Industrial Shaft Seals Cataloque

7/16/2019 Industrial Shaft Seals Cataloque

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Industrial shaft seals


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SKF, CR, DURATEMP, SPEEDI-SLEEVE and WAVE are registeredtrademarks of the SKF Group.

SKF Group 2012The contents of this publication are the copyright of the publisherand may not be reproduced (even extracts) unless prior written per-mission is granted. Every care has been taken to ensure the accuracyof the information contained in this publication but no liability can beaccepted for any loss or damage whether direct, indirect or conse-quential arising out of the use of the information contained herein.

The data in this publication may differ from that provided in earlierpublications because of redesign, technological developments orrevised methods of calculation. SKF reserves the right to make

continuing improvements to SKF products without prior notice withrespect to materials, design and manufacturing methods, as well aschanges necessitated by technological developments.

PUB SE/P1 10919/1 EN January 2012

This publication supersedes publication 5300.

SI conversion table

Quantity Unit Conversion

Length inch 1 mm 0.039 in. 1 in. 25,40 mmfoot 1 m 3.281 ft. 1 ft. 0,3048 m

yard 1 m 1.094 yd. 1 yd. 0,9144 mmile 1 km 0.6214 mile 1 mile 1,609 kmVelocity, foot per second 1 m/s 3.28 ft/s 1 ft/s 0,30480 m/sspeed foot per minute 1 m/s 196.8504 ft/min 1 ft/min 0,00508 m/s

mile per hour 1 km/h 0.6214 mile/h 1 mile/h 1,609 km/h(mph) (mph)

Force pound-force 1 N 0.225 lbf. 1 lbf. 4,4482 N

Pressure, pounds per 1 MPa 145 psi 1 psi 6,8948 103 Pastress square inch

Temperature (degree) Celsius tC = 0,555 (tF 32) Fahrenheit tF = 1,8 tC + 32


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Product data general1 . . . . . . . . . . . . . . . . . . . . . . . . . 11

Radial shaft seals2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Cassette seals3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317

Wear sleeves4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323

Track pin seals5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369

Metal face seals6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375

V-ring seals7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385

Axial clamp seals8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459

Product index9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 470

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Contents

Foreword. . . . . . . . . . . . . . . . . . . . . . . . . . . 5

SKF the knowledgeengineering company . . . . . . . . . . . . . . . . 6

SKF industrial shaft sealsand accessories . . . . . . . . . . . . . . . . . . . . 10

Product data general1 . . . . . . . . . . . . . 11

Industrial shaft seals. . . . . . . . . . . . . . . 12Profile overview selection . . . . . . . . . . . . 13

Radial shaft seals . . . . . . . . . . . . . . . . . 13Wear sleeves . . . . . . . . . . . . . . . . . . . . 15Axial shaft seals . . . . . . . . . . . . . . . . . . 16

Selection of seal design and material . . . 17

Grease retention . . . . . . . . . . . . . . . . . 17Oil retention . . . . . . . . . . . . . . . . . . . . . 18Contaminant exclusion . . . . . . . . . . . . 19Retention and exclusion . . . . . . . . . . . . 20Separating two liquids . . . . . . . . . . . . . 21Circumferentialand rotational speed . . . . . . . . . . . . . . 22Pressure differentials . . . . . . . . . . . . . . 23Limited space . . . . . . . . . . . . . . . . . . . . 24Installation restrictions . . . . . . . . . . . . 25Arrangement . . . . . . . . . . . . . . . . . . . . 26

Counterface design . . . . . . . . . . . . . . . 27Axial movement . . . . . . . . . . . . . . . . . . 28

Seal materials . . . . . . . . . . . . . . . . . . . . . 29Cases and inserts . . . . . . . . . . . . . . . . . 29Garter springs . . . . . . . . . . . . . . . . . . . 29SKF Bore Tite Coating . . . . . . . . . . . . . 29Adhesives and bonding agents . . . . . . 29Sealing lip materials . . . . . . . . . . . . . . 30

Wear resistance . . . . . . . . . . . . . . . . . . . . 33Operating temperatures . . . . . . . . . . . . . 34Chemical resistance . . . . . . . . . . . . . . . . . 35

Storage and handling of seals . . . . . . . . . 44General . . . . . . . . . . . . . . . . . . . . . . . . 44Storage . . . . . . . . . . . . . . . . . . . . . . . . 44Cleaning and maintenance . . . . . . . . . 45

Radial shaft seals2 . . . . . . . . . . . . . . . . . . 47General . . . . . . . . . . . . . . . . . . . . . . . . . . 50Outside diameter design . . . . . . . . . . . . . 54

SKF Bore Tite Coating . . . . . . . . . . . . . 54Garter springs . . . . . . . . . . . . . . . . . . . . . 55

Dimensions . . . . . . . . . . . . . . . . . . . . . . . 55Tolerances . . . . . . . . . . . . . . . . . . . . . . 55Sealing lip design . . . . . . . . . . . . . . . . . . . 57Auxiliary lips . . . . . . . . . . . . . . . . . . . . . . . 58Coaxiality and runout . . . . . . . . . . . . . . . . 59

Coaxiality . . . . . . . . . . . . . . . . . . . . . . . 59Runout . . . . . . . . . . . . . . . . . . . . . . . . . 61

