DNVGL-CP-0081 Synthetic bearing bushing materials

The electronic pdf version of this document, available free of chargefrom http://www.dnvgl.com, is the officially binding version.

DNV GL AS

CLASS PROGRAMME

Type approval

DNVGL-CP-0081 Edition February 2016

Synthetic bearing bushing materials

FOREWORD

DNV GL class programmes contain procedural and technical requirements including acceptancecriteria for obtaining and retaining certificates for objects and organisations related toclassification.

© DNV GL AS February 2016

Any comments may be sent by e-mail to [email protected]

This service document has been prepared based on available knowledge, technology and/or information at the time of issuance of thisdocument. The use of this document by others than DNV GL is at the user's sole risk. DNV GL does not accept any liability or responsibilityfor loss or damages resulting from any use of this document.

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Class programme — DNVGL-CP-0081. Edition February 2016 Page 3Synthetic bearing bushing materials

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CONTENTS

Changes - current...................................................................................................3

Section 1 General....................................................................................................51 Introduction.........................................................................................52 References........................................................................................... 73 Documentation.....................................................................................8

Section 2 General requirements............................................................................101 Design requirements..........................................................................102 Requirements for production and quality control arrangement..........103 Requirements for material.................................................................104 Wear testing procedure for synthetic rudder bearing bushingmaterials...............................................................................................155 Approval for use in non-lubrication (dry-running) applications..........166 Approval of synthetic propeller shaft bearing materials.................... 167 Wear testing procedure for synthetic propeller shaft bearingmaterials...............................................................................................178 Requirements for marking of product................................................18

Appendix A General scheme for type testing........................................................ 191 All surface pressures – entry of type test results.............................. 192 All surface pressures – up to 5.5 N/mm2 - entry of type testresults...................................................................................................203 All surface pressures – above 5.5 N/mm2 and up to max. 10 N/mm2 - entry of type test results...........................................................22

Changes – historic................................................................................................24

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SECTION 1 GENERAL

1 Introduction

1.1 ObjectiveThe objective of this class programme (CP) is to give a description of the type approval (TA) scheme forsynthetic bushing materials for rudder bearings and propeller shafts.The general requirements for obtaining DNV GL type approval certificate is given in class programme DNVGLCP 0338 Type approval scheme.The production site may be qualified and certified through the approval of manufacturer (AoM) scheme inaccordance with DNVGL CP 0421.The procedures and requirements described in this CP are applicable for obtaining TA certificate based onrequirements given in the Society's rules and standards, e.g.:

1) For synthetic rudder bearing bushing materials:

— DNV GL rules for classification - ships, RU SHIP Pt.3 Ch.14

2) For synthetic propeller shaft bearing materials:

— DNV GL rules for classification - ships, RU SHIP Pt.4 Ch.4.Guidance note:This class programme is not applicable for obtaining EU Marine Equipment Directive (MED) certificates. Visit www.dnvgl.com forinformation on MED certification.

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1.2 ScopeThis CP gives a description of the procedures and requirements related to documentation, design and typetesting applicable for TA of synthetic bushing materials for rudder bearings and propeller shafts.This CP does not set the design requirements for synthetic bushing materials for rudder bearings andpropeller shafts. TA is based on compliance with design requirements given in the rules and/or otherregulations and standards. The CP describes the applicable requirements and how to document compliancewith the requirements in order to obtain a TA certificate for the equipment. This includes, where relevant,technical requirements for how the type tests shall be performed.The type approval certificate will cover one grade of the actual product with the possibility to include variants.For synthetic bushing materials this means:

— grade: one chemical composition, with our without reinforcements— variants: various dimensions

Synthetic bushing materials using different chemical compositions, resins, fibres, filler material etc. areconsidered to be different grades.The Society's type approval for a synthetic bushing material is divided into four different main levels basedon the bushing material’s capability to withstand surface pressure in operational condition:

5.5 N/mm2 = type testing according to Sec.2 Table 1 and Sec.2 Table 2.

7.5 N/mm2 = type testing according to the general scheme: Sec.2 Table 1, plus testing of swell (dry/wet/dry/wet cycles) and wear testing at increased pressure: Sec.2 Table 3.

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10 N/mm2 = type testing according to the general scheme: Sec.2 Table 1, plus testing of swell (dry/wet dry/wet cycles) and wear testing at increased pressure: Sec.2 Table 3. Additionally,satisfactory service experience from rudder bearing application in minimum 2.5 years (atminimum 5.5 N/mm2) in at least two different vessels classed with the Society shall bedocumented.

