Milton Roy MILROYAL G Instruction Manual
MILROYAL® G Pump
Instruction Manual
Manual No : 53942
Rev. : 01
Rev. Date
: 05/2019
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/pressurerelief valve be installed to protect the piping and other system components from damage due
to over- pressure.
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.
i Instruction Manual
TABLE OF CONTENTS
SECTION 1 - DESCRIPTION................................................................. 1
1.1 GENERAL ...................................................................... 1
1.2 PRINCIPLES OF OPERATION ...................................................... 1
1.3 GENERAL SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 PRODUCT CODE ................................................................ 4
SECTION 2 - INSTALLATION ................................................................ 5
2.1 UNPACKING ....................................................................5
2.2 SAFETY PRECAUTIONS .......................................................... 5
2.3 STORAGE ......................................................................5
2.3.1 Temporary Storage .............................................................. 5
2.3.2 Long Term Storage ..............................................................5
2.3.3 Pump Drive.................................................................... 5
2.3.4 Electrical Equipment............................................................. 6
2.4 MOUNTING ..................................................................... 6
2.5 CONVERSION PROCEDURE.......................................................6
2.6 PIPING CONNECTIONS........................................................... 6
2.6.1 NPSH Considerations............................................................ 6
2.6.2 General Piping Considerations..................................................... 7
2.6.3 Suction Piping Considerations .....................................................7
2.6.4 Discharge Piping Considerations ...................................................8
2.6.5 Back Pressure Valves ............................................................8
2.6.6 Pulsation Dampeners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.6.7 Safety Valves .................................................................. 9
2.6.8 Check Valves .................................................................. 9
2.6.9 Shut- OFF Valves ............................................................... 9
2.7 ELECTRICAL CONNECTIONS...................................................... 9
SECTION 3 - OPERATION ................................................................. 10
3.1 INITIAL START-UP............................................................... 10
3.1.1 Start- Up for New Pump ......................................................... 10
3.1.2 Start- Up of Pump Containing No Oil in Casing and Displacement Chamber................. 11
3.2 REFILL VALVE ADJUSTMENT ..................................................... 12
3.2.1 Relief Valve Adjustment (With an Adjustable System Back Pressure Valve). ................. 12
3.2.2 Relief Valve Adjustment (Without an Adjustable System Back Pressure Valve). ............... 13
3.3 USE OF AIR PURGE BUTTON ..................................................... 13
3.4 MANUAL CAPACITY CONTROL .................................................... 14
3.5 FILLING PUMPING SYSTEM ...................................................... 14
3.6 CAPACITY CALIBRATION ......................................................... 14
ii Instruction Manual
SECTION 4 - MAINTENANCE............................................................... 15
4.1 RECOMMENDED SPARE PARTS .................................................. 15
4.2 SHIPPING PUMPS FOR REPAIR .................................................. 15
4.3 ROUTINE PREVENTIVE MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.3.1 Oil Replacement ............................................................... 15
4.3.2 Check Valves ................................................................. 16
4.3.3 Cleaning Fouled Check Valves .................................................... 16
4.3.4 Check Valve Replacement ....................................................... 16
4.3.5 Oil Strainer Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.4 CORRECTIVE MAINTENANCE .................................................... 21
4.4.1 3- Function Hydraulic Valve.......................................................21
4.4.2 “MARS” Valve Assembly ......................................................... 21
4.4.3 Rell Valve Assembly ...........................................................22
4.4.4 Diaphragm Replacement ........................................................22
4.4.5 Removal of Pump Liquid End .....................................................23
SECTION 5 - TROUBLESHOOTING .......................................................... 24
5.1 SYMPTOMS & REMEDIES ........................................................24