Axial movement . . . . . . . . . . . . . . . . . . . . 63Permissible speeds . . . . . . . . . . . . . . . . . 63Lubrication. . . . . . . . . . . . . . . . . . . . . . . . 65

Lubrication of paired arrangements . . 65

Friction . . . . . . . . . . . . . . . . . . . . . . . . . . . 66Chemical and thermal resistance . . . . . . . 67Seals under pressure . . . . . . . . . . . . . . . . 69Shaft requirements . . . . . . . . . . . . . . . . . 70

General . . . . . . . . . . . . . . . . . . . . . . . . 70Tolerances . . . . . . . . . . . . . . . . . . . . . . 70Surface roughness . . . . . . . . . . . . . . . . 70Surface finish . . . . . . . . . . . . . . . . . . . . 72Hardness and surface treatment . . . . . 72Lead-in chamfers . . . . . . . . . . . . . . . . 72

Housing bore requirements . . . . . . . . . . . 74

General . . . . . . . . . . . . . . . . . . . . . . . . 74Metal-reinforced seals . . . . . . . . . . . . . 74Seals without metal-reinforcement . . . 74Tolerances . . . . . . . . . . . . . . . . . . . . . . 76Surface roughness . . . . . . . . . . . . . . . . 76

Seal installation, general industrialapplications . . . . . . . . . . . . . . . . . . . . . . . 77

General . . . . . . . . . . . . . . . . . . . . . . . . 77Seal installation, heavy industrialapplications . . . . . . . . . . . . . . . . . . . . . . . 79

Metal-reinforced seals . . . . . . . . . . . . . 79

Seals without metal reinforcement . . . 80Split seals . . . . . . . . . . . . . . . . . . . . . . . 80Cover plates . . . . . . . . . . . . . . . . . . . . . 82Multiple HS seal installations . . . . . . . . 83Multiple HDS seal installations . . . . . . 84PTFE seals . . . . . . . . . . . . . . . . . . . . . . 85

Protecting the counterface surfaceagainst corrosion . . . . . . . . . . . . . . . . . . . 87Removal . . . . . . . . . . . . . . . . . . . . . . . . . . 87Replacement . . . . . . . . . . . . . . . . . . . . . . 87Designation system . . . . . . . . . . . . . . . . . 88

Metric radial shaft seals . . . . . . . . . . . . 88Inch-size radial shaft seals. . . . . . . . . . 88

Assortment and availability . . . . . . . . . . . 88

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Seals for general industrialapplications . . . . . . . . . . . . . . . . . . . . . . . 92

HMS5 and HMSA10 seals . . . . . . . . . . 92CRW1, CRWA1, CRWH1and CRWHA1 seals . . . . . . . . . . . . . . . 100

CRW5 and CRWA5 seals . . . . . . . . . . . 156HDW1 seals . . . . . . . . . . . . . . . . . . . . . 160CRS1, CRSH1, CRSA1and CRSHA1 seals . . . . . . . . . . . . . . . . 162PTFE radial shaft seals . . . . . . . . . . . . 170HM and TL seals for greaselubricated applications . . . . . . . . . . . . . 174X seals, sealing againsthousing bore . . . . . . . . . . . . . . . . . . . . 188

Seals for heavy industrialapplications . . . . . . . . . . . . . . . . . . . . . . . 198

General . . . . . . . . . . . . . . . . . . . . . . . . 198Metal-cased seals . . . . . . . . . . . . . . . . 198Rubber outside diameter seals . . . . . . 203Additional design features . . . . . . . . . . 207Size options of metal-cased HDS sealsand all-rubber HS seals . . . . . . . . . . . . 211Product tables . . . . . . . . . . . . . . . . . . . 212

Cassette seals3 . . . . . . . . . . . . . . . . . . . . . 317General . . . . . . . . . . . . . . . . . . . . . . . . . . 318Design features . . . . . . . . . . . . . . . . . . . . 319

Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . 319Installation . . . . . . . . . . . . . . . . . . . . . . . . 319SKF Mudblock seal designsMUD5 and MUD7. . . . . . . . . . . . . . . . . . . 320

Wear sleeves4 . . . . . . . . . . . . . . . . . . . . . 323General . . . . . . . . . . . . . . . . . . . . . . . . . . 324SKF SPEEDI-SLEEVE . . . . . . . . . . . . . . . 325

Features . . . . . . . . . . . . . . . . . . . . . . . . 325Size range . . . . . . . . . . . . . . . . . . . . . . 325SKF SPEEDI-SLEEVE Gold . . . . . . . . . 326

Test results. . . . . . . . . . . . . . . . . . . . . . 326Selecting the right size . . . . . . . . . . . . . 326Installing SKF SPEEDI-SLEEVE . . . . . . 327Removing SKF SPEEDI-SLEEVE . . . . . 329Product tables . . . . . . . . . . . . . . . . . . . 330

Wear sleeves for heavyindustrial applications (LDSLV) . . . . . . . . 352

General . . . . . . . . . . . . . . . . . . . . . . . . 352Designs and features . . . . . . . . . . . . . . 353Using LDSLV designs . . . . . . . . . . . . . . 354Installation . . . . . . . . . . . . . . . . . . . . . . 354