Type approvals issued for surface pressures above 5.5 N/mm2 will be issued with a statement that area ofapplication will be evaluated during approval of certified products if the surface pressure exceeds 5.5 N/mm2.Further, a maximum surface pressure of 10 N/mm2 will be subject to evaluation w.r.t. service experience etc.in connection with renewal of a certificate.The type approval will normally only cover water and/or oil lubrication, however, for self-lubricating materialsthat have documented good performance in lubricated systems for several years it will be possible to applyfor an approval covering also non-lubrication (see Sec.2 [5]).The Society's type approval for a synthetic propeller shaft bearing material is given for pressure up to 0.6MPa (6 bar).The type approval certificate is normally limited to one manufacturer at one production site, however, otherarrangements may be agreed upon with the Society.Type tests as specified in Sec.2 [3], shall be carried out and verified in one of the following ways:

— at a DNV GL laboratory— at an accredited and recognized testing laboratory or a laboratory accepted by the Society— at the manufacturer’s premises in the presence of a surveyor.

The type test results shall be submitted to the Society in form of a test report according to ISO 17025 andthe additional requirements of the relevant test standard for evaluation.

1.3 ApplicationDNV GL rules for classification - ships, RU SHIP Pt.3 Ch.14 and RU SHIP Pt.4 Ch.4 require that syntheticbushing materials for rudder bearings and propeller shafts are type approved in accordance with this CP forequipment to be installed on vessels classed with the Society.A TA certificate in accordance with this CP will confirm compliance with the requirements given in the rules asspecified in [1.1]. The TA certificate will not confirm compliance with requirements given in other parts of therules. In case additional requirements given in other parts of the rules shall be covered by the TA certificate,this shall be specified in the application for TA and will be stated in the TA certificate.

1.4 Application for renewal after five (5) yearsApplication for renewal should be submitted to the Society not later than three (3) months before expiry dateof the type approval certificate.The application shall include updated type approval documentation as specified in Sec.2.Upon receipt of the application, the Society will perform a renewal assessment with main objective to verifythat the product properties, material composition and the product marking are not altered since issuance ofthe type approval certificate.Provided an approval of manufacturer certificate (see DNVGL CP 0421 Manufacturer of Fibre Reinforcements)which is still valid for at least one year is available, an exemption from the obligation concerning retentionand renewal surveys listed in the class programme DNVGL CP 0338 Type Approval scheme will typicallyapply.If there, since last issuance of the type approval certificate, has been any change in the relevant standards orin the Society’s rules, new assessment of product and type tests may be required.

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2 ReferencesStandards referred to in this document:

— ISO 9001:2008, Quality management systems - Requirements— ISO 604, Plastics - Determination of compressive properties.— ISO 175, Plastics - Methods of test for the determination of the effects of immersion in liquid chemicals.— ASTM D1141, Standard Practice for the Preparation of Substitute Ocean Water.— ISO 1817, Rubber, vulcanized - Determination of the effect of liquids.— ASTM D696, Standard Test Method for Coefficient of Linear Thermal Expansion of Plastics Between -30°C

and 30°C With a Vitreous Silica Dilatometer.— ASTM G77-05(2010), Standard Test Method for Ranking Resistance of Materials to Sliding Wear Using

Block-on-Ring Wear Test.

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3 DocumentationFor TA of synthetic bushing materials for rudder bearings and propeller shafts the following documentationshall be submitted by the manufacturer at initial type approval and updated, at renewal. The documentationshall, to the extent possible, be submitted as electronic files. The manufacturer shall keep one (1) copy oftype approval documentation in their own file. The documentation that forms the basis for the TA shall beeasily available for surveyors at the TA applicant’s premises. When documentation is submitted in paperformat, normally two copies of the documentation shall be submitted to the Society. No documentation willbe returned to the company applying for TA.The documentation shall be in the English language, if not otherwise agreed. (Please number documentationaccording to below list to facilitate review):

1) type designation, i.e. product name (grade) with list of variants to be included in and stated on the typeapproval certificate

2) name and address of the manufacturer, to be listed on type approval certificate. The following shall bespecified:

— details for all relevant production places— manufacturer’s name— mailing address— contact person— phone and fax number— e-mail and web address (if applicable)