SECTION 6 - PART NUMBERS.............................................................. 26
6.1 BASIC PARTS LIST- PUMP DRIVE .................................................. 26
6.2 BASIC PARTS LIST- LIQUID END................................................... 28
6.2.1 Mars Valve ................................................................... 28
6.2.2 Rell Valve ................................................................... 28
6.2.3 3- Function Valve ..............................................................29
6.2.4 Check Valve Parts.............................................................. 29
6.2.5 PVC Liquid End ...............................................................30
6.2.6 Metallic Liquid End .............................................................31
6.3 REMAINING LIQUID END PARTS ..................................................33
LIST OF ILLUSTRATIONS
FIGURE 1. Model/Product Code ............................................................... 4
FIGURE 2. Sample Nameplate............................................................... 34
FIGURE 3. Mounting Hole Dimensions. ........................................................34
FIGURE 4. Typical Recommended Pump Installation Scheme ...................................... 34
FIGURE 5. Pump Drive Parts- Side View ....................................................... 35
FIGURE 6. Pump Drive Parts- Top View........................................................ 36
FIGURE 7. Liquid End- Top View.............................................................. 37
FIGURE 8. Liquid End- Cutaway View ......................................................... 38
FIGURE 9. Mars Value .....................................................................39
FIGURE 10. Double- Ball Check Valve Parts (1-1/4”-plastic;1-3/4, 2-1/2”-PVC & metallic) .................. 40
FIGURE 11. Plastic Single- Ball Check Valve Parts: 1-3/4, 2-1/2, & 3” Plungers.......................... 40
FIGURE 12. Plastic Check Valves for 1-1/4” Plunger .............................................. 41
FIGURE 13. Metallic Check Valves for 1-1/4” Plunger.............................................. 42
FIGURE 14. PVC 4- Function Bleed Valve for 1-1/4” Plunger ........................................ 43
iii Instruction Manual
SECTION 1 - DESCRIPTION
1.1 GENERAL
MILROYAL® G pumps are reciprocating, chemical
dosing pumps capable of producing controlled
ows up to 130 gallons per hour (492 L/H) at
pressures up to 600 psi (41 BAR) (depending on
the model). These pumps feature the robust High
Performance Diaphragm (HPD) liquid end, which
eliminates the need for contour plates, and a
non-lost motion stroke adjustment mechanism
based on the variable eccentric principle. This nonlost motion design substantially reduces pressure
and ow pulsations which in turn increases the
life of system components and results in a more
continuous chemical injection. It is designed
for industrial service and offers an accuracy of
±1% of 100% rated ow between 10% and 100%
of its ow range.
The High Performance Diaphragm (HPD) liquid end
combines all of the best characteristics of traditional
liquid ends into one technologically advanced
design. Its operating characteristics and simplicity
of operation make it the best liquid end to consider
rst for most metering pump applications.
Milton Roy’s HPD liquid end overcomes the
net positive suction head (NPSH) restrictions
associated with conventional disc diaphragm
metering pumps. This is accomplished by a unique
mechanically actuated rell system (MARS) that
eliminates the need for diaphragm support plates
thereby lowering pump NPSH requirements.
The MARS also does away with the need for eld
adjustment of the rell mechanism by automatically
compensating for process liquid modications.
This, combined with removable check valves,
makes the HPD an ideal choice for any process in
which downtime is critical.
The HPD features a preformed, PTFE faced
elastomer diaphragm that is compatible with a
wide range of process liquids and chemicals.
The convoluted design of this composite diaphragm
also offers extended life over conventional at disk
designs.
The HPD liquid end is particularly suitable for
pumping costly, aggressive or hazardous liquids
without leakage.
1.2 PRINCIPLE OF OPERATION
(Refer to Figure 5 Through 10)
The pump consists of two major assemblies;
the drive and the liquid end. Pump delivery is a
function of the drive’s stroke rate (strokes/minute),
plunger size and stroke length (% Capacity).
Stroke length can be adjusted while the pump is
running or stopped by turning the stroke adjustment
knob (330).
The drive motor transmits rotary motion to a
worm gear speed reduction unit (343, 50) which
in turn drives the variable eccentric crank (100).
The adjustable crank imparts reciprocating
motion to the plunger/connecting rod assembly
(60, 520, 525). The stroke length is adjusted by
changing the position of the variable eccentric
crank in the connecting rod assembly.