Removal . . . . . . . . . . . . . . . . . . . . . . . . 354Product tables . . . . . . . . . . . . . . . . . . . 356

Track pin seals5 . . . . . . . . . . . . . . . . . . . . 369General . . . . . . . . . . . . . . . . . . . . . . . . . . 370Features and benefits . . . . . . . . . . . . . . . 370Product tables . . . . . . . . . . . . . . . . . . . . . 372

Metal face seals6 . . . . . . . . . . . . . . . . . . . 375General . . . . . . . . . . . . . . . . . . . . . . . . . . 376Design features . . . . . . . . . . . . . . . . . . . . 376Lubricant requirements . . . . . . . . . . . . . . 377Permissible operating conditions . . . . . . . 378Contaminants . . . . . . . . . . . . . . . . . . . . . 378Installing HDDF seals . . . . . . . . . . . . . . . . 378

General . . . . . . . . . . . . . . . . . . . . . . . . 378Housing and seal preparation . . . . . . . 378Installation procedure . . . . . . . . . . . . . 379Product tables . . . . . . . . . . . . . . . . . . . 380

V-ring seals7 . . . . . . . . . . . . . . . . . . . . . . 385General . . . . . . . . . . . . . . . . . . . . . . . . . . 386Features . . . . . . . . . . . . . . . . . . . . . . . . . . 386Materials . . . . . . . . . . . . . . . . . . . . . . . . . 387Standard designs . . . . . . . . . . . . . . . . . . . 388Main V-ring functions . . . . . . . . . . . . . . . 389Other V-ring functions . . . . . . . . . . . . . . . 390Sliding velocities . . . . . . . . . . . . . . . . . . . 391Coaxiality and runout . . . . . . . . . . . . . . . . 392Misalignment . . . . . . . . . . . . . . . . . . . . . . 392

Counterface . . . . . . . . . . . . . . . . . . . . . . . 393Counterface treatment . . . . . . . . . . . . 393Additional counterface information . . . 393

Shaft requirements . . . . . . . . . . . . . . . . . 395Installing V-rings . . . . . . . . . . . . . . . . . . . 395Product tables . . . . . . . . . . . . . . . . . . . . . 396MVR axial shaft seals . . . . . . . . . . . . . . . . 452

General . . . . . . . . . . . . . . . . . . . . . . . . 452Advantages and user benefits . . . . . . . 452Design and material . . . . . . . . . . . . . . . 452Temperature range . . . . . . . . . . . . . . . 452

Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . 452Installation . . . . . . . . . . . . . . . . . . . . . . 453Product tables . . . . . . . . . . . . . . . . . . . 454

Axial clamp seals8 . . . . . . . . . . . . . . . . . . 459General . . . . . . . . . . . . . . . . . . . . . . . . . . 460Designs . . . . . . . . . . . . . . . . . . . . . . . . . . 460Design of the sealing arrangement . . . . . 461Installation instructions . . . . . . . . . . . . . . 462Product tables . . . . . . . . . . . . . . . . . . . . . 464

Product index9 . . . . . . . . . . . . . . . . . . . . . 470

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The SKF brand now stands for more thanever before, and means more to you as avalued customer.

While SKF maintains its leadership as ahigh-quality bearing manufacturer through-out the world, new dimensions in technicaladvances, product support and services haveevolved SKF into a truly solutions-orientedsupplier, creating greater value forcustomers.

These solutions enable customers to im-prove productivity, not only with break-through application-specific products, but

also through leading-edge design simulationtools and consultancy services, plant assetefficiency maintenance programmes, andthe industrys most advanced supply man-agement techniques.

The SKF brand still stands for the very bestin rolling bearings, but it now stands formuch more.

SKF the knowledge engineering

company

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Foreword

This edition of the Industrial shaft seals cataloguesupersedes the one published in 2006 (publi-cation number 5300). For this new edition,numerous revisions, additions and enhancements

have been made to provide an even more com-prehensive guide. Though the aim of this cata-logue is to cover a very wide seal assortment, itstill only includes a selection of our completeassortment of shaft seals and accessories.

The data in this catalogue may differ fromthat provided in earlier catalogues because ofredesign, technological developments or revisedmethods of calculation. SKF reserves the rightto make continuing improvements to SKF prod-ucts without prior notice with respect to materi-

als, design and manufacturing methods, as wellas changes necessitated by technologicaldevelopments.

Catalogue overview

In order to emphasize the importance of studyingthe operating conditions of each application be-fore selecting a sealing solution, this catalogueoutlines the most important factors to consider.These are provided in the chapter Product data general, along with basic shaft and housing

bore requirements.SKF industrial shaft seals and accessories

are divided into three main groups: radial shaftseals, axial shaft seals and wear sleeves. Differ-ent seal types within these groups are describedwith their respective design, materials andapplications.

Product descriptions are followed by producttables. It should be noted, however, that thesetables only cover a selection of available sizes.Always contact your SKF sales representative for

complete and updated availability information.

The SKF Interactive Engineering Catalogue

SKF provides this catalogue in electronic format,the SKF Interactive Engineering Catalogue,online at www.skf.com.

Units

The units in this catalogue are in accordance withISO (International Organization for Standard-ization) standard 1000:1992, and SI (SystmeInternational dUnits).