3) basis for approval. A reference of applicable rules and standards which the product shall comply with(see [1.1])

4) product description:

— resin or matrix material used— fibre reinforcement, if any— impregnation/lubrication, if self-lubricating— isotropic or anisotropic behaviour— elastomeric or non-elastomeric type

5) field of application and special limitations of the product, including e.g.:

— operation in cold climate, possible shrinkage— arrangements for securing— installation procedures

6) product specification, technical data sheet, material safety data sheet, and engineering manualincluding:

— properties as specified in tables in Sec.2 [3] nominal values and tolerances if requested— maximum nominal surface pressure— dimensions and relations that are produced and acceptable according to the manufacturer:

— min. - max. diameter— min. - max. thickness— diameter/height (d/h) ratio— thickness/diameter (t/d) ratio— interference fitting tolerance data— other, if relevant

— acceptable mating material (shaft; type of material, roughness, hardness etc.)

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— minimum and maximum installation clearance (take into account swell, edge and thermal effects). Iftest results show less than 0.1% swell in total (non-swelling material), a minimum clearance below1.5 mm (IACS requirement) can be discussed and agreed upon

— type of lubrication(s) required, if any

— maximum service temperature and peak temperature if relevant

7) description of production processes, including standard operating procedures (SOP) 1

8) description of quality assurance system or copy of ISO 9001 certificate

9) quality plan for synthetic bushings intended to be installed on board ships 1

10) test results (from tests already carried out) with references to standards, methods etc.

11) information regarding marking of the product or packaging 1

12) in-service experience, if available

13) witnessed type test results and initial assessment report by the Society’s local office shall be submittedwhen completed

14) list of test and measuring equipment including calibration certificate.

1 To be verified by initial assessment prior to issuance of type approval certificate

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SECTION 2 GENERAL REQUIREMENTS

1 Design requirementsThe synthetic bushing materials for rudder bearings and propeller shafts shall comply with the relevantrequirements given in the rules listed in Sec.1 [1.1].

2 Requirements for production and quality control arrangementThe manufacturer should have a quality system that meets ISO 9001 standards, or equivalent. If this qualitystandard is not fulfilled, the extent of type testing and assessments will be specially considered.The quality control arrangement in production will be checked with respect to:

— control of incoming materials— scope of quality control, i.e. proof that test methods, test quantity and test equipment complies to the

applicable standard EN or ISO traceability and marking system— production records— storage condition and procedure.

3 Requirements for materialThe extent of type testing is described in the following. It shall be noted that all tests shall be carried outat temperature from 20°C and upwards. The manufacturer shall inform whether there will be any differentbehavior of the material at lower temperatures as vessels will normally operate in temperatures down to andbelow 0°C.

3.1 Extent of type tests, for all surface pressuresTable 1 General scheme for type testing, all surface pressures

Property Unit Test method 1) Number andselection of specimen

Acceptancecriteria

Definitionof

value

Level ofverification

Frequencyof

verification

COMPRESSIVE PROPERTIES

Compressive deformation

Elastomeric:max. allowabledeformation ata compressivestress equal

to 120 N/mm2

%

Test method tobe specified by

manufacturer.(ISO604, if relevant)

Isotropic: min. 5

Anisotropic: min. 10

Max. 4%defor-mation

m +2sdev

The Societywitnessof test2)

Initialrenewal

Compressive strength

Non-elastomeric:(flatwise*)

N/mm2 ISO 604

Isotropic: min. 5

Anisotropic: min. 10

Min.100 N/

mm2

m -2sdev


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Acceptancecriteria

Definitionof

value


Frequencyof

verification

Non-elastomeric:(edgewise**)Only required

for stripsand staves

Min.85 N/mm2

m -2sdev


Compressive modulus

Non-elastomeric:(flatwise*)

N/mm2 ISO 604

Isotropic: min. 5Anisotropic: min. 10

Min.1000

N/mm2

m -2sdev


Initialrenewal

EFFECT OF WATER

Water Swelling3)

20°Cand

80°C%

ISO 175 4 weeksin substitute ocean

water (ASTM D1141)at 20°C and 80°C.

Min. 3 specimen ateach temperature.

Samples, tubesegment or flat piece

with dimension;50x50xt mm, t ismin. 4 mm or the

min. thickness of thebushing produced

(will be stated on thecertificate).Testing

immediatelyafter extraction(wet condition)

VolumetricNon-

swelling:

-if <0.1%.