1Instruction Manual
SECTION 1 - DESCRIPTION
The mechanical drive system of the pump drives
the plunger back and forth in the High Performance
Diaphragm (HPD) liquid end supplied with the
pump. At the start of a suction stroke, the plunger
moves away from the liquid end, drawing hydraulic
uid with it. As the hydraulic uid is drawn back,
the exible diaphragm (510) follows, lowering the
pressure of the process uid in the liquid end.
This pressure drop causes the ball(s) in the suction
check valve (Figure 10) to be lifted up thereby
allowing process uid to pass through the suction
line into the diaphragm head (1020). At the same
time, the pressure drop in the diaphragm head
causes the ball(s) in the discharge check valve
(Figure 10) to be pulled closed, blocking ow back
through the discharge line.
Note:
It is important that the pressure in the liquid
end remain above the vapor pressure of the
process uid during the suction stroke. If the
uid pressure drops below the vapor pressure,
cavitation will occur, negatively impacting the
performance of the pump. If you suspect the
possibility of cavitation, contact your Milton Roy
Representative for assistance.
At the end of the suction stroke, the process
reverses, beginning the discharge stroke.
Now the plunger moves forward, pushing hydraulic
uid before it. The hydraulic oil must therefore press
against the diaphragm, exing it forward and raising
the pressure of the process uid in the liquid end.
This pressure increase causes the process uid
to ow outward, forcing the discharge ball check
open and the suction ball check to seat, blocking
back ow through the suction line. The process
uid ows out of the diaphragm head and into the
discharge line. This suction/discharge action is
repeated with every stroke of the pump plunger,
and is the direct cause of the pumping action.
As the pump operates, a small quantity of hydraulic
oil is continuously bled through the air bleed system
(970, 960, 980 in Figure 8) in the three- function
hydraulic valve (air bleed/relief/purge- Figure 8).
An additional small quantity of hydraulic oil is
also lost on every stroke through the clearance
between the plunger and displacement chamber
bore. After a while, these normal losses result in
a shortage of hydraulic oil in the displacement
chamber. When this happens, the diaphragm will
be pulled back tight against the back contoured
surface of the displacement chamber, and part of
the diaphragm will press against the Mechanically
Actuated Rell System (MARS) valve (Figure 9).
Now, when the plunger draws back, a vacuum is
created in the displacement chamber. These two
factors (diaphragm pressing against MARS valve &
vacuum in the displacement chamber) must occur
together to trigger the MARS valve.
When both of these conditions are met, the MARS
valve is forced to its rearward position, and the
poppet (760) opens, allowing hydraulic oil from
the reservoir to enter through the refill valve
(740 in Figure 8) and replenish the lost oil. In this
manner, proper hydraulic balance is constantly
maintained in the displacement chamber.
2
Instruction Manual
SECTION 1 - DESCRIPTION
1.3 GENERAL SPECIFICATIONS
Maximum Capacity Range 20 GPH (76 LPH) to 130 GPH (492 LPH)
Maximum Pressure Range 100 PSIG (7 Bar) to 600 PSIG (41 BAR)
Liquid End Design
Drive Design Non-Lost Motion Variable Eccentric Type.
Plunger Diameters 1-1/4”(32mm), 1-3/4”(45mm), 2-1/2”(63mm), 3”(75mm)
Liquid End Materials of
Construction
Steady State Accuracy ±1% of 100% rated ow between 10% and 100% of rated ow
Capacity Adjustment
Temperature Limits
Suction Pressure Limits
Lubrication Oil bath drive lubrication.
Paint Two part epoxy, yellow RAL 1018
Hydraulically Actuated Diaphragm with Mechanically Actuated Rell
System (MARS).
PVC, 316 SS, Alloy 20.
Micrometer (Standard): Lockable micrometer is adjustable from
0% to 100% while pump is running or stopped
Electronic (Optional): Electronic stroke length adjustment from
4-20ma input.
Ambient Limit:
Note: Limited by standard lubricants. Modications are available through
Applications Engineering.
