Ebsray MD Series Guide

Publication # 1134-09
EBSRAY PUMPS
INSTALLATION, OPERATION & MAINTENANCE
INSTRUCTIONS
MD SERIES
MODELS MD100 – MD212 Std Bracket
INTERNAL GEAR PUMPS
EBSRAY PUMPS PTY.LIMITEDABN 52 000 O61 003
628 PITTWATER RD BROOKVALE NSW 2100
AUSTRALIA
PH: (61 2) 9905 0234 FAX: [phone]

SECTION 1 - GENERAL
INTRODUCTION 1.3 TRANSPORTATION AND PACKING
Standard domestic packing is suitable for shipment in
covered transports. Ports must be sealed to exclude
ingress of solids. When received on site the pump should
be stored in a dry covered area.
This leaflet is intended to assist those involved with the
installation, operation and maintenance of EBSRAY
Models MD100, MD114, MD112 MD200 & MD212 Std
Bracket Internal Gear Positive Displacement Pumps. The
design, materials and workmanship incorporated in the
manufacture of EBSRAY pumps make them capable of
reliable operation over a long working life. Correct
installation is essential. Service life is enhanced by
periodic inspection and careful maintenance.
If storage is required for other than a short period prior to
installation, special preservatives and protective
wrappings will be required. Refer to EBSRAY for details.
1.4 INSPECTION ON RECEIPT - SHORTAGES
On receipt of equipment, check all items against the
dispatch documents and inspect for damage. Any
damage or shortage incurred during transit should be
noted on the packing note and on both your own and the
carrier's copy of the consignment note and a claim
should be made immediately on the transport company.
1.1 CAUTION
INSTALLATION AND SERVICING OF THIS
EQUIPMENT SHOULD BE PERFORMED BY
QUALIFIED COMPETENT PERSONNEL IN
ACCORDANCE WITH RELEVANT STATUTORY
REGULATIONS OR CODES, IN CONJUNCTION WITH
THESE INSTRUCTIONS.
Should a shortage be evident on receipt, notify EBSRAY
immediately giving full details and packing note number.
When the equipment supplied utilises components other
than those manufactured by EBSRAY e.g. couplings,
speed reducers, electric motors etc, reference should be
made to the original manufacturer's data before
installation or servicing is commenced. Failure to observe
these details may void the warranty.
1.5 HANDLING
Do not drop pump/pumpset Care should be taken in
moving/handling pumps/pumpsets. A sling should be
placed under or around a pump/pumpset in order to
minimise stress on the internal components.
The pump/pumpset should be lifted in such a manner as
to ensure compliance with the relevant lifting codes.
1.2
2
The pump must be operated within the original
selected design parameters of speed, temperature,
pressure and viscosity. Should any change be
contemplated, please confer with EBSRAY in order
to verify the suitability of such a change.
Severe internal damage may result if correct
handling and due care is not taken.
SECTION 2 - INSTALLATION
CAUTION
INSTALLATION AND REMOVAL OF THIS EQUIPMENT
SHOULD BE PERFORMED BY QUALIFIED COMPETENT
PERSONNEL IN ACCORDANCE WITH RELEVANT
STANDARDS, CODES, REGULATIONS AND SITE
RESTRICTIONS - IN CONJUNCTION WITH THESE
INSTRUCTIONS.
NEVER LOOSEN OR REMOVE FITTINGS, FLANGES, ETC.
WHILE UNDER PRESSURE, ALWAYS ISOLATE
COMPONENTS OR PIPEWORK AND DEPRESSURISE
PRIOR TO WORK.
2.1 LOCATION
The pumpset should be placed as close as practicable to
the source of supply, keep within the NPSH requirement
of the pump. Ensure floor area and headroom allotted is
sufficient for inspection and maintenance. Allow sufficient
space and ventilation for motor cooling requirements.
Allow for crane or hoist access if required.
2.2 FOUNDATIONS
Baseplate mounted Pumpsets should be accurately
installed. When on a concrete foundation ensure that it
has been poured on a solid footing. NOTE: Position
foundation bolts to match baseplate foundation plan.
Pumpsets must be securely bolted down.
2.3 PUMP PIPING CONNECTIONS
DANGER
WARNING
All piping should be supported independently of and line
up accurately with the pump ports.
SEVERE DAMAGE COULD RESULT IF PIPING IS
DRAWN INTO PLACE BY USE OF FORCE AT THE
PORT CONNECTIONS OF THE PUMP.