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SKF the knowledgeengineering company

From the company that invented the self-align-ing ball bearing more than 100 years ago, SKFhas evolved into a knowledge engineering com-pany that is able to draw on five technology

platforms to create unique solutions for itscustomers. These platforms include bearings,bearing units and seals, of course, but extend toother areas including: lubricants and lubricationsystems, critical for long bearing life in manyapplications; mechatronics that combine mech-anical and electronics knowledge into systemsfor more effective linear motion and sensorizedsolutions; and a full range of services, from de-sign and logistics support to condition monitor-ing and reliability systems.

Though the scope has broadened, SKF con-tinues to maintain the worlds leadership in thedesign, manufacture and marketing of rollingbearings, as well as complementary productssuch as radial seals. SKF also holds an increas-ingly important position in the market for linearmotion products, high-precision aerospacebearings, machine tool spindles and plant main-tenance services.

The SKF Group is globally certified to ISO14001, the international standard for environ-mental management, as well as OHSAS 18001,the health and safety management standard.

Individual divisions have been approved forquality certification in accordance with ISO 9001and other customer specific requirements.

With over 100 manufacturing sites worldwideand sales companies in 70 countries, SKF is atruly international corporation. In addition, our15 000 distributors and dealers around theworld, an e-business marketplace, and a globaldistribution system, put SKF closer to customersto enhance their ability to quickly supply bothproducts and services. In essence, SKF solutions

are available wherever and whenever customersneed them. Overall, the SKF brand and the cor-poration are stronger than ever. As the know-ledge engineering company, we stand ready toserve you with world-class product competen-cies, intellectual resources, and the vision tohelp you succeed.

SealsBearingsand units

Lubricationsystems

Mechatronics Services

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Evolving by-wire technologySKF has a unique expertise in the fast-growing by-wire technology, from fly-by-wire,to drive-by-wire, to work-by-wire. SKF pioneered practical fly-by-wire technology and

is a close working partner with all aerospace industry leaders. As an example, virtuallyall aircraft of the Airbus design use SKF by-wire systems for cockpit flight control.

SKF is also a leader in automotive by-wiretechnology, and has partnered with automotiveengineers to develop two concept cars, whichemploy SKF mechatronics for steering and

braking. Further by-wire development has ledSKF to produce an all-electric forklift truck,which uses mechatronics rather thanhydraulics for all controls.

Airbus photo: exm company, H. Gouss

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Harnessing wind powerThe growing industry of wind-generated electricpower provides a source of clean, green electric-ity. SKF is working closely with global industryleaders to develop efficient and trouble-free tur-bines, providing a wide range of large, highlyspecialized bearings and condition monitoringsystems to extend equipment life of wind farmslocated in even the most remote and inhospitableenvironments.

Working in extreme environmentsIn frigid winters, especially in northern countries,extreme sub-zero temperatures can cause bear-ings in railway axleboxes to seize due to lubrica-tion starvation. SKF created a new family ofsynthetic lubricants formulated to retain their lu-brication viscosity even at these extreme tem-peratures. SKF knowledge enables manufactur-ers and end user customers to overcome the

performance issues resulting from extreme tem-peratures, whether hot or cold. For example, SKFproducts are at work in diverse environmentssuch as baking ovens and instant freezing in foodprocessing plants.

Developing a cleaner cleanerThe electric motor and its bearings are the heart

of many household appliances. SKF works closelywith appliance manufacturers to improve theirproducts performance, cut costs, reduce weight,and reduce energy consumption. A recent exam-ple of this cooperation is a new generation ofvacuum cleaners with substantially more suction.SKF knowledge in the area of small bearing tech-nology is also applied to manufacturers of powertools and office equipment.

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Maintaining a 350 km/h R&D labIn addition to SKFs renowned research and de-velopment facilities in Europe and the UnitedStates, Formula One car racing provides a uniqueenvironment for SKF to push the limits of bearingtechnology. For over 60 years, SKF products, en-gineering and knowledge have helped make Scu-deria Ferrari a formidable force in F1 racing. (Theaverage racing Ferrari utilizes around 150 SKFcomponents.) Lessons learned here are appliedto the products we provide to automakers andthe aftermarket worldwide.

Delivering Asset Efficiency OptimizationThrough SKF Reliability Systems, SKF provides acomprehensive range of asset efficiency productsand services, from condition monitoring hard-ware and software to maintenance strategies,engineering assistance and machine reliabilityprogrammes. To optimize efficiency and boostproductivity, some industrial facilities opt for anIntegrated Maintenance Solution, in which SKF

delivers all services under one fixed-fee, per-formance-based contract.

Planning for sustainable growthBy their very nature, bearings make a positive

contribution to the natural environment, enab-ling machinery to operate more efficiently, con-sume less power, and require less lubrication. Byraising the performance bar for our own prod-ucts, SKF is enabling a new generation of high-efficiency products and equipment. With an eyeto the future and the world we will leave to ourchildren, the SKF Group policy on environment,health and safety, as well as the manufacturingtechniques, are planned and implemented tohelp protect and preserve the earths limited nat-

ural resources. We remain committed to sustain-able, environmentally responsible growth.