Plastic Liquid Ends: 20ºF to 140ºF
Metallic Liquid Ends: 20ºF to 190ºF
Minimum Internal Pressure: 3 psia (11.5 psi maximum vacuum)
Maximum Suction Pressure: 100 psig at 80ºF and below.
130ºF Maximum
0ºF Minimum
Liquid Temperature Limits:
3Instruction Manual
SECTION 1 - DESCRIPTION
1.4 PRODUCT CODE
MILROYAL® G pumps are available in a variety of different congurations. The complete product code
is composed of the pump “model number” + “product code”. For a breakdown of the options included
in a specic pump, compare the pump model number and product code found on the pump nameplate
with the model/product code breakdown shown in Figure 1. A sample nameplate is shown in Figure 2.
MODEL NUMBER
MGH
4 5 6
Digit 4 & 5: Plunger Size Digit 6: Liquid End Material
Description
1-1/4”(32mm)
1-3/4”(45mm)
2-1/2”(63mm)
3”(75mm)
PRODUCT CODE
7 8 9 10 11 12 13 14 15 16 17 18 19 20
Code Description Code
20
28
40
48
316 SS
Plastic (PVC)
Alloy 20
PVDF
1
2
5
7
Digit 7 & 8: Stroking Speed
Description
173 spm 10 No motor, Flange Mount, NEMA 56C CB
120 spm 14 No motor, Flange Mount, NEMA 145TC CC
86 spm 20 No motor, Flange Mount, NEMA 182TC CD
43 spm 30 No motor, Flange Mount, IEC80, F165 Flange MD
*Note: SPM’s for 60 Hz, 1725 rpm motor
Code
Digits 9 & 10: Motor
Description Code
Digits 11 & 12: Capacity Adjustment Connection Digit 13 & 14: Check Valve
Description Code Description Code
Manual, Plastic micrometer knob Electronic(4-20 ma input) M2 Pipe- NPT SE
NEMA 4, 115V E1 Pipe- BSP SN
NEMA 4, 230V E2 Pipe- DN (Socket Weld) SQ
Explosion Proof, 115V EA
Explosion Proof, 230V EB
Electronic 4-20 ma input, 24 VDC EG
Digit 15 & 16: Base Diaphragm Digits 17 & 18: Rupture Detection/Double
Description Code Description Code
No Base (Standard) NN No Rupture Detection, Single Diaphragm (Standard) NN
No Base (Optional) 11 No Rupture Detection, Double Diaphragm (Optional) DD
Rupture Detection (Gauge), Double Diaphragm (Optional) C5
Rupture Detection (Gauge + NEMA 4 Pressure Switch),
DD (Opt.)
Rupture Detection (Gauge + Exp Pr Switch), DD (Optional) SE
Digit 19 & 20: Check Valve Type
Description Code
Single Ball 11
Double Ball 22
Note: Degassing options are available. Consult
MRC factory or representative for details
SN
Figure 1. Model/Product Code
4
Instruction Manual
SECTION 2 - INSTALLATION
2.1 UNPACKING
Pumps are shipped Free on Board (FOB) factory
or representative warehouse and the title passes to
the customer when the carrier signs for receipt of
the pump. 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 the crate and check against packing list to
be sure that all items are accounted for and intact.
2.2 SAFETY PRECAUTIONS
When installing, operating, and maintaining the
MILROYAL® G 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, toxins, solvents,
acids, caustics, ammables etc.).
2.3 STORAGE
2.3.1 Temporary Storage (Less than 6 Months)
It is preferable to store the material under a shelter
in its original package to protect it from adverse
weather conditions. In condensing atmospheres,
follow the long term storage procedure.
2.3.2 Long Term Storage
(Longer than 6 Months)
Primary Considerations
The primary consideration in storage of pump
equipment is to prevent corrosion of external and
internal components. This corrosion is caused
by natural circulation of air as temperature of the
surroundings change from day to night, day to day,
and from season to season. It is not practical to
prevent this circulation which carries water vapor
and other corrosive gasses, so it is necessary to
protect internal and external surfaces from their
effects to the extent possible.