2.4 STRAINER PROTECTION
The pump inlet should always be protected by an
efficient strainer of adequate size to accommodate the
liquid viscosity conditions and within NPSHRby the pump

2.5 ALIGNMENT
Alignment of the pump and driver is of extreme
importance for trouble-free mechanical operation.
EBSRAY mounted pumpsets are accurately aligned at
the factory. To ensure this has been maintained during
transit, alignment MUST BE checked once before startup
and again after the pumpset has been run under actual
operating conditions. NOTE: The following procedures
are typical only and reference should be made to data for
specific coupling types.
ANGULAR MISALIGNMENT as shown in Fig.1 should
be corrected before eccentricity. Refer Fig.3; Use feeler
gauge reading at 90o intervals, the amount of correction
necessary can be easily determined to bring shaft axes
in line.
Misalignment due to ECCENTRICITY as shown in Fig 2
can now be corrected. Refer Fig 4, adjustment by use of
shims under the driver or pump will effectively correct
error in the vertical plane. Movement of Pump or Driver
horizontally will correct error in the horizontal plane.
Note: If both coupling halves are of identical diameter
concentricity may be checked with a straight edge at 90o
intervals.
SECTION 3 - OPERATION
3.1 DESCRIPTION
The EBSRAY Internal Gear principle is based upon the
use of an Outer Rotor 'A', idler gear, termed Inner Rotor
'B' and a crescent shaped spacer 'C' which is cast
integral with the Cover. Thus only two moving parts fulfil
this efficient displacement cycle. Power is applied to the
Outer Rotor 'A' and transmitted to the meshing idler or
Inner Rotor 'B'. The rotor teeth cells which are not
involved in the meshing cycle are sealed by the crescent
'C', Body and Cover. (Refer Fig.5)
3.2 PUMPING PRINCIPLE
When rotation is started there is an increase in cell
volume as the teeth come out of mesh. This creates a
partial vacuum and the pressure differential thus created
initiates movement of the liquid through the inlet port 'D',
filling the teeth cells of the two displacement rotors.
When the tooth meshing withdrawal cycle is complete
and the tooth cell volume is filled with liquid, transfer to
the pressure or discharge side is effected as the liquid is
carried past the crescent sealing member 'C'. This
sealing crescent establishes a labyrinth between the high
and low pressure sides, minimising fluid slip. When the
teeth mesh on the pressure side, the liquid is forced from
the teeth cells and flows through the discharge port 'E'.
A noteworthy feature of this simple pump principle is the
absence of high tooth contact pressures when compared
with conventional gear pumps, many of which employ
costly external timing gears to minimise tooth wear. The
Inner Rotor 'B', or idler remains in almost hydraulic
balance requiring only minimal torsional load to
effectively follow the driving Outer Rotor.
Figure 5
3.3 APPLICATIONS
The field of applications for Internal Gear rotary positive
displacement pumps is extensive. These pumps are
used to handle many kinds of liquids over a wide range
of capacities and pressures, associated with viscous or
non-viscous, hot or cold and corrosive or non-corrosive
conditions. Accordingly material, speed and power
specifications vary and it is important to use such
equipment strictly adhering to the manufacturers'
recommendations
3

3.4 LUBRICATION
Lubrication of the Inner Rotor bearing and Bracket
Bearing (both are sleeve bearings) is dependent on the
pumpages' lubricating qualities/material selection of the
bearing.
The Ball Bearing is lubricated at the time of assembly
with a high quality lithium base grease. Replacement of
this grease is normally only necessary when major
maintenance is carried out.
3.5 STARTUP CHECKLIST
•Lubricate as required.
•Alignment of couplings.
•Direction of rotation.
•Freedom of rotation of shaft.
•Inlet and discharge valves open
•Product available for pumping
•Special precautions as required
Note: Do not start pump against closed discharge valve
or with inlet (suction) valve throttled. Ensure bypass
valve (if fitted) is operational and set to the correct
pressure.
Note: Do not exceed system or pump design
pressure as equipment failure could result. Do not
run pump dry. Failure to remove air/vapour could
prevent pump from priming and result in pump
damage.
3.6 OPERATIONAL CHECKS
Inspect pump frequently during the first few hours of
operation for such conditions as excessive heating of
bearings or stuffing box, vibration, unusual noises etc.
