual
4.1 DIAPHRAGM REPLACEMENT
(FIGURE 2, SHEET 1 & 2)
The HPD diaphragm is extremely durable and often
lasts for many years of service. As a preventive
measure, however, Milton Roy recommends that
the diaphragms be replaced yearly to coincide
with annual check valve replacement. The liquid
end must be removed from the pump to replace
the diaphragm. The following is the diaphragm
replacement procedure:
1. Stop pump and relieve all pressure from system.
Isolate the liquid end from all sources of process
liquid with appropriate valving and purge liquid
end of all process uid.
2. Disconnect both the suction inlet and discharge
outlet from the piping system.
NOTE:
Approximately one pint of oil will still be present
in the contour plate area which will be released
when the diaphragm is removed. Prepare your
work area accordingly.
3. Remove the catchall cover and drain catchall of
hydraulic oil by removing pipe plug at bottom of
casing.
4. Completely loosen the piston rod retention nut
(1750) located inside the catchall.
5. Disconnect all tubing that connects the liquid
end to the pump body.
NOTE:
The liquid end is very heavy (150 lbs. or more).
A hoist is required to move it.
6. Support liquid end with a hoist and unscrew
nuts (980) that hold the displacement chamber
(630) to the pump body. Pull liquid end and
plunger assembly (2000) OFF, being careful
to protect the plunger from damage. Carefully
raise liquid end and plunger over catchall and
pull plunger from liquid end, allowing hydraulic
uid to drain back into catchall. Pull plunger
rmly but carefully, being careful not to bend or
otherwise damage the plunger.
7. Remove relieve valve (1040) and rell valve
(400) from displacement chamber.
8. Place liquid end, diaphragm head up
(bolts (710) on top), on a bench or other clean,
at, and convenient working area.
9. Once the diaphragm head is adequately
supported, the diaphragm head bolts (710)
can be removed. Carefully pull the diaphragm
head (700) away from the displacement
chamber. The diaphragm (670) may pull OFF
with the diaphragm head or remain with the
displacement chamber. Remove diaphragm
(670). (When equipped with leak detection
(See Section 5) remove two diaphragms,
leak detection ring A (8080), leak detection
ring B (8081), and leak detection ring spacer
(8082). Leak detection rings A, leak detection
rings B, and leak detection ring spacer can be
reused).
10. Clean all sealing surfaces and install new
diaphragm (670). (When equipped with
leak detection (See Section 5) install two
diaphragms, leak detection ring A (8080), leak
detection ring B (8081), and leak detection
ring spacer (8082) removed previously.
Apply a small amount of mineral oil between
the diaphragms. Stacked diaphragms and
rings may be aligned using the three small
holes as a guide).
NOTE:
Apply anti-seize thread lubricant to the bolts.
11. Reinstall liquid end on catchall, using the bolts
as a guide.
NOTE:
The bolt torque value stamped on the head only
applies to the material grade supplied with the
pump.
SECTION 4 - MAINTENANCE