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SKF industrial shaft seals and accessories

Radial shaft seals

Cassette seals

Seals for generalindustrial applications

Seals for heavyindustrial applications

Wear sleeves

SKF SPEEDI-SLEEVE

Wear sleeves for heavyindustrial applications

Axial shaft seals

Track pin seals

Metal face seals

V-ring seals

Axial clamp seals

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1Product data general

Industrial shaft seals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Profile overview selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Radial shaft seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Wear sleeves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Axial shaft seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Selection of seal design and material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Grease retention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Oil retention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Contaminant exclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Retention and exclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Separating two liquids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Circumferential and rotational speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Pressure differentials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Limited space. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Installation restrictions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26Counterface design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Axial movement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Seal materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29Cases and inserts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29Garter springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29SKF Bore Tite Coating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29Adhesives and bonding agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Sealing lip materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Wear resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Operating temperatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Chemical resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Storage and handling of seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Cleaning and maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

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Industrial shaft seals

Industrial shaft seals are used to seal the openingbetween a rotating and a stationary component,or between two components in relative motion.Primary seal functions include:

Retain the lubricantExclude contaminantsSeparate two different mediaSeal under pressure

To be effective, industrial shaft seals shouldoperate with a minimum of friction and wear,even under unfavourable operating conditions.In order to meet the requirements of a variety ofdifferent applications and operating conditions,

SKF industrial shaft seals for rotating machinecomponents are manufactured from many dif-ferent designs, materials and executions. Eachof these designs and material combinations hasspecific properties, making them suitable for aparticular application. The main groups of shaftseals and accessories are:

Radial shaft seals

Seals for general industrial applicationsSeals for heavy industrial applications

Cassette seals

Axial shaft seals

Track pin sealsMetal face sealsV-ring sealsAxial clamp seals

Wear sleeves

SKF SPEEDI-SLEEVEWear sleeves for heavy industrial applications

Availability

The SKF assortment of industrial shaft sealscomprises hundreds of different designs andmaterial combinations. The products shown in

this catalogue and listed in the product tablesare the more commonly used seal types andsizes.

Guidance values

Since several factors simultaneously affect thesealing system and seal performance, all statedvalues in graphs and tables in this publicationshould be considered as guidelines only and notas absolute values for practical applications.

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1

HMS5 HMSA10 HMS4 HMSA7 CRS1 CRSA1

Profile overview selectionRadial shaft seals

Seals for general industrial applications, elastomeric sealing lip(s)

CRSH1 CRSHA1 CRW1 CRWH1 CRWA1 CRWHA1

CRW5 CRWA5 HDW1 HM14 TL7 X15

SL SLA SLX SLS DL DLA

YSLE YNSLE YSL

Seals for general industrial applications, PTFE sealing lip(s)

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HSF1

HSF2 HSF3 HSF4 HSF5 HSF6 HSF7

HSF8 HSF9

Product data general

HDSA2 HDSB1 HDSB2 HDSC1 HDSC2 HDSE1

HDSE2 HDSD1 HDSD2 SBF HDS4 HDS6

HS4 HS5 HS6 HS7 HS8

HDSA1HDS7 HDL HDLA HDS1 HDS2

Seals for heavy industrial applications

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1

MUD1 MUD2 MUD3 MUD4 MUD5 MUD6

Wear sleeves

MUD7

Cassette seals, SKF Mudblock

SKF SPEEDI-SLEEVE LDSLV3 LDSLV4

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HDDF

VR1/VA VR2/VS VR3/VL VR5/VRM VR6/VRME

MVR1

V-ring seals

CT1 CT4

Axial clamp seals

MVR2

Metal face seals

TP TPM

Axial shaft seals

Track pin seals, SKF Trackstar

VR4/VE

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1

Selection of seal design andmaterialSelecting an appropriate seal design and materialdepends on the operating conditions of the

application such as:

temperaturespeedpressure differentialtype of lubricantvertical or horizontal orientationrunout and shaft-to-bore misalignment

Because the influence of one operating con-dition typically dominates the seal selection

process, there are no universal rules for deter-mining the appropriate seal type or design fora given application. This section describes howoperating conditions affect seal performance andservice life and provides guidance on selectingthe most appropriate seal for a given application.

Matrix 1 and 2 on pages 90 to 91 and 194 to197 list the standard SKF radial shaft seals andtheir main features and permissible operatingconditions.

Grease retention

Greases have a relatively high viscosity and arerelatively easy to retain in a bearing arrange-ment. In many grease lubricated applications, anon-spring-loaded sealing lip design or a V-ringcan adequately retain the grease ( fig. 1).

However, more demanding applications mayrequire HMS5 or CRW1 spring-loaded radialshaft seals ( figs. 2 and 3).

When frequent relubrication is required, the

lip of at least one of the seals in the sealingarrangement should be directed toward the airside so that excess grease can escape via thesealing lip ( fig. 3). This avoids grease build-up,which can retain heat and limit heat dissipation.For grease lubricated applications, SKF recom-mends calculating the permissible circumferentialspeed for oil and halving the result.

Fig. 1

V-ring

Fig. 2

HMS5 seal

Fig. 3

CRW1 seal

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Oil retention

Lubricating oils, particularly relatively low-viscosity oils, are much more difficult to retainthan greases. Therefore, HMS5 or CRW1spring-loaded radial shaft seals ( figs. 4 and 5)

are recommended in order to achieve the neces-sary radial load and resistance to dynamic runoutand shaft-to-bore misalignment for a satisfactorysealing performance.