3.7 BYPASS VALVE
To protect the pump from overpressure due to
inadvertent shutting of discharge system, EBSRAY can
supply integral or inline Bypass Valves which are capable
of circulating the entire pump output. The integral type
Bypass Valve is mounted on the pump Cover and
bypasses pumpage from the pressure side to the inlet
side of the pump.
The inline type Bypass Valve is installed in the pump
discharge line and normally returns to the inlet side of the
pump or back to tank. Fluid temperature will rise if
differential pressure is high and recirculating bypass
conditions are maintained for extended periods
(particularly with integral Bypass Valve). The Bypass
Valve should be set on site, in accordance with the
predetermined pump and/or system differential pressure
required. Refer separate instructions.
SECTION 4 - MAINTENANCE
CAUTION
PRIOR TO ANY DISASSEMBLY OR SERVICE,
VERIFY THAT ALL REQUIREMENTS OF STATUTORY
REGULATIONS OR CODES ARE MET AND THAT
SPECIFIC SITE REQUIREMENTS ETC ARE
SATISFIED.
Some minor maintenance tasks and inspections can be
performed with the pump 'in line' so long as complete
isolation, depressurising and purging procedures have
been completed. However for major maintenance it is
recommended that the pump be removed from the
installation.
4.1 SPARE PARTS
1. When ordering spare parts, to ensure a minimum
of delay and correct replacement to original
specification ALWAYS quote the pump Serial
Number which is located on the nameplate of the
pump.
2. Advise the Cat #, Description and quantity
required. (Refer to Section 7 – Parts Designation)
3. Advise complete delivery instructions.
4.2 PREPARATION FOR DISASSEMBLY
1. Obtain the appropriate Work Permit if required.
2. Isolate pump from liquids in inlet and discharge
lines, depressurise and purge out any toxic,
flammable, corrosive or air hardening liquids.
3. Isolate power supply to motor.
4. Disconnect porting connections.
5. Remove pump from installation.
6. Mark relevant mating components for correct
reassembly orientation.
4.3 DISASSEMBLY
Note: Before proceeding, make sure Bracket is firmly
attached to baseplate or bench etc. to avoid
overbalancing when rotor is withdrawn. Mark relevant
mating components to ensure correct replacement.
1. Remove pump coupling half, key and Spacer.
2. Release Grubscrew on Outer Lockring and
Grubscrew locking Race Carrier to Bracket
3. If fitted, remove Bypass Valve assembly from
Cover – Refer Section 5.
4. Remove suction/pressure circulation harness
assemblies if fitted.
5. Remove Cover assembly complete with Inner
Rotor. Care should be taken to prevent Inner
Rotor sliding off Inner Rotor Pin. To facilitate
removal of Cover, tapped extraction holes are
fitted
6. Disassemble Cover assembly if required.
.
4

......For pumps fitted with EBSRAY Mechanical Seals:
7. Release Mechanical Seal Plate evenly to avoid
damage.
8. Remove access plug and rotate Shaft until
Drivescrew is accessible, loosen Drivescrew 2 full
turns to clear circlip groove.
9. The Rotor/Shaft assembly can now be driven
through the pump from the drive end taking care to
adequately support the Rotor end.
10. Remove Mechanical Seal components taking care
to avoid damage to lapped faces.
10A. If fitted with carbon bearing remove Extraction
Washer and O-Ring.
.....For pumps fitted with packed glands:
Standard packed glands require correct grade packing
for duty. A Lantern Ring is fitted adjacent to the Rotor
Bearing for suction return and relief of packing pressure.
7. Release Glandplate.
8. The Rotor/Shaft assembly can now be driven
through the pump from the drive end taking care to
adequately support the Rotor end.
9. Remove Glandplate
10. Using a suitable tool, remove Packing and Lantern
Ring.
11. Remove Race Carrier from Bracket.
12. Remove Outer Lockring from Race Carrier.
13. Remove Ball Bearing from Race Carrier.
14. Remove Lip Seals from Outer Lockring and Race
Carrier.
15. Remove Body from Bracket if required.
16. Press out Inner Rotor Bearing and Rotor Bearing if
replacement is required.
4.4 INSPECTION
Inspect components for damage or excessive wear. Note
that typical wear of components in EBSRAY's rotary
Internal Gear positive displacement pumps tend to
compensate each other and working clearances are to
some extent maintained by this compensation. If pump
performance has been satisfactory, existing components
although worn, may still have adequate service life and
could be used provided any burrs or sharp edges are
removed prior to reassembly.
Major refurbishing of the pump should be done in line
with reconditioning to an 'as new' status as replacing or
repairing one component may have an effect on other
components and the working clearances of the pump.