When the instructions given in this section are
completed, the equipment is to be stored sheltered/
protected from direct exposure to weather.
The prepared equipment should be covered with a
plastic sheet or a tarpaulin, but in a manner which
will allow air circulation and prevent capture of
moisture. Equipment should be stored 12” or more
above the ground.
If equipment is to be shipped directly from
Milton Roy into long term storage, contact
Milton Roy to arrange for factory preparation.
2.3.3 Pump Drive
1. Flood the pump drive housing with a high grade
lubricating oil/rust preventative such as Mobile
Oil Corporation product “Mobilarma 524”.
Fill the housing completely to minimize air space
and water vapor condensation. After storage,
drain this material and rell the equipment to the
correct oil level with the recommended lubricant
for equipment commissioning.
2. Remove drive motor and brush all unpainted
metal surfaces with multipurpose grease
(NLGI grade 2 or 3). Store motor unattached.
5Instruction Manual
SECTION 2 - INSTALLATION
2.3.4 Electrical Equipment
1. Motors should be prepared in the manner
prescribed by their manufacturer. If information
is not available, dismount and store motors as
indicated in step 3 below.
2. Dismount electrical equipment (including
motors) from the pump.
3. For all electrical equipment, place packets of
Vapor Phase Corrosion Inhibitor (VPCI) inside of
the enclosure, then place the entire enclosure,
with additional packets, inside a plastic bag.
Seal the bag tightly closed. Contact Milton Roy
Service Department for recommended VPCI
materials.
2.4 MOUNTING
Support the pump rmly in a level position on a
solid, vibration- free foundation, preferably with
the base above oor level to protect the pump
from wash downs and to provide easier access
for service. Be sure to allow enough space around
the pump for easy access during maintenance
operations, pump adjustments, and/or oil lling or
draining procedures.
MILROYAL® G pumps are provided with mounting
holes to accommodate anchor bolts. Refer to
Figure 3 for mounting hole dimensions.
Some MILROYAL® G pumps are shipped with
motors dismounted. After anchoring pump in
position, install motor, referring to Figure 5.
To avoid damage to pump drive during
operation, make sure spring (360) provided with
pump is installed in worm shaft prior to motor
installation. Pumps installed outdoors should be
protected by a shelter.
2.5 CONVENTION PROCEDURE
A MILROYAL® G pump can, in some cases, be
converted from one liquid end plunger size or
material of construction to another. For more
information on converting between different liquid
end models, please contact the Milton Roy factory
or your local authorized representative.
2.6 PIPING CONNECTIONS
2.6.1 NPSH Considerations
The MILROYAL® G HPD liquid end is far superior
to conventional diaphragm liquid ends for suction
lift and many other NPSH- critical applications.
In these demanding applications, the patented
diaphragm and rell mechanism give this liquid
end truly exceptional performance.
For NPSH apply a 3 psia limitation (instead of
9 psia) in evaluating applications for this liquid end.
Size piping to accommodate peak instantaneous
flow. Because of the reciprocating motion of
the pump diaphragm, pump delivery follows an
approximate sine curve with a peak instantaneous
ow equal to pi (3.14) times the average ow.
Therefore, piping must be designed for a ow
3.14 times the pump capacity; this means that a
pump rated for 100 gallons per hour (379 L/hr.)
requires piping sufcient for 3.14 x 100 gph, or
314 gph (1188 L/hr.).
To minimize viscous ow losses when handling
viscous liquids, it may be necessary to use suction
piping up to four times larger than the size of
the suction connection on the pump. If in doubt,
contact your nearest Milton Roy representative to
determine the necessary pipe size.
6
Instruction Manual
SECTION 2 - INSTALLATION
2.6.2 General Piping Considerations
1. Use extreme care in piping to plastic liquid
end pumps with rigid pipe such as PVC. If any
stresses or vibration are unavoidable, exible
connections are recommended.