Swelling:

-if 0.1 tomax. 3%

Allresultsbelow

require-ment

The Societywitness of

start-up andcompletionof test 2)

Initial

Water resistance

Elastomeric %

Max. allowabledeformation ata compressive

stress equal to 120N/mm2, after 4

weeks in substituteocean water (ASTM

D1141) at 20°C


Max. 4%defor-mation

m +2sdev


compressiontest2)

Initial

Non-elastomeric %

ISO 604Compression testafter 4 weeks insubstitute ocean

water (ASTMD1141) at 20°C


Min. 80%retention

ofspecifiedstrength

andmodulus

m -2sdev


compressiontest2)

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Acceptancecriteria

Definitionof

value


Frequencyof

verification

EFFECT OF OIL3)

Oil swelling20°C

%ISO 175

4 weeks in oil no.3(ISO 1817) at 20°C

min. 3specimenwith dimension;50x50xt mm, t ismin. 4 mm or the

min. thickness of thebushing produced

(will be stated on thecertificate).Testing

immediatelyafter extraction(wet condition)

VolumetricNon-

swelling:

if < 0.1%

Swelling

if 0.1 tomax. 3%

Allresultsbelow

require-ment


start-up andcompletionof test 2)

Initial

EFFECT OF TEMPERATURE

Temperature resistance

Elastomeric %

Max. allowabledeformation at a

compressive stressequal to 120 N/mm2,

after heating thetest sample up to atemperature of 50°C


Max. 4%defor-mation

m +2sdev


compressiontest2)

Initial

Non-elastomeric %

ISO 604Compression testafter heating the

test sample up to atemperature of 50°C

Isotropic:min. 5

Anisotropic:

min. 10

Min. 80%retention

ofspecifiedstrength

andmodulus

m -2sdev


compressiontest2)

Initial

Thermal expansion

(flatwise*) and(edgewise**)

mm/mm°C

ASTM D696 - msv - - Initial

See end of Table 3 for notes and legends

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3.2 Extent of type tests, for surface pressures up to 5.5 MpaTable 2 Surface pressure up to 5.5 N/mm2

Property Unit Test method 1)Number andselection ofspecimen

Acceptancecriteria

Definitionof value


Frequency ofverification

WEAR

Wear

See theSociety’s

weartest

below

See the Society’swear test. Othertest methods canbe agreed uponprior to testing.

See theSociety’s wear

test below

Wear ratetest shall

demonstratethat a service

of min. 10years in rudderapplication canbe expected.

-


start-up andcompletion

of test

Initial

FRICTION

Dynamic(only onecycle is

sufficient)

-

Static

Recorded by asimple, recognised

method at both20°C and 80°Cpreferably asa function of

pressure orminimum attwo different

surface pressures(max. and twice

the max.).

Min. 3 specimenat each

temperature

and surfacepressure.

Max. 0.25All results

belowrequirement

The Societywitness oftest set-up and

recording oftest results

Initial

See end of Table 3 for notes and legends

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3.3 Extent of type tests, for surface pressures from 5.5 up to 10 MpaTable 3 Increased surface pressure above 5.5 N/mm2 and up to max. 10 N/mm2


Acceptancecriteria

Definitionof value


Frequencyof

verification

EFFECT OF WATER/DRYING 3)

Waterswelling %

ISO 175 wet/dry/wet/.

cycle; 3 days wet+ 3 days dry for

4 weeks in

substitute oceanwater (ASTM D1141)

at 20°C. Shallinitiate and end with

3 days wet.

Min. 3 specimen,tube segment orflat piece with

dimension; 50×50×tmm, t is min. 4mm or the min.thickness of the

bushing produced(will be stated onthe certificate).

Testing immediatelyafter immersion(wet condition)

Volumetricnon-swelling:

-if < 0.1%

Swelling:

-if 0.1 tomax. 3%

All resultsbelow

requirement

TheSocietywitness

of start-up and

completionof test 2)

Initial

WEAR

Wear

See theSociety’s

weartest

procedure

See the Society’swear test procedure.

See the Society’swear test procedure

Wear ratetest shall

demonstratethat a service

of min.10 yearsin rudder

applicationcan be

expected.