Standard HMS5 seals have a straight lip whileCRW1 seals are designed with SKF WAVE lips toprovide improved pumping ability, regardlessof the direction of shaft rotation ( fig. 6 onpage 57). Another way of increasing a sealspumping ability is to add a helix pattern, i.e.hydrodynamic features, to the sealing lip design.

The rubber outside diameter, like the onefound on HMS5 seals, helps compensate forsmall imperfections in the housing bore surfaceand is therefore recommended when the re-quired housing bore surface is questionable.

For very tough operating conditions, wherecircumferential speeds are relatively low, metalface seals, like the HDDF seal ( fig. 6), can beused for both oil or grease retention.

V-rings ( fig. 7) may also be used to retainoil, provided they are installed on the oil side

and supported axially on the shaft.

Fig. 4

HMS5 seal

Fig. 5

CRW1 seal

Fig. 6

HDDF metal face seal

Fig. 7

V-ring


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Contaminant exclusion

Radial shaft seals that are primarily used forcontaminant exclusion should be installed withthe lip pointing outward. When additional pro-tection is needed, SKF recommends a seal design

that incorporates an auxiliary lip, for example theHMSA10 or CRWA1 seals.For tough operating conditions, SKF WAVE

seals ( fig. 8) with hydrodynamic features arerecommended. To further enhance sealing ef-ficiency, two single-lip seals can be arranged intandem ( fig. 9) or a double-lip seal, like theHDSE1 seal, can be used ( fig. 10).

V-rings ( fig. 11) are used primarily to ex-clude contaminants. These seals, which act asflingers, rotate with the shaft and seal against

a surface that is perpendicular to the shaft.V-rings and axial clamp seals are often usedas secondary seals to protect the primary sealsfrom coarse contaminants.

None of these seal arrangements are intendedfor oil retention.

Fig. 8

CRW1 seal

Fig. 9

CRW1 seals in tandem

Fig. 10

HDSE1 seal

Fig. 11

V-ring

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Retention and exclusion

In many applications, the exclusion of contami-nants is just as important as lubricant retention.Seals with an auxiliary lip, like the HMSA10seals ( fig. 12), are appropriate for these

applications.Another option is to use two seals installed inopposite directions ( figs. 13 and 14) or twoopposing V-rings ( fig. 15) with a spacingwasher.

Under extremely tough operating conditions,SKF recommends using HDDF metal face seals( fig. 6 on page 18), provided that the slidingvelocity of the mating surfaces lies within thepermissible range.

Fig. 12

HMSA10 seal

Fig. 13

Two seals in opposite direction

Fig. 14

Two seals in opposite direction

Fig. 15

V-ring


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1

Separating two liquids

When an application has to keep two liquidsfrom coming into contact with each other, thereare two suitable solutions. These solutions,which depend on the availability of space and

required efficiency, include:

the use of two separate seals ( figs. 16 and17), positioned with their lips facing in oppositedirectionsthe use of HDSD1 double-lip seals ( fig. 18)

In both alternatives, the sealing lips must bespring-loaded. When using an HDSD seal, it isvery important to provide a means to lubricatethe sealing lips, i.e. the cavity between the seal-

ing lips must be filled with grease prior to instal-lation or during operation via lubrication holesdrilled through the metal case into the cavity.

Fig. 16

CRW1 seals

Fig. 17

HMS5 seals

Fig. 18

HDSD1 seal

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Circumferential and rotational speed

The permissible speed of a seal is determined byits design and sealing lip material as well as thematerial and condition of the shaft. All of thesefactors influence the heat generation at the seal

counterface. Lubrication of the sealing lip andthe characteristics of the lubricant also have adirect influence on heat generation becausethey have a direct impact on heat dissipation.

Diagram 1 compares the permissible circum-ferential speeds for various seal designs assum-ing normal seal operation, grease or oil retentionand no pressure differential across the seal.

Diagram 1

1) Support ring by customer


Circumferential speed [m/s (ft/min)]

0 5 15

HDDF

CRS1

HMS5

CRW1

HDS2

HS5

HS8

VR1

CT1

10 20

solid

split

1)

(3 937)

(984)

(1 969)

(2 953)

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1

Pressure differentials

When subjected to a pressure differential, theseal must resist the additional radial load gener-ated by the pressure. If the seal is not designedto resist the pressure, it will be forced against

the shaft, increasing the radial load, underliptemperature, friction and wear of the seal andthe counterface, resulting in shortened servicelife.

Standard seals are rated for no more than0,07 MPa at 5 m/s (10 psi at 1 000 ft/min), butSKF offers CRW5 and CRWA5 pressure profileseals that can accommodate 0,34 MPa at 5 m/s(50 psi at 1 000 ft/min). Beyond 0,34 MPa(50 psi), SKF offers a line of special order PTFEseals that can accommodate more than 3,5 MPa

(500 psi).In applications with pressure differentials,shaft seals should be secured axially from thelow-pressure side to prevent them from movingaxially. This can be accomplished by installingthe seal into a counterbore ( fig. 19) or byusing a retaining ring.