12 Instruction Manual
SECTION 4 - MAINTENANCE
12. Torque bolts in sequence to one half of the nal
torque value stamped on the head. Follow the
bolt torque pattern as stamped on the head.
Repeat the torque sequence until bolts are
tightened to nal torque value.
13. Reconnect suction inlet and discharge outlet to
piping system. Follow Section 5 if your pump
is equipped with leak detection.
14. Fill the liquid end with hydraulic oil (refer to
above “INITIAL START-UP” procedure).
4.2 HYDRAULIC OIL REPLACEMENT
Inspect and replace hydraulic oil on same schedule
as the pumps gear drive lubricant (or whenever
diaphragm is replaced). Annual replacement is
recommended.
4.3 MARS REFILL VALVE (400)
The MARS rell valve (400) requires no periodic
maintenance. Clean hydraulic oil is critical for
proper operation.
Strainer service: while replacing the hydraulic
oil, it is also recommended that the hydraulic oil
strainer be replaced. The strainer, (390) which
screws into the displacement chamber can become
fouled or clogged over time.
Screw the valve back into the chamber. If the valve
is damaged or broken, replace the entire assembly.
4.4 RETURNING UNITS TO THE FACTORY
Pumps will not be accepted for repair without a
Return Material Authorization, available from the
factory or other authorized Customer Service
Department. Pumps returned to the factory for
repairs should be clearly labeled to indicate the
liquid being pumped. Process liquid should be
ushed from the pump liquid end before the pump
is shipped.
NOTE:
Federal law prohibits handling of equipment that
is not accompanied by an OSHA Safety Data
Sheet (SDS). A completed SDS must be packed
in the ship-ping crate with any pump returned
to the factory. These safety precautions will aid
the troubleshooting and repair procedure and
preclude serious injury to repair personnel from
hazardous residue in pump liquid end. A Safety
Data Sheet must accompany all returns.
4.5 RECOMMENDED SPARE PARTS
Be Prepared. To avoid delays in repairs, the
following spare parts should be ordered for each
pump:
One Routine Preventive Maintenance Kit, which
contains replacements for those parts which
are subject to wear; specically the ball checks,
check valve seats, gaskets, and the hydraulic uid
strainer. Replacing these parts annually with an
RPM kit can reduce the possibility of unexpected
downtime and will help to extend pump life.
Parts orders must include the following information:
1. Serial number (found on nameplate)
2. Model number (found on nameplate)
3. Quantity required
4. Part number
5. Part description
Always include the serial and model numbers in all
correspondence regarding the unit.

13Instruction Manual
4.6 ROUTINE PREVENTIVE MAINTENANCE
BEFORE ANY MAINTENANCE,
RELIEVE ALL PRESSURE FROM
SYSTEM, ISOLATE LIQUID END FROM ALL SOURCES OF
PROCESS LIQUID WITH APPROPRIATE VALVING, AND PURGE
LIQUID END OF ALL PROCESS LIQUID.
All inquiries on part order should be addressed to
your local Milton Roy sales representative or sent
to: www.miltonroy.com.
4.7 HYDRAULIC OIL REPLACEMENT
Inspect and replace hydraulic oil on the same
schedule as the pump’s gear drive lubricant
(see the appropriate pump drive instruction manual
for this information). Semiannual replacement is
recommended, and can be scheduled to coincide
with season oil changes.
To replace the hydraulic oil:
1. Remove the catchall cover by unscrewing the
four screws, which hold it on.
2. Place a container under the pump catchall to
catch the oil and unscrew the catchall drain
plug.
3. When oil has finished draining, make sure
that the area around the drain hole is clean.
Screw drain plug back in securely.
4. Fill the catchall to the top of the oil seal that
surrounds the crosshead with new, clean oil.
Use hydraulic oil or any good quality type A
automobile transmission uid.
5. Replace the catchall cover the screw rmly in
place.
NOTE:
It is not necessary to purge the liquid end
displacement chamber of oil during annual oil
replacement.
6. Dispose of oil according to federal, state, or local
codes that may apply.
4.8 CHECK VALVE MAINTENANCE
4.8.1 Disassembly
BEFORE PERFORMING ANY
MAINTENANCE ON THE CHECK
VALVES, RELIVE ALL PRESSURE FROM SYSTEM, ISOLATE
LIQUID END FROM ALL SOURCES OF PROCESS LIQUID WITH
APPROPRIATE VALVING, AND PURGE LIQUID END OF ALL
PROCESS FLUID.
After insuring that all system pressure has been
relieved and that all hazardous process liquids
have been ushed from the liquid end, disconnect
both the suction inlet and discharge outlet from the
system piping.
1. Loosen the retaining nut, then remove.
Once disassembled, the O-rings should be
discarded.
2. Check valves may be removed. A compressed
O-ring provides the seal to the head.
Inspect the balls carefully. If they are smooth,
round and free of deposits or pits, then they
are suitable for continued use. Examine the
check valve seats. The area of the seat where
it meets the ball (the un-chamfered side) must
be in near perfect condition for continued use.
Any imperfection visible on the seating surface
(pits, erosion, cracks, or a ball shaped contour
greater than 0.030 deep) makes the seat
unusable. If both the balls and seats are in good
condition, then the length of time between parts
replacement may be lengthened. If the balls and
seats are severely damaged, then the length
of time between parts replacement should be
shortened.
4.8.2 Re-assembly
1. Replace O-ring on the check valves.
Lubricate the O-rings and check valve threads
before assembly.
2. Attach port adapter and tighten retaining nut.
SECTION 4 - MAINTENANCE