4.5 REASSEMBLY- PRELIMINARY
1. Ensure all parts are clean before assembly.
Remove any burrs.
2. Ensure free running fit of Outer Lockring in Race
Carrier and Race Carrier in Bracket.
3. Fit Lip Seals to Outer Lockring and Race Carrier,
positioning sealing lip towards Bearing.
4. If replacing Rotor Bearing:
a) Metallic: Press-fit, ensuring lubrication groove in
Bearing is in the 12 o'clock position. If the Bracket
has a greaser hole, align lubrication groove with
the greaser hole and drill through after fitting
Bearing.
b) Carbon: The recommended method of fitting
carbon Bearings is shrink-fitting. Press-fitting
carbon Bearings may cause damage to the
Bearing. Fit Bearing flush with spigot face,
ensuring lubrication groove in Bearing is in the 12
o’clock position. Machine or ream to achieve
correct clearance on Shaft ensuring squareness
and concentricity with locating spigot.
5. If replacing Inner Rotor Bearing:
a) Metallic: Press-fit with Bearing flush with one
side of Inner Rotor.
b) Carbon: Shrink fit. (See 4b).
Machine or ream to achieve required clearance on
Inner Rotor Pin ensuring squareness and
concentricity with Inner Rotor O.D.
6. Carry out preliminary sizing checks:
a) Axial length of Inner Rotor, Outer Rotor teeth
and Cover crescent must be matched to within
+/- 0,02mm.
b) Outer Rotor in Body diametral clearance. Note:
If checking by feeler gauge method, allowance
or compensation must be made for eccentricity
caused by:
i) Weight of Rotor.
ii) Clearances between Shaft and Bracket
Bearing.
iii) Lack of Bearing support at drive end
To measure clearance, insert feeler gauge at
two opposite measurement points 'X1'. Add the
two clearances together. This will give the
diametral clearance 'X' for the two points.
Repeat this procedure for the other two
measurement points 'X2'. Refer Figure 7
c) To check clearance between Inner Rotor and
Cover crescent, Inner Rotor should be held
firmly towards crescent. Refer Figure 6
Check clearance ‘V’
between end of tooth and
crescent using a feeler
gauge across the full width
of the tooth.
Figure 6
5

TABLE OF CLEARANCES – Metallic Bearings (All dimensions in millimetres)
Clearance
Grade EBSRAY MODEL Diametral Shaft
to Bearing
W
Diametral
Rotor Pin
to Bearing
Z
Diametral
Outer Rotor
to Body
X
Axial
Rotors
to Cover
Y
Radial
Inner Rotor
to Crescent
V
MD100 0.051/0.089 0.063/0.101 0.10/0.16 0.04/0.07 0.03/0.08
0.03/0.08
MD114 0.051/0.089 0.063/0.101 0.11/0.17 0.04/0.07 0.03/0.08
A MD112
0.051/0.089 0.063/0.101 0.13/0.20 0.05/0.08 0.03/0.08
MD200 0.051/0.089 0.063/0.101 0.15/0.22 0.05/0.08 0.03/0.08
MD212 0.051/0.089 0.076/0.114 0.16/0.25 0.06/0.10 0.03/0.08
MD100 0.076/0.114 0.063/0.101 0.18/0.24 0.08/0.10 0.03/0.08
MD114 0.076/0.114 0.063/0.101 0.19/0.25 0.08/0.10 0.03/0.08
B MD112
0.076/0.114 0.063/0.101 0.21/0.28 0.09/0.12 0.03/0.08
MD200 0.076/0.114 0.063/0.101 0.23/0.30 0.09/0.12 0.03/0.08
MD212 0.076/0.114 0.076/0.114 0.25/0.35 0.12/0.14 0.03/0.08
MD100
0.076/0.114 0.063/0.101 0.27/0.34 0.16/0.19 0.03/0.08
MD114 0.076/0.114 0.063/0.101 0.28/0.35 0.16/0.19 0.03/0.08
C MD112
0.076/0.114 0.063/0.101 0.30/0.38 0.17/0.22 0.03/0.08
MD200 0.076/0.114 0.063/0.101 0.33/0.42 0.17/0.22
MD212 0.076/0.114 0.076/0.114 0.37/0.48 0.20/0.28 0.03/0.08
Figure 7
TABLE OF CLEARANCES – Carbon Bearings (All dimensions in millimetres)
Clearance
Grade EBSRAY MODEL Diametral Shaft