2. Use piping materials that will resist corrosion by
the liquid being pumped. Use care in selecting
materials to avoid galvanic corrosion at pump
liquid end connections.
3. Use piping heavy enough to withstand maximum
pressures.
4. Remove burrs, sharp edges, and debris from
inside piping. Blow out all pipelines before
making nal connections to pump.
5. Because vapor in the liquid end will cause
inaccurate pump delivery, piping should be
sloped down to pump suction check valve to
prevent vapor pockets.
6. When pumping suspended solids (such as
slurries), install plugged crosses at all 90° line
turns to permit line cleaning without dismantling
piping.
7. See Figure 4 for a typical recommended pump
installation scheme.
2.6.3 Suction Piping Considerations
1. It is preferable to have the suction of the pump
ooded by locating the liquid end below the
lowest level of the liquid in the supply tank.
Installing the supply vessel on the suction line
in close proximity to the pump will help ensure
a ooded suction line.
2. Avoid negative suction pressure conditions
(suction lift), as such conditions adversely
affect metering accuracy. A lift of 20 Ft. of water
column straight out of a supply tank is the
maximum suction lift permissible.
3. MILROYAL® G pumps are intended to be
operated with process liquid supplied at or
above atmospheric pressure. Although these
pumps can move liquids supplied at less
than atmospheric pressure, in these negative
pressure applications it is important that all
connections be absolutely drip free and vacuum
tight.
4. When pumping a liquid near its boiling point,
provide enough suction head to prevent the
liquid from “ashing” into vapor when it enters
the pump liquid end on the suction stroke.
5. If possible use metal or plastic tubing for the
suction line because such tubing has a smooth
inner surface and can be formed into long,
sweeping bends to minimize frictional flow
losses.
6. A strainer should be used in the suction line to
prevent foreign particles from entering the liquid
end. This and any other measures to prevent
debris from entering and fouling the ball-checks
will give increased maintenance-free service.
Check strainer frequently to prevent blockage
which could lead to cavitation.
7. Keep suction piping as short and straight as
possible.
8. Piping size should be one or two sizes larger
than the liquid end suction tting to prevent
pump starvation.
9. If long suction lines are unavoidable, install a
stand pipe or suction accumulator dampener
near the pump in the suction line.
10. Suction piping must be absolutely airtight to
ensure accurate pumping. After installation,
test suction piping for leaks with air and soap
solution.
7Instruction Manual
SECTION 2 - INSTALLATION
2.6.4 Discharge Piping Considerations
1. Install pipe large enough to prevent excessive
pressure losses on the discharge stroke of the
pump. Maximum pressure at the discharge
tting on the liquid end must be kept at or below
the rated pressure (Max. allowable working
pressure shown on the pump nameplate).
2. The pump will not deliver a controlled ow unless
the discharge line pressure is 35 psi greater than
the suction line pressure. There are a number of
ways to create an articial pressure, such as by
installing a back pressure valve. (Please contact
Milton Roy for recommendations to increase
back pressure in slurry applications.)
3. When pumping water-treatment chemicals
directly into boiler drums, use one liquid
end assembly for each boiler drum.
Discharging into a manifold having the slightest
pressure difference between its several
discharge connections can diminish metering
accuracy as the outlet with the lowest pressure
will receive more liquid than the outer outlets.
2.6.6 Pulsation Dampeners
An accumulator, surge chamber, surge suppressor,
or pulsation dampener should be used with the
back pressure valve in the discharge line to
absorb the ow peaks between the pump and
the back pressure valve. Without the pulsation
dampener the valve mechanism will snap open
and closed with the surge from each pump stroke.
The pulsation dampener will allow the back
pressure valve to oscillate about a partly-closed
position, thus minimizing wear on the valve.
Discharge line pulsation dampeners offer the
further advantage of limiting the ow and pressure
variations characteristic of this kind of pump.
Installing a properly sized pulsation dampener
will improve pump performance and may reduce
system costs dramatically by permitting the
substitution of smaller piping. Please contact
Milton Roy for further information on pulsation
dampeners.