14 Instruction Manual
4.9 CORRECTIVE MAINTENANCE
4.9.1 Relief Valve Assembly
The relief valve assembly operates in filtered
hydraulic oil and should require maintenance
only if unusual circumstances occur, such
as if corrosive media contaminates the fluid.
Assembly and disassembly is straightforward.
Field servicing should be limited to inspection and
cleaning only. Repairs of this critical component
should only be carried out by an authorized
Milton Roy repair facility.
SECTION 4 - MAINTENANCE

15Instruction Manual
SECTION 5 - LEAK DETECTION (PRESSURE SENSING SYSTEM)
5.1 DESCRIPTION
(FIGURE 2, SHEET 1 & 2)
Milton Roy’s pumps are, by design, leakproof
and durable. In some applications, however,
added assurance is desired to protect the pump
from hostile chemicals, or protect the process
from contamination by hydraulic uids. For these
situations, Milton Roy has developed a highly
reliable diaphragm rupture detection system.
The diaphragm rupture detection system is an
optional feature, available on the Critical Service
line of metering pumps, which is used to detect
and signal if a hole or tear occurs in one or both
diaphragms. The system consists of two PTFE
diaphragms separated by four leak detection
rings (two A rings (8080) & two B rings (8081)).
Pressure in the four leak detection rings between
the diaphragms is monitored via a pressure
gauge. A machined port in the displacement
chamber at (5021) connects the diaphragms and
rings with tubing, gauge, and or pressure switch.
A low cracking pressure check valve (5000) and
a bleed valve (5100) are located between the
displacement chamber and the pressure gauge.
5.2 PRINCIPLE OF OPERATION
The system consists of two separate diaphragms,
four leak detection rings, leak detection ring
spacer (8082), and a pressure gauge (5030) or
switch (1250). During normal operation, the two
diaphragms are pushed tightly together and are
separated only around their outside edge by the
rings. Because there is no uid and very little air
between the two diaphragms, the system does not
experience pressure from the process when both
diaphragms are intact. The pressure is therefore
at atmospheric pressure, and the pressure gauge
displays 0 psi. The rupture detection system
senses process pressure only when one of the
diaphragms rupture. In the event of a rupture in
either diaphragm, uid rushes into the rings, and
the pressure at the ring rises rapidly to the pump’s
operating pressure. This pressure will be displayed
directly on the pressure gauge for visual indication.
An optional pressure switch is also available to
shut down the pump or provide an alarm signal.
The pressurized uid trapped between the pressure
gauge and the check valve can be relieved via the
bleed valve after the pump is shut down and system
pressure relieved.
5.3 SPECIFICATIONS
Maximum
Pressure Ratings: Same as pump rating.
Materials:
Diaphragms: PTFE
Leak Detection Ring /
Tubing: Steel 304SS or
316SS
Flow Rate: Derate ow by 5% on all
pumps
Accessories:
Pressure Gauge: 316SS
liquid lled (Standard)
Pressure Switch
W/Gauge : NEMA 4 or
Explosion Proof (optional)