to Bearing
W
Diametral
Rotor Pin
to Bearing
Z
Diametral
Outer Rotor
to Body
X
Axial
Rotors
to Cover
Y
Radial
Inner Rotor
to Crescent
V
0.03/0.08
MD100 0.025/0.063 0.038/0.076 0.10/0.16 0.04/0.07 0.03/0.08
MD114 0.025/0.063 0.038/0.076 0.11/0.17 0.04/0.07 0.03/0.08
A MD112
0.025/0.063 0.038/0.076 0.13/0.20 0.05/0.08 0.03/0.08
MD200 0.025/0.063 0.038/0.076 0.15/0.22 0.05/0.08 0.03/0.08
MD212 0.025/0.063 0.051/0.089 0.16/0.25 0.06/0.10 0.03/0.08
MD100 0.051/0.089 0.038/0.076 0.18/0.24 0.08/0.10 0.03/0.08
MD114 0.051/0.089 0.038/0.076 0.19/0.25 0.08/0.10 0.03/0.08
B MD112
0.051/0.089 0.038/0.076 0.21/0.28 0.09/0.12 0.03/0.08
MD200 0.051/0.089 0.038/0.076 0.23/0.30 0.09/0.12 0.03/0.08
MD212 0.051/0.089 0.051/0.089 0.25/0.35 0.12/0.14 0.03/0.08
MD100
0.051/0.089 0.038/0.076 0.27/0.34 0.16/0.19 0.03/0.08
MD114 0.051/0.089 0.038/0.076 0.28/0.35 0.16/0.19 0.03/0.08
C MD112
0.051/0.089 0.038/0.076 0.30/0.38 0.17/0.22 0.03/0.08
MD200 0.051/0.089 0.038/0.076 0.33/0.42 0.17/0.22 0.03/0.08
MD212 0.051/0.089 0.051/0.089 0.37/0.48 0.20/0.28
6

7
7. Ensure all lubrication/cooling circulation
harness assemblies are clear of any
obstructions.
8. EBSRAY recommends replacement of all
Gaskets, Seals and O-Rings at every overhaul,
to ensure positive sealing.
4.6 REASSEMBLY (Refer Drawing - Section 7)
TORQUE SETTINGS – Std Bracket
Model Body
to Bracket Cover to Body BPV Housing to Cover
MD100 30Nm 13Nm 10Nm
MD114 30Nm 13Nm 10Nm
MD112 30Nm 21Nm 10Nm
MD200 30Nm 21Nm 10Nm
MD212 30Nm 21Nm 13Nm
Note: During reassembly, lubrication is required in
some areas. All lubrication in areas where it may
come into contact with pumped product should be
with a product compatible lubricant. The Bracket Ball
Bearing and Seals may be lubricated with any high
quality lithium base grease suitable for the operating
conditions.
1. Apply a suitable sealant (e.g. Loctite) to the Inner
Rotor Pin bore in the cover. Ensure any excess
sealant is cleaned off exposed faces.Press Inner
Rotor Pin into Cover ensuring lubrication groove
points centrally towards crescent and adequate
support is given around the Inner Rotor Pin bore
boss when pressure is applied.
Note: For jacketed cover, pre-assemble jacket to cover
with new gasket and ensure correct positioning using
bolts in opposite mounting holes and/or studs in bypass
mounting holes.
2. Place Inner Rotor Pin Washer over Inner Rotor Pin
and lock Inner Rotor Pin Nut securely whilst
maintaining lubrication groove location. Note: Use
of a split clamp will aid this operation.
3. Fit Body to Bracket with Gasket between faces.
Maintain correct inlet and discharge port
orientation, securely tighten in a uniform manner.
4. Insert Rotor/Shaft assembly ensuring Rotor Bearing
is lubricated.
5. Fit Inner Rotor over Inner Rotor Pin in Cover
assembly with projecting side (if fitted) towards
Cover; ensure Inner Rotor Pin Bearing is lubricated.
6. Fit Cover assembly to Body with Gasket between
faces, make sure the seal land of the Cover
matches with the seal land in the pump Body. (This
seal land is diametrally opposite the centre of the
Cover crescent). Lubricate pump elements through
pump port and check that Rotor/Shaft assembly
turns freely.
......For pumps fitted with carbon bearings:
6A. Lubricate and Fit O-Ring to Extraction Washer.
Slide Extraction Washer along Shaft until seated
against Rotor Bearing.
