Cast White Metal Bearings 1 SCOPE 2 BACKING MATERIAL 3 SURFACE 4 THICKNESS 5 CLEANING PROCEDURE 6 TINNING 7 WHITE METAL 8 BOND SOUNDNESS 9 WITNESSED INSPECTION 10 MACHINING 11 FINAL INSPECTION OF BOND FOR SEAL RINGS APPENDIX A - METHOD OF CALCULATING REFLECTANCE RATIO

1. GBH Enterprises, Ltd.
Engineering Design Guide:
GBHE-EDG-MAC-5710
Cast White Metal Bearings
Information contained in this publication or as otherwise supplied to Users is
believed to be accurate and correct at time of going to press, and is given in
good faith, but it is for the User to satisfy itself of the suitability of the information
for its own particular purpose. GBHE gives no warranty as to the fitness of this
information for any particular purpose and any implied warranty or condition
(statutory or otherwise) is excluded except to the extent that exclusion is
prevented by law. GBHE accepts no liability resulting from reliance on this
information. Freedom under Patent, Copyright and Designs cannot be assumed.
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com

2. Engineering Design Guide:
Cast White Metal Bearings
CONTENTS
SECTION
1
SCOPE
1
2
BACKING MATERIAL
2
3
SURFACE
3
4
THICKNESS
4
5
CLEANING PROCEDURE
5
6
TINNING
6
7
WHITE METAL
7
8
BOND SOUNDNESS
8
9
WITNESSED INSPECTION
9
10
MACHINING
10
11
FINAL INSPECTION OF BOND FOR SEAL RINGS
11
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com

3. APPENDIX A - METHOD OF CALCULATING REFLECTANCE RATIO
DOCUMENTS REFERRED TO IN THIS ENGINEERING DESIGN GUIDE
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com

4. 1
SCOPE
This Engineering Design Guide applies to white metal cast onto steel backings. It
does not apply to thin shell wrapped bearings. It is intended to guide the ordering
of emergency repairs and spares for bearings and seals.
2
BACKING MATERIAL
Steel backings should be in LOW CARBON STEEL to BS 970, 040.A20,
in t he normalized condition.
3
SURFACE
The surface to be white metalized should be fine-turned or ground to a finish of
6.3 µ m Ra. No surface damage is permissible.
4
THICKNESS
The nominal white metal thickness should have been specified by the
makers, but if no data is available then use the following:
( a)
0.5
mm
fixed rings
(b)
floating rings
1
mm
1
2
3
mm
mm
mm
half shells:
< 150 mm dia.
150 - 300 mm dia.
> 300 mm dia.
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com

5. 5
CLEANING PROCEDURE
The steel backings should be cleaned by the following procedure:
(a)
A high pressure paraffin jet.
(b)
Degreasing.
(c)
Alkaline electrolytic bath cleaning.
(d)
Cold water washing.
(e)
Etching in strong (50% per volume) hydrochloric acid. Parts not to be
bonded should be painted with a 15% solution of sodium silicate in
distemper.
6
TINNING
After cleaning, the steel should be immediately dipped in zinc ammonia chloride
flux (surfaces not to be bonded should be protected by painting with a 15%
sodium silicate solution).
The shell should then be coated by dipping into a bath of hot tin (330°C).
A second dipping in tin at 250°C should be done just prior to casting the white
metal.
7
WHITE METAL
Use WM TO BS 3332/2 or BS 3332/8
Wherever possible casting should be carried out by centrifugal
arrangement.
Bore to be machined clean.
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com

6. 8
BOND SOUNDNESS
First, the bore should be machined to obtain a clean surface. An ultrasonic test
should be carried out both from white metal side and from steel side with a 10
mm dual probe to establish the quality of the bond.
Note: A reflection will be seen from the interface. For a perfect bond this
reflection is about 30% of the refraction obtained from metal/air (see Appendix A)
For poor bonds it becomes greater.
The metal interface of the reflection should be calculated with the formula given
in Appendix A. If the reflection ratio is 30% larger than the calculated value the
bond is suspect and the bearing should be rejected.
The bond on seal rings to be 100% on bearings, 90% minimum.
9
WITNESSED INSPECTION
The Inspector should stamp each item after ultrasonic acceptance.
10
MACHINING
Final machine and check dimensions.
11
FINAL INSPECTION OF BOND FOR SEAL RINGS
Carry out a second ultrasonic test - this should show 100% bond for acceptance.
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com

7. DOCUMENTS REFERRED TO IN THIS ENGINEERING DESIGN GUIDE
This Engineering Design Guide makes reference to the following documents:
BRITISH STANDARDS
BS 970
Specification for Wrought Steels for Mechanical and Allied
Engineering Purposes (referred to in Clause 2).
BS 3332
White Metal Bearing Alloy Ingots (referred to in Clause 7 and
Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com