16 Instruction Manual
SECTION 6 - INSTALLATION & OPERATION (PRESSURE SENSING SYSTEM)
The Diaphragm Rupture Detection System is
usually shipped already mounted to the pump.
Installation, therefore, is usually only a matter of
piping in the pump, and wiring the pressure switch
if one is provided.
6.1 UNPACKING
Units are shipped Free on Board (FOB) factory
and the title passes to the customer when the
carrier signs for receipt of the unit. In the event
that damages occur during shipment, it is the
responsibility of the customer to notify the
carrier immediately and to le a damage claim.
Carefully examine the shipping crate upon receipt
from the carrier to be sure there is no obvious
damage to the contents. Open the crate carefully so
accessory items fastened to the inside of the crate
will not be damaged or lost. Examine all material
inside crate and check against packing list to be
sure that all items are accounted for and intact.
6.2 SAFETY PRECAUTIONS
When installing, operating, and maintaining a
Critical Service pump with Diaphragm Rupture
Detection, keep safety considerations foremost.
Use proper tools, protective clothing, and eye
protection when working on the equipment
and install the equipment with a view toward
ensuring safe operation. Follow the instructions
in this manual and take additional safety
measures appropriate to the liquid being pumped.
Be extremely careful in the presence of hazardous
substances (e.g., corrosives, toxics, solvents,
acids, caustics, ammables etc.).
6.3 DISASSEMBLY / ASSEMBLY
(REFER TO DRAWING 1029026000,
FIGURE 2, SHEET 1 & 2)
LOOSENING ANY HYDRAULIC
CONNECTIONS OR OPENING
ANY VALVES COULD CAUSE PROCESS LIQUID TO BE
RELEASED UNDER PRESSURE. CAREFULLY DISCONNECT
PUMP FROM ALL ELECTRICAL AND HYDRAULIC SERVICE
BEFORE PERFORMING ANY MAINTENANCE.
1. After shutting down the pump and relieving
system pressure, disconnect all hydraulic
connections.
2. Drain the oil from the catchall.
3. Disassemble the diaphragm head from the
pump body following the instructions in
Section 4.
4. Remove diaphragms (670) and discard along
with four leak detection rings (8080 and
(8081), and leak detection ring spacer (8082).
Items (8080, 8081, and 8082) can be reused
if not damaged by process fluid. Refer to
Figure 2, Sheet 2, Detail C as needed.
IF THE PROCESS FLUID IS
HYDROGEN PEROXIDE OR
ANOTHER STRONG OXIDIZING AGENT, MINERAL OIL SHOULD
NOT BE USED BETWEEN THE DIAPHRAGMS. SUBSTITUTE
WITH A CHLOROTRIFLUOROETHYLENE POLY-MER FLUID
SUCH AS FLOUROLUBE.
5. Clean all sealing surfaces and install new
diaphragms (670), leak detection ring A (8080),
leak detection ring B (8081), and leak detection
ring spacer (8082), leak detection ring A (8080),
leak detection ring B (8081) removed previously
(Figure 2, Sheet 1, Detail C). Apply a small
amount of mineral oil between the diaphragms.
Stacked diaphragms and rings may be aligned
using the three small holes as a guide.
Make sure diaphragms (670) t into pocket on
diaphragm head (700).