-

TheSocietywitness

of start-up and

completionof test

Initial

FRICTION

Dynamic -

Static -

Coefficient of frictionto be recorded by arecognised method:

20°C: During/inconnection with theSociety’s wear test.I.e. two differentsurface pressures(max. and twicethe max.) and

both dry and wetcondition. 80°C: Bya simple, recognised

method at twodifferent surface

pressures (max. andtwice the max.).

20°C:as per the

Society‘s wear test

procedure

80°C:

min. 3

specimen ateach pressure.


belowrequirement

TheSociety'switness oftest set-up and

recordingof testresults.

Initial

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Acceptancecriteria

Definitionof value


Frequencyof

verification

The following notes and legends applies to Table 1, Table 2 and Table 3:

1) other standards may be accepted by the Society prior to testing2) report from independent laboratory may be acceptable3) swelling of 3% and more will in general not be accepted

* flatwise - perpendicular to sheet plane

** edgewise - parallel to sheet plane.

Legend:

msv: manufacturer’s specified value.

m-2sdev: mean - 2 standard deviation of Type Test results.

m+2sdev: mean + 2 standard deviation of Type Test results.

Initial: Initial Assessment

Retention: Periodical Assessment, carried out after two (2) years

Renewal: Periodical Assessment, carried out after five (5) years

4 Wear testing procedure for synthetic rudder bearing bushingmaterialsOther dimensions, parameters than listed below may be accepted by the Society after agreement, prior totesting.Test set-up consisting of a:

— oscillating shaft = diameter (dsh) = 100 mm— sample shall be a fixed bearing segment = shall cover minimum 50° of the shafts circumference (width)

with a length of the bearing; hb = 1.2 dsh (length max. 120 mm for a 100 mm shaft and min. 80 mm) (iflarger samples shall be used, keep the same relation). The bearing diameter shall be db = dsh + 1 mm oraccording to manufacturer's recommendations

— Seawater lubrication facility.

Test parameters:

— oscillating shaft = ± 15°— surface pressure = Testing shall be carried out at the requested surface pressure (max. 10 N/mm2).

Additionally, testing shall be carried out at a surface pressure two times the requested pressure (i.e. max.20 N/mm2)

— lubrication = both dry and artificial seawater.— air temperature = 20°C— velocity = velocity of 3.5 mm/s— movement = the shaft movement shall go on continuously at the requested surface pressure. At surface

pressures above the requested level, a pause/break may be allowed in periods up to 10 s at each pass ofcentreline, upon agreement with the Society prior to starting the testing and will be stated as a limitationto applicable PV (Pressure and Velocity - heat generation)

— actual running time/duration = until stable wear rate has been established (minimum 192 hours at 3.5mm/s) or maximum 850 hours (excluding disassembling and pauses/breaks). For lower velocities and/orlonger pauses/breaks, the duration shall be increased accordingly.

Mating material:

— type = stainless steel

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— hardness = max. 220 HV5— mating materials surface roughness = fine turned to Ra = 0.8 µm— clearances = db = dsh + 1 mm, hence max. 1 mm on diameter or according to manufacturer's

recommendations.

Parameters to be recorded:

— wear shall be measured on bushing as well as on the liner/shaft, continuously or regularly. If regularly,wear to be measured by disassembling every 48 hours until demonstrated by minimum four points ofmeasurements that a stable wear rate is achieved. The following shall be presented both tabulated andgraphically:

— wear vs. time (mm/h) and pressure— wear vs. test cycle— wear vs. kilometres of travel— coefficient of friction shall be measured (continuously/regularly) until the wear rate has stabilised at 20°C.

Coefficient of friction vs time and pressure to be presented both tabulated and graphically— all quantified parameters to be measured— thermocouple, if relevant (shall coordinate thermic expansion and measured wear, in order to distinguish

these two parameters.

Swell due to thermal expansion and/or water swell shall be taken into account when specifying wear.

5 Approval for use in non-lubrication (dry-running) applicationsThis section applies only to synthetic rudder bearing bushing materials manufactured as self-lubricationtypes, i.e. they include fillers or similar that promotes self-lubrication. The manufacturer's technical datasheet or product description shall clearly state that the material is manufactured as, and suitable for, self-lubrication.Initially, the manufacturer may apply for dry-running up to a surface pressure of 5.5 N/mm2. Whensatisfactory performance at 5.5 N/mm2 has been documented for the bushing material in service for aminimum 2.5 years, plus testing according to Table 2, a surface pressure of 7.5 MPa may be applied for, etc.In order to include applications without water and/or oil lubrication, i.e. dry-running, the following additionsshall be made to the Society's wear testing procedure given in [4]:

— in dry condition only; continuously or regularly monitoring of temperature in the bushing material close tothe contact surface

— the running time/duration of the wear test shall be as stated in [4], however, also a stable temperatureshall be established before test is ended

— the bushing temperature shall not exceed the maximum service temperature set by the manufacturer, andin any case it shall not exceed:

— for non-elastomeric materials; heat distortion temperature (HDT) –20°C— for elastomeric materials; 50°C, or subject to evaluation for each case.