Fig. 19

CRWA5 seal

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Limited space

In many cases, the available space is insufficientfor a radial shaft seal having dimensions inaccordance with ISO 6194-1 or DIN 3670. Inthese situations, special radial shaft seal designs

must be used ( fig. 20).V-rings ( fig. 21) are also suitable forapplications with limited space because theycan be positioned outside the actual seal pos-ition. V-rings seal axially by exerting light pres-sure against the counterface that can be astationary or rotating machine component.

In applications with large shaft diameters,HS8 seals are an appropriate choice when spaceis limited ( fig. 22).

Fig. 20

Special seal design

Fig. 21

V-ring seal

Fig. 22

HS8 seal


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Installation restrictions

In applications where the seal cannot be installedvia the shaft end, a V-ring or any of the split HSFor HS designs can be used ( pages 204 to206).

After being positioned on the shaft, HS andHSF seals are held together by a spring andspring connector. These seals should be retainedaxially in the housing bore by a one-piece or splitcover plate.

Split HS radial shaft seals are suitable for cir-cumferential speeds up to 7,5 or 10 m/s(1 480 or 1 970 ft/min), depending on theirdesign, and are available for shaft diameters upto approximately 4 570 mm (180 in.).

Since V-rings are elastic, they can be

stretched and are therefore easy to install, evenin applications where they have to be passedover other components ( fig. 23). However,in the event that replacing a V-ring would requirethe time consuming removal of several compo-nents, it is advantageous to install one or tworeplacement V-rings on the shaft from the outset( fig. 24). When the time comes to replace aworn V-ring, it can be cut and removed and thereplacement V-ring can be pushed into position.

Fig. 23

V-ring seal

Fig. 24

V-ring seals

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Arrangement

Seals installed on vertical shafts are usuallymore exposed to contaminants like rain waterthan seals on horizontal shafts. Oil retention isalso more challenging for seals installed on ver-

tical shafts. In general, however, all seals listedin the product tables are suitable for use on bothhorizontal and vertical shafts.

V-rings ( figs. 25 and 26) have an interfer-ence fit on the shaft and rotate with it. They actas flingers and are therefore particularly suit-able as both primary and secondary seals onvertical shafts. Highly efficient sealing arrange-ments, like those found in submersible pumps,can be achieved using radial shaft seals in tan-dem with a V-ring for additional protection

against contaminants ( fig. 27).At relatively low speeds, HDDF metal faceseals ( fig. 28) effectively retain grease or oiland prevent the ingress of contaminants onvertical shafts.

Fig. 25

V-ring seal

Fig. 26

V-ring seal

Fig. 27

CRW5 seals + V-ring seal

Fig. 28

HDDF metal face seal


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Counterface design

The service life and performance of a seal arelargely influenced by:

shaft material and hardness

shaft surface finish and tolerance grade

dynamic runout and shaft-to-boremisalignment

A shaft surface that is too smooth can lead tolubricant starvation, while a shaft surface thatis too rough can accelerate sealing lip wear. Theshaft surface should be machined withoutdirectionality as directionality can cause leakagedepending on the direction of rotation. Dynamicrunout and shaft-to-bore misalignment cause

an uneven radial load on the circumference ofthe sealing lip. As a result, the sealing lip, par-ticularly at high speeds, will not be able to followthe shaft. This, in turn, will result in a gapbetween the sealing lip and the shaft, causingreduced sealing ability.

Unlike radial shaft seals, V-rings and axialclamp seals are not affected by normal coaxialitydeviations or runout.

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Axial movement

Axial movement of the shaft relative to thehousing bore does not detract from the sealingability of radial shaft seals ( fig. 29), providedthat the total surface in contact with the lip has

the same quality with respect to hardness andsurface finish.The amount of axial movement that can be

accommodated by V-rings, axial clamp seals andHDDF seals is limited by the permissible displace-ment of the seal relative to its counterface.

0

0

0

0

Fig. 29

Axial movement

Radial shaft seals

V-ring seals

Axial clamp seals

Metal face seal


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Seal materialsCases and inserts

Metal cases and reinforcements for SKF radialshaft seals are manufactured standard from

deep-drawn carbon sheet steel. The exposedsurfaces are treated to protect them from corro-sion during normal handling and storage.

SKF radial shaft seals that will be used in cor-rosive environments can also be designed witha stainless steel case on request.

Garter springs

The garter springs on SKF radial shaft seals aremanufactured standard from cold-drawn steel

wire. Exceptions are the metal-cased HDS seals,the all-rubber HS seals and the HMS5/HMSA10seals made from fluoro rubber that are designedwith stainless steel garter springs.

SKF Bore Tite Coating

SKF Bore Tite Coating is a water-based acrylicsealant available on most SKF metal-casedseals. The sealant is used as a coating on theoutside diameter of the seal. SKF Bore Tite

Coating is pliable with a thickness of 0,03 to0,07 mm (0.0012 to 0.0028 in.) to compensatefor small imperfections in the housing boresurface. The general guideline in Rubber Manu-facturers Association (RMA) is, that if the boresurface texture is greater than 2,5 m (100 in.)Ra, a sealant should be used. This sealant can beused at temperatures up to 200 C (390 F) andis compatible with most oils, greases, aqueousacids and alkalis, alcohols and glycols. Pleasenote that SKF Bore Tite Coating is not compatible

with aromatics, ketones or esters. Contact withthese substances will, however, have little or noeffect if wiped off quickly.