17Instruction Manual
6. Reassemble diaphragm head following
Section 4.
7. Once the suction inlet and discharge outlets are
connected to piping system mount the switch
bracket (5090, Figure 2 Sheet 2) then the
remaining components should be tted nger
tight and oriented as shown.
NOTE:
Check the ow direction arrow on the check
valve. The check valve must be assembled with
the arrow pointed toward the pressure gauge
or pressure switch as shown in the gures.
Improper operation will result if the check valve
is not installed correctly.
8. Check all threaded and tube connections to
make sure they are tight.
IMPORTANT
9. Remove the pipe plug(s) and open the bleed-
valve(s). Follow the oil ll and start up procedure
in manual.
10. Leaving the bleed valve(s) open, run the
pump at 100% capacity and normal operating
pressure for 10 minutes. This procedure
purges any excess air and oil from in between
the diaphragms. If too much mineral oil was
placed between the diaphragms in step 5,
some will leak out from the bleed valve(s) at
this point. Lubricant leakage is acceptable.
11. Close the bleed valve(s) and replace the pipe
plug(s). The leak detector assembly is now
complete.
12. Additional oil may need to be purged again.
Return to step 10.
6.4 ELECTRICAL CONNECTIONS
THIS SECTION ONLY APPLIES TO MODELS
EQUIPPED WITH THE PRESSURE SWITCH
ALARM OPTION.
The diaphragm leak detection system can be
equipped with a pressure switch which can be
wired to activate an alarm or shut down the pump
in the event of a diaphragm failure. This switch is
either NEMA 4 (indoor / outdoor, weather and dust
proof) or Explosion Proof (for hazardous locations).
In both cases the switch relay is single-pole double-
throw (SPDT), normally open or normally closed
and rated for 15 amps, 125/240/480 VAC resistive.
6.5 NEMA 4 PRESSURE SWITCH WIRING
The switch terminals are accessed by removing the
two screws retaining the cover and cover gasket.
A 1/2” NPT conduit connection is provided in the
switch enclosure.
6.5.1 Wiring
Unscrew the switch cover to access the wiring
connections. A 3/4” NPT conduit connection
is provided in the switch enclosure. Replacing
the cover hand tight (5 full threads engaged) is
sufcient to maintain proper protection. Additional
tightening may be required to fully engage the
O-ring and seal enclosure for rain tight protection.
SECTION 6 - INSTALLATION & OPERATION (PRESSURE SENSING SYSTEM)

18 Instruction Manual
6.6 EXPLOSION PROOF PRESSURE
SWITCH
ALWAYS WIRE IN ACCORDANCE
WITH LOCAL OR NATIONAL
CODES. BE SURE ALL LIVE SUPPLY CIRCUITS ARE
DISCONNECTED BEFORE WIRING TO THE SWITCH. MAXIMUM
RECOMMENDED WIRE SIZE IS #14 AWG.
The three switch terminals are clearly labeled
“Com” (common), “NO” (normally open), and
“NC” (normally closed). A grounding screw is
also provided. Keep wires as short as possible
to prevent interference with the plunger and
differential switch wheel inside the switch.
IMPORTANT
Connections must always be made through cable
connectors which maintain the integrity of the
NEMA 4 switch or Explosion Proof enclosure.
6.7 START-UP
1. Refer to the manual for pump installation and
start-up instructions.
2. During the initial installation, following any
disassembly of the leak detection system, or if
the pump has not been operated for a prolonged
period, a short break-in procedure for the leak
detector system is required. On duplex pumps,
be sure to follow directions on both sides of the
pump.
a. Open the bleed valve(s) on the leak detection
system.
b. Operate the pump at 100% capacity and
normal system operating pressure. Air and a
small amount of oil may leak from the bleed
valve(s).
c. After a minimum of ten minutes of operation,
close the bleed valve(s).
The break-in operation purges any air and excess
oil which may be trapped in the intermediate ring(s).
The leak detection system is now operational.
Customer Connections
NO
COM
NC
(Violet)
(Blue) (Black)
NO
COM
NC
Internal SPDT Switch Rated
15A, 120/240/480 VAC
Figure 1. Pressure Switch Wiring Diagram
SECTION 6 - INSTALLATION & OPERATION (PRESSURE SENSING SYSTEM)

19Instruction Manual
1. Please refer to the Bill of Material and assembly
for spare parts.
2. Use the drawing to identify the sequence for the
part.
3. The sequence number is used on the drawing
and Bill of Material.
4. Parts should be ordered by the “Part Number”
listed in the Bill of Material.
5. Also reference the sequence number of the part,
since component upgrades occur.
SECTION 7 - PARTS

20 Instruction Manual