As an example, the following may be stated on the front page of the type approval certificate, when dry-running is included:“Maximum surface pressure 5.5 MPa for the synthetic bearing against steel, non-lubricated, and maximum10 MPa water or oil lubricated. The type approval is valid only when the installation/application of the productis according to the DNV GL rules and the manufacturer's specification.”

6 Approval of synthetic propeller shaft bearing materialsThere are in principle three alternative ways of obtaining a type approval for propeller shaft bearingmaterials:

— compliance with this class programme— good and well documented service experience in conventional vessels for minimum 2 years, or

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— based on a test programme developed by the manufacturer, evaluated and approved by the Society. Thetest programme shall address low, medium and high speed running, potential high surface load peaks inslow running mode etc.

7 Wear testing procedure for synthetic propeller shaft bearingmaterialsWear test for synthetic propeller shaft bearing materials with continuous motion (on the basis of ASTM G77):

— mating material: shaft made of stainless steel (about HRC 50)— diameter of shaft: the shaft diameter is depending on the bearing size but it shall be ≥ 35 mm— motion of shaft: continuous gliding— circumferential velocity: 6 m/s for oil or water lubrication, and 3 m/s for grease lubrication— lubrication: sea water (room temperature) and mineral oil (80°C), grease (80°C) if applicable— surface roughness: Ra = 0.5 mm— interface pressure: min. 0.6 MPa but in case of higher surface pressure it will be stated on the certificate— duration of test: until coefficient of wear remains constant (at least 192 h, not exceeding 840 h)— in order to obtain mixed lubrication, the test shall be interrupted every 8 hours.— dimensions of test sample.

Figure 1 Test sample dimensions

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Parameters to be recorded:

— wear shall be measured on bushings as well on the shaft, continuously or regularly. If regularly, wear tobe measured by disassembling every 48 hours until a constant wear rate has been achieved (minimum offour points of measurements). The measurements shall be presented both tabulated and graphically.

— wear vs. time (mm/h) and pressure— coefficient of friction— test distance [h]— temperature of test sample during test cycle.

8 Requirements for marking of productThe product or package shall be marked. The marking shall at least include the following information:

— product name— manufacturer’s name and address or trade mark— storage instruction— production date/batch number— quality guarantee period, if any.

The marking shall be carried out in such a way that it is visible, legible and indelible. The marking of productshall enable traceability to the Society's type approval certificate.

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APPENDIX A GENERAL SCHEME FOR TYPE TESTING

1 All surface pressures – entry of type test resultsTable 1 General scheme for type testing, all surface pressures – type test results

Property Test method Acceptance criteria Definitionof value

Manufacturer’sSpecification

Type Testresults

COMPRESSIVE PROPERTIES

Compressive deformation

Elastomeric:Max. allowable

deformation at a

compressive stress

equal to 120 N/mm2

Test method tobe specified.

Max. 4%deformation

m + 2sdev

Compressive strength

Non Elastomeric:(flatwise*)

Min. 120 N/mm2 m - 2sdev

Non Elastomeric:(edgewise**)

Only required forstrips and staves

ISO 604

Min. 85 N/mm2 m - 2sdev

Compressive Modulus

Non Elastomeric:(flatwise*)

ISO 604 Min. 1500 N/mm2 m - 2sdev

EFFECT OF WATER

Water Swelling

20°C

80°C.