2.6.5 Back Pressure Valves
A Milton Roy Back Pressure Valve should be
installed in the discharge line near the pump to
ensure sufficient discharge head pressure for
proper pump metering action. Normally, the valve
should be located near the pump. However, back
pressure valves for large pumps with long and
extremely small discharge lines may have to
be installed near the point of discharge into the
process (to minimize siphoning tendencies).
8
Instruction Manual
SECTION 2 - INSTALLATION
2.6.7 Pressure Relief Valve (PRV)
Maximum safety and reliability may be ensured by
protecting liquid ends and piping with an external
pressure relief valve installed in the system
discharge line. Although the pump is protected
against excessive pressure by an internal relief
valve, to prevent a blocked discharge line from
causing damage to the piping or process equipment,
install a Milton Roy pressure relief valve in the pump
discharge line. This valve is designed and sized to
handle system ow rates and pressures safely
while resisting corrosion by the process liquid.
Install the safety valve in the discharge line
between the pump and the nearest shut- OFF
valve. (This will prevent potential system damage
from accidental valve closure.) Pipe the pressure
relief valve outlet back to the suction tank or to
drain, but in either case ensure that the pipe end
is continuously visible so pressure relief valve
leakage may be detected. Milton Roy pressure
relief valve must be installed in accordance with its
user manual top of supply tank in order to function
properly.
2.6.8 Check Valves
A check valve should be installed at the point
where the discharge line enters a boiler or other
high-pressure vessel. This will prevent back ow
through the discharge piping and will isolate the
pump discharge from system pressures (a safety
consideration).
2.6.9 Shut- OFF Valves
In order to isolate the pump during maintenance,
provide shut- OFF valves in both suction and
discharge lines next to the pump. Locate discharge
line shut- OFF valve downstream from the inlet
connection of the safety valve. Figure 4 shows
recommended valve locations.
2.7 ELECTRICAL CONNECTIONS
Ensure that the electrical supply matches the pump
motor nameplate characteristics. Before operating
the pump, check the direction of rotation of the
motor to be sure it matches the direction of the
arrow stamped on the motor (rotation should be
clockwise when viewed from the top of the motor).
If motor rotation is incorrect, refer to the motor
data plate or motor manufacturer’s instructions
for reversing.
OPERATION WITH THE WRONG
MOTOR ROTATION WILL DAMAGE
THE PUMP AND MOTOR AND VOID THE WARRANTY.
DO NOT FORGET TO CONNECT
THE PUMP TO AN EARTH
GROUND!
Electric protection of the motor (fuses, overload
meters or relays) should correspond to the rated
current indicated on the motor data plate.
9Instruction Manual
SECTION 3 - OPERATION
3.1 INITIAL START- UP
Check that all mounting bolts are tight, piping is
installed properly, and the discharge line is open.
Check oil drain plug for tightness. Remove the
orange oil ll cap and ll the pump casing until
level is between the top two marks on the oil cap
dipstick. (approximately 3-1/2 quarts). DO NOT
OVERFILL ABOVE TOP DASH!
Note:
The oil furnished with the pump is grade AGMA
No. 5 EP with a viscosity of 1000 SSU at 100°F
(218.4 cSt at 40°C). For operation in ambient
temperatures below 50°F (10°C), substitute
AGMA No. 2 EP with a viscosity of 400 SSU
at 100°F (86.4 cSt at 40°C). Manufacturers’
equivalent oils are shown below.
DO NOT START UP PUMP DRIVE
MOTOR BEFORE FILLING GEAR
BOX WITH OIL OR SERIOUS DAMAGE WILL OCCUR.
Chevron N.L. Gear Compound
220
ABOVE 50°F:
BELOW 50°F:
Food Grade
Alteration
Exxon Spartan E.P. 220
Mobil Mobilgear 630
Texaco Meropa 220
Chevron N.L. Gear Compound 68
Exxon Spartan E.P. 68
Mobil Mobilgear 626
Texaco Meropa 68
Shell Omaha 68
Nevastane EP220
3.1.1 Start- Up for New Pump
For pumps received from the factory, the
displacement chamber (600) is already lled with
oil. Simply remove the orange oil ll cap from the
pump casing and ll the casing with the specied
oil to a level between the top two dashes on the
dipstick. DO NOT OVERFILL ABOVE TOP DASH!