......For pumps fitted with EBSRAY mechanical seals:
7A. Slide Circlip along Shaft ensuring gap in Circlip
lines up with access hole. Take care to avoid
scratching Shaft.
7B. Slide Circlip Retainer along Shaft until located
against Circlip (a suitable tube may help keep drive
screw inline with access hole), tighten Drivescrew.
7C. Insert Spring, Drivewasher, Rotating O-Ring,
Rotating Face, Stationary Face fitted with
Stationary O-Ring and lock into position with
Mechanical Seal Plate.
Note: Particular care must be taken to avoid
contamination of lapped seal surfaces by any foreign
matter. All parts should be lubricated before assembly
and Drivepins must be located during assembly.
Mechanical Seal Plate must be fastened evenly.
......For pumps fitted with packed glands:
7A. Place Packing rings in position in accordance with
normal packing procedures, positioning Lantern
Ring in line with access hole. For standard square
Packing with one Lantern Ring, use eight (7) rings
of 9.5mm square Packing. For other types of
packing refer to suppliers instructions.
7B. Position Gland Plate and tighten by hand only.
Final adjustment is carried out during operation of
pump. Packed glands, when adjusted correctly are
designed to have a very small amount of seepage.
If packing is too tight it will generate excessive heat,
if too loose it will leak excessively.
8. Replace lubrication/cooling circulation harness
assemblies if fitted.
9. If fitted, reinstall Bypass Valve – Refer Section 5.
Note: The Bypass Valve Adjusting Screw is oriented
towards the suction port
Note: Use of suitable tools will assist the next steps
10. Lubricate Bracket Ball Bearing. Fit bearing to Race
Carrier and screw Outer Lockring into Race Carrier
until home. Tighten the Grubscrew to lock the Outer
Lockring against the outer ring of the bearing.
11. Lubricate both Lip Seals
12. Screw Race Carrier into Bracket and drive Bearing
into position against shaft shoulder. To assist
movement, bearing should only be tapped on by
using a drift on its inner ring. Do NOT tap on the
face of the Outer Lockring as this could damage the
bearing.
13. Slide Spacer over shaft and through Lip Seal in
Outer Lockring.
14. Fit coupling key and coupling, lock onto Shaft with
Shaft Setscrew and Shaft Washer.

8
4.7 ROTOR AXIAL CLEARANCE ADJUSTMENT
The Race Carrier when finally positioned determines the
Bracket Ball Bearing location within the Bracket. As the
Ball Bearing is positively locked to the Shaft shoulder by
the Spacer sleeve and coupling, the positioning of the
Ball Bearing will control the Rotor axial clearance.
To adjust axial clearance:
a) A crank handle or other suitable arrangement
should be affixed on the coupling end of the
Rotor/Shaft assembly to facilitate rotating of the
assembly by hand.
b) Screw Race Carrier in a clockwise direction
whilst simultaneously rotating assembly. This
enables sensing the rotor-cover point of contact
ie. a slight drag is felt by hand.
c) Mark Race Carrier position relative to Bracket i.e.
establish a datum point for setting axial
clearance.
d) Back off Race Carrier 180 degrees to eliminate
any backlash.
e) Retighten Race Carrier to a point measured
radially from the previously marked datum equal
to the amount of desired axial clearance.
Note: For models MD100, MD114, MD112, MD200 &
MD212 2.99mm radial movement on the O.D. of the
Race Carrier equals 0.025 mm axial movement of the
Rotor/Shaft assembly. Refer Table of Clearances for
actual clearances.
Example: Std 'A' clearance for MD212 – 0.06-0.10 mm
(0.06 ÷0.025) x 2.99 = 7.18
(0.10 ÷0.025) x 2.99 = 11.96
is equivalent to 7-12mm radial movement on the outside
diameter of the Race Carrier.
f) At this point, check for freedom of rotation of
assembly. Axial clearance should now be
established.
g) Tighten Grubscrew locking Race Carrier to
Bracket.
SECTION 5 - INTEGRAL BYPASS VALVES
5.1 GENERAL
This Bypass Valve (BPV) is intended for integral
installation in EBSRAY's Internal Gear Pumps. The valve
is mounted in such a manner as to return liquid from the
discharge side of the pump to the inlet side of the pump
when differential pressure reaches or exceeds a preset
level.
The BPV is mounted with the Adjusting Screw pointing
toward the inlet chamber of the pump.