ISO 1754 weeks insubstitute

ocean water(ASTM D1141)

VolumetricNon swelling:

-if < 0.1%

Swelling:

-if 0.1 to max. 3%

All resultsbelow

requirement

Water resistance

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Type Testresults

Elastomeric

Max. allowabledeformation at a

compressivestress equal to120 N/mm2,

after 4 weeks in

substitute ocean

water (ASTMD1141)

at 20°C

Max. 4%deformation

m + 2sdev

Non elastomeric

ISO 604Compression test

after 4 weeks in

substitute ocean

water (ASTMD1141) at 20°C

Min. 80% retentionof specified

strength andmodulus

m - 2sdev

EFFECT OF OIL

Oil swelling

ISO 1754 weeks in oil

no.3 (ISO 1817)

at 20°C

VolumetricNon swelling if

< 0.1%

Swelling if

0.1 to max. 3%

All resultsbelow

requirement

EFFECT OF TEMPERATURE

Temperature resistance

Elastomeric

Max. allowabledeformation ata compressivestress equal to

120 N/mm2, afterheating the testsample up to a

temperature of 50°C

Max. 4%deformation

m + 2sdev

Non elastomeric

ISO 604Compression test

after heating thetest sample up to atemperature of 50°C

Min. 80% retentionof specified

strength andmodulus

m - 2sdev

Thermal expansion

(flatwise*)

(edgewise**)ASTM D696 msv

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2 All surface pressures – up to 5.5 N/mm2 - entry of type testresultsTable 2 Surface pressure up to 5.5 N/mm2 - type test results



Type Testresults

WEAR

Wear

See the Society’swear test procedure.Other test methodscan be agreed upon

prior to testing

Wear rate testshall demonstratethat a service ofmin. 10 years in

rudder applicationcan be expected.

-

FRICTION, DRY

Dynamic SurfacePressure

Pmax.20°C

2 x Pmax

Pmax

80°C.2 x Pmax

Recorded by a simple,recognised method,

preferably as afunction of pressure or

minimum at two

different surface

pressures (Pmax andtwice the Pmax),dry conditions.


belowrequirement

Static SurfacePressure

Pmax.20°C

2 x Pmax

Pmax

80°C.2 x Pmax

Recorded by a simple,recognised method,

preferably as afunction of pressure or

minimum at two

different surface

pressures (Pmax andtwice the Pmax),dry conditions.


belowrequirement

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3 All surface pressures – above 5.5 N/mm2 and up to max. 10 N/mm2 - entry of type test resultsTable 3 Increased surface pressure above 5.5 N/mm2 and up to max. 15 N/mm2 - type testresults

Property Test method Acceptancecriteria

Definitionof value


Type Testresults

EFFECT OF WATER/DRYING

Water swelling

ISO 175wet/dry/wet/.

cycle; 3 days wet

+ 3 days dry for 4weeks in substitute

ocean water(ASTM D1141)at 20°C. Shall

initiate and endwith 3 days wet.

VolumetricNon-swelling:

-if < 0.1%

Swelling:

-if 0.1 tomax. 3%.

All resultsbelow

requirementSample

dimension tobe reported.

WEAR

Wear See the Society’swear test.

Wear rate testshall demonstrate

that a serviceof min. 10

years in rudderapplication canbe expected.

-

FRICTION

Dynamic SurfacePressure

Dry/ Wetcondition

DryPmax.

Wet

Dry20°C

2 x PmaxWet

DryPmax

Wet

Dry80°C.

2 x PmaxWet

Coefficient offriction to berecorded by a

recognised method:20°C:

as per the Society‘stest method

80°C:

By a simple,recognised method

at two differentsurface pressures(max. and twice

the max.).


belowrequirement

Static SurfacePressure

Dry/ Wetcondition

App

endi

x A


DNV GL AS

Property Test method Acceptancecriteria

Definitionof value


Type Testresults

DryPmax.

Wet

Dry20°C

2 x PmaxWet

DryPmax

Wet

Dry80°C.

2 x PmaxWet

Coefficient offriction to berecorded by a

recognised method:20°C:

as per the Society‘swear test procedure

80°C:

By a simple,recognised method

at two differentsurface pressures(max. and twice

the max.).


belowrequirement

Cha

nges

– h

isto

ric


DNV GL AS

CHANGES – HISTORICThere are currently no historical changes for this document.

DNV GLDriven by our purpose of safeguarding life, property and the environment, DNV GL enablesorganizations to advance the safety and sustainability of their business. We provide classification andtechnical assurance along with software and independent expert advisory services to the maritime,oil and gas, and energy industries. We also provide certification services to customers across a widerange of industries. Operating in more than 100 countries, our 16 000 professionals are dedicated tohelping our customers make the world safer, smarter and greener.

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DNVGL-CP-0081 Synthetic bearing bushing materials

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