Pump is now ready for operation. Operation of
the air purge button may be required to remove
air that may have come out of solution from the
oil during shipment and storage. Refer to “USE
OF AIR PURGE BUTTON” section for operation
instructions. The integral pump relief valve is
factory adjusted according to customer specied
setting. For instructions on adjustment of the pump
relief valve please refer to the next section.
BEFORE SWITCHING ON POWER
TO THE PUMP, TURN THE
CAPACITY ADJUSTMENT KNOB TO ZERO. CHECK THAT ALL
SHUT- OFF VALVES IN THE SUCTION AND DISCHARGE LINES
ARE OPEN BEFORE INCREASING THE CAPACITY
ADJUSTMENT FROM ZERO.
10
Instruction Manual
SECTION 3 - OPERATION
3.1.2 Start- Up of Pump Containing No Oil
in Casing and Displacement Chamber
The following instructions assume that both the
pump casing and liquid end (displacement chamber)
contain no oil. This condition typically exists when
the pump is subjected to annual maintenance
during which oil may be drained from the pump
casing and oil may escape from the displacement
chamber during diaphragm replacement.
New pumps received from the factory will have
an empty pump casing and a lled displacement
chamber (liquid end). Please refer to the previous
section for start- up of new pumps. After pump
casing is lled to correct oil level (between top two
dashes on oil cap dipstick), perform the following
operations before placing the pump into service.
Numbers refer to item numbers shown in assembly
drawings (Figures 7-9) located in the back of this
manual.
1. Remove hydraulic 3- function valve (refer to
Figure 8):
a. Remove relief valve cap piece (850).
b. Make sure relief valve locknut (900) is tight
to maintain previous relief valve setting upon
start- up.
c. Remove purge button and relief valve
adjustment assembly by removing large
adjustment nut (910).
d. Using needle-nose pliers, remove spring
(950).
e. Using same pliers, remove relief valve poppet
by gently gripping the top of the valve body
(960).
2. Make sure pump capacity adjustment is set to
100%.
3. Fill the opening in the displacement chamber
(600) through the port uncovered by removal
of the 3- function valve in step 1 with the same
oil used to ll the pump casing. Fill the chamber
slowly, allowing air bubbles to escape, until
the oil level reaches the level of the drain tube
(640).
4. Reinstall 3- function valve:
a. Gently gripping the top of the relief valve
poppet (960) with needle-nose pliers, drop
the poppet assembly down into the empty
relief valve port.
b. Drop spring (950) back into relief valve port.
c. Make sure washer (935) is in place above
the O-ring (940) on purge stem (930) and
reinstall purge and relief valve adjustment
assembly by screwing large adjustment nut
(910) back into place. Make sure adjustment
nut (910) is tight.
d. Reinstall relief valve cap piece (850).
5. The pump is now properly lled with oil and ready
for service. If the relief valve locking nut (900)
remained tight during the above procedure, the
relief valve setting should remain unchanged.
If not, refer to next section for instructions on
how to set relief valve.
BEFORE SWITCHING ON POWER
TO THE PUMP, TURN THE CAPACITY
ADJUSTMENT KNOB TO ZERO. CHECK THAT ALL SHUT- OFF VALVES
IN THE SUCTION AND DISCHARGE LINES ARE OPEN BEFORE
INCREASING THE CAPACITY ADJUSTMENT FROM ZERO.
6. Make sure that all air has been bled from the
suction piping and pump head. This can be
accomplished by opening all suction line valves
as well as the system drain (Prime/Air Purge)
valve shown in Figure 4 and allowing uid to ow
into drain until all air has been purged. If drain
valve not present, with the pump capacity set
to 100%, operate the pump under no discharge
pressure until the entire pumping system has
been lled.
11Instruction Manual
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