5.2 OPERATION
The BPV is spring loaded and adjustable within a
pressure range determined by the actual spring used.
EBSRAY can supply a variety of springs to suit varying
differential pressures. They are designed for liquid
service and to provide pump and drive protection from
excessive differential pressures above specified duty
point parameters.
Upon commissioning, the BPV should be adjusted in
accordance with the predetermined pump differential
pressure required.
5.3 MAINTENANCE
Apart from BPV Housing replacement, other
maintenance tasks and inspections can be carried out
with the BPV fixed to the pump Cover, so long as
complete isolation, depressurising and purging have
been completed.
5.4 DISASSEMBLY
1. Remove Adjusting Screw Cap.
2. Unlock Adjusting Screw Locknut. and release
spring tension by unscrewing Adjusting Screw.
3. Unscrew BPV Housing Cap and remove internal
components noting order of assembly.
5.5 INSPECTION
1. Inspect all components for damage or excessive
wear.
2. Repair or replace as required.
5.6 REASSEMBLY (Refer Drawing – Section 7)
Note: Ebsray recommends the replacement of gaskets
during every overhaul.
1. Lap valve into valve seat. . Ensure no lapping
compound remains, as this may damage pump.
2. Screw Locknut onto Adjusting Screw and then
screw Adjusting Screw fully into BPV Cap
3. Fit Valve into Housing, ensuring freedom of
movement.
Note: To maintain assembly stack and reduce spring
tension, back off the Adjusting Screw while tightening the
BPV Cap.
....Poppet type valve as fitted to MD100 & MD114:
3. Fit Spring onto top of Valve.
4. Fit Spring Cap to Spring.
5. Fit Gasket to BPV Housing Cap and screw BPV
Cap onto BPV Housing ensuring that the Adjusting
Screw locates in the hole in the Spring Cap.
....Balanced type as fitted to MD112, MD200 & MD212:
1. Ensure bleed holes in Valve and Pressure Pin are
unobstructed.
2. Assemble Pressure Pin, Spring Retaining Washers
and Spring.
3. Fit Gasket to BPV Housing Cap and screw BPV
Cap onto BPV Housing engaging the Pressure Pin
into Adjusting Screw.

9
5.7 ADJUSTMENT
Note: Final adjustment is carried out after the valve is
mounted on the pump and installed.
1. To avoid overpressuring pump and system always
start on minimum setting i.e. Screw Out
2. For increased bypass pressure, rotate Adjusting
Screw in clockwise direction ( i.e. screw in ). DO
NOT exceed pump or system design pressure.
2. For decreased bypass pressure, rotate Adjusting
Screw anti-clockwise (i.e. screw out).
3. Lock Adjusting Screw Lock Nut against BPV Cap
immediately after any adjustment is made.
4. After Adjustment is completed, fit Adjusting Screw
Cap and Gasket.
Note: Bypass valves characteristically exhibit three
distinct differential pressures during their operation:
a) The set or 'cracking' pressure which occurs
when product initially begins to be bypassed
against the preset spring load.
b) Maximum differential pressure, which occurs
when the flow of the bypassed product passes
through the bypass valve.
c) Full flow differential pressure which occurs
when all the product being pumped passes
through the Bypass Valve.
Note: It is important to ensure the above characteristics
are understood fully in order to correctly apply and adjust
the Bypass Valve in a given system.
SECTION 6 - TROUBLE SHOOTING
6.1 PUMP FAILS TO PRIME OR DELIVER LIQUID
1 No liquid in supply tank.
2 Incorrect direction of rotation.
3 Speed too low:
a) If motor driven, check speed, line voltage and
phases.
b) If engine driven, check governor setting and
engine speed.
4 System discharge head too high - check system
head, friction losses and bypass valve setting.
5 Excessive inlet restrictions - check NPSH available
(inadequately sized inlet piping may cause high
friction losses, vapour pressure of liquid may be too
high). Check with vacuum or compound gauge.
6 Air leaks and/or air pockets in inlet line - check inlet
piping.
7 Bypass valve open due to obstruction under seat of
valve or setting too low.
8 Inlet filter/strainer blocked or leaking air.
9 Pump cannot clear vapour due to excessive
discharge pressure e.g. static head.
6.2 LOW OUTPUT
1 Discharge head too high.
2 Entrained air or gases in liquid pumped.
3 Strainer offering excess resistance to flow.
4 Inlet and/or discharge pipes of insufficient diameter,
causing excessive friction loss.
5 Bypass valve pressure setting too low - Increase
pressure by screwing in adjusting screw. DO NOT
exceed pump or system design pressure, or overload
motor etc.
6 Insufficient NPSH available.
7 Excess axial clearance setting of rotor to cover.
8 Excess clearances in pump due to wear.
6.3 EXCESSIVE POWER CONSUMPTION
1 Differential pressure higher than rating.
2 Liquid properties not as specified - check viscosity.
3 Rotating parts bind - check for proper clearances or
foreign matter in pump.
4 Bearings worn - inspect and replace as required.
5 Obstructions in pipe lines, clogged strainers, partially
open valves.
6 Pump speed too high.
7 Voltage too low.
6.4 PUMP IS NOISY
1 Cavitation is taking place - increase NPSH by:
a) Removing inlet line restrictions created by:
(i) Inadequate pipe sizes / excessive line
lengths.
(ii) Incorrect selection of valves, fittings etc.
(iii) Strainer not permitting free flow of liquid to
pump.
b) Increasing static head in supply vessel.
c) Reduce product viscosity.
2 Rotating parts bind - check for proper clearances.
3 Pump and driver misaligned - check coupling and
realign as required.

SECTION 7 - PARTS DESIGNATION
EBSRAY Pump Models MD100, MD114, MD112, MD200 & MD212 – Std Bracket
CAT# ....................DESCRIPTION........................................................................QUANTITY
1............................Body.........................................................................................1
3............................Cover .......................................................................................1
5............................Cover Gasket...........................................................................1
17..........................Gland Plate..............................................................................1
21..........................Gland Packing .........................................................................To Suit
22..........................Mechanical Seal Rotating Face...............................................1
23..........................Mechanical Seal Stationary Face............................................1
24..........................Mechanical Seal Drive Washer...............................................1
25..........................Mechanical Seal Spring...........................................................1
26..........................Mechanical Seal Drivescrew...................................................1
27..........................Mechanical Seal Plate.............................................................1
29..........................Mechanical Seal Stationary O-Ring........................................1
30..........................Mechanical Seal Rotating O-Ring...........................................1
31..........................Mechanical Seal Circlip...........................................................1
32..........................Mechanical Seal Circlip Retainer ............................................1
36..........................Outer Rotor on Shaft assembly...............................................1
42..........................Shaft Setscrew.........................................................................1
43..........................Shaft Washer...........................................................................1
48..........................Bypass Valve...........................................................................1
49..........................Bypass Valve Body .................................................................1
50..........................Bypass Valve Body Cap..........................................................1
50A .......................Bypass Valve Cap Gasket.......................................................1
51..........................Bypass Valve Spring Cap........................................................1 or 2
52..........................Pressure Pin............................................................................1
53..........................Bypass Valve Spring ...............................................................1
54..........................Bypass Valve Lock Nut............................................................1
55..........................Bypass Valve Adjusting Screw................................................1
56..........................Bypass Valve Adjusting Screw Cap........................................1
56A .......................Gasket - Adjusting Screw Cap................................................1
57..........................Bypass Valve Gasket ..............................................................2
60..........................Inner Rotor...............................................................................1
61..........................Inner Rotor Bearing .................................................................1
62..........................Inner Rotor Pin.........................................................................1
63..........................Inner Rotor Pin Nut..................................................................1
64..........................Inner Rotor Pin Washer...........................................................1
68..........................Bracket.....................................................................................1
69..........................Rotor Bearing...........................................................................1
69A .......................Extraction Washer...................................................................1
69B .......................Extraction Washer O-Ring.......................................................1
70..........................Bracket Gasket........................................................................1
74..........................Bracket Ball Bearing................................................................1
75..........................Race Carrier ............................................................................1
80..........................Bracket Ball Bearing Inner Seal ..............................................1
81..........................Bracket Ball Bearing Outer Lockring.......................................1
82..........................Outer Lockring Grubscrew ......................................................1
83..........................Spacer......................................................................................1
84..........................Bracket Ball Bearing Outer Seal..............................................1
87A .......................Race Carrier Lockscrew..........................................................1
100........................Lantern Ring ............................................................................1
Note: This list covers various pump configurations, before ordering parts, please check the requirements for your
particular pump. Ensure that Pump SERIAL No is quoted when ordering parts.
10

MD1112, MD200 & MD212 Balanced Type
MD100, MD114, MD112, MD200 & MD212 Std Bracket Parts Designation
MD100 & MD114 Poppet Type
11

12
NOTES