Adhesives and bonding agents

Adhesives and bonding agents are used toachieve static sealing ability and satisfactorybonding between metal and elastomers in sealdesigns. Both of them can be solvent or waterbased depending on the metal and elastomer to

be bonded.

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Sealing lip materials

In addition to its design, the material of a sealinglip can have a significant impact on sealing per-formance and reliability. SKF, therefore, manu-factures seals using a variety of sealing lip ma-

terials to meet the needs of different applications.The sealing lips of SKF seals are generallymade of elastomer materials. However, thermo-plastics like polytetrafluoroethylene (PTFE) aregaining in importance. PTFE is mainly used forspecial seals intended for particular applicationswhere improved thermal or chemical resistanceis demanded.

SKF industrial shaft seals are generally manu-factured from the materials listed in table 1.These materials have characteristics that make

them particularly suitable for specific applications.By changing the actual formulation and blend-ing, it is possible to modify the characteristics ofthe elastomers relative to:

resistance to swellingelasticitychemical resistancethermal resistancebehaviour in the coldgas permeability

Details about the chemical resistance of sealinglip materials to various media encountered inoperation are provided in the section Chemicalresistance, page 35.

A code is used to identify the sealing lip ma-

terial of SKF seals (table 1). The code alsoappears in the designations of metric radialshaft seals. For seals manufactured from acombination of materials, a combination of codeletters is used, like RD (nitrile rubber and SKFDuralip).

Table 1

SKF sealing lip materials

Composition of basic material Designation according toSKF IS0 1629 ASTM1) D1418

IS0 1043-1 ASTM D1600DIN 7728 Part 1

Acrylonitrile-butadiene rubber (nitrile rubber) R, RG NBR NBR

Hydrogenated acrylonitrile-butadiene rubber(SKF Duratemp) H HNBR HNBR

Carboxylated nitrile rubber (SKF Duralip) D XNBR XNBR

Polyacrylate elastomer P ACM ACM

Silicone rubber S MVQ VMQ

Fluoro rubber (SKF Duralife2)) V FPM FKM

Polytetrafluoroethylene T PTFE PTFE

1) American Society for Testing and Materials2) Previously named LongLife


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1

Nitrile rubber (R)

The term nitrile rubber is used in this publi-cation for acrylonitrile-butadiene rubber (NBR).This material has very good engineering prop-erties and is a general-purpose sealing lip ma-

terial. It is a copolymer manufactured fromacrylonitrile and butadiene that provides goodresistance to the following media:

Most mineral oils and greases with a mineraloil baseNormal fuels like gasoline, diesel and lightheating oilsAnimal and vegetable oils and fats and hotwater

Nitrile rubber also tolerates short-term dryrunning of the sealing lip. The permissible oper-ating temperature range of nitrile rubber is 40to +100 C (40 to +210 F). For brief periods,temperatures of up to 120 C (250 F) can betolerated.

SKF also offers a special nitrile rubber com-pound with a temperature range between 55and +110 C (65 and +230 F).

SKF Duralip (D)

SKF Duralip is a carboxylated nitrile rubber(XNBR) developed by SKF that combines thegood technical properties of nitrile rubber withan increased resistance to wear ( diagram 2on page 33). It is mainly used for seals for heavyindustrial applications. Seals made of this ma-terial should be chosen when abrasive contam-inants like sand, soil and scale could reach theseal counterface on the shaft.

SKF Duratemp (H)

SKF Duratemp is a hydrogenated nitrile rubber(HNBR) developed by SKF that combines thewear resistance of SKF Duralip with increasedhigh-temperature resistance ( diagram 3 on

page 34). SKF Duratemp is also more resistantto chemical attack, weather, ageing and ozone.However, mixtures of oil in air may have a nega-tive effect. The upper operating temperaturelimit is 150 C (300 F), which is significantlyhigher than that of ordinary nitrile rubber. SKFDuratemp is mainly used for seals for heavy in-dustrial applications or where extended servicelife is required.

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SKF Duralife1) (V)

The fluoro rubber (FKM) compound, SKF Duralife,has been developed by SKF and is characterizedby its very good wear, thermal and chemicalresistance. Its resistance to weather and ageing

from UV light and ozone is also very good and itsgas permeability is very slight.SKF Duralife has exceptional properties even

under harsh environmental conditions and canwithstand operating temperatures ranging from20 to +200 C (5 to +390 F). In applicationswith low dynamic runout, the temperaturerange can be extended down to 40 C (40 F).SKF also offers special low-temperature fluororubber compounds on request.

SKF Duralife is also resistant to oils and hy-

draulic fluids, fuels and lubricants, mineral acidsand aliphatics as well as aromatic hydrocarbonsthat would cause many other seal materials tofail. Seals made of SKF Duralife can also toleratedry running of the lip for short periods. Theseals should not be used in the presence of es-ters, ethers, ketones, certain amines and hotanhydrous hydrofluorides. Because of the com-pounds valuable properties, SKF manufacturesseals with sealing lips made of SKF Duralife forall common shaft diameters.

Polytetrafluoroethylene (PTFE)

PTFE is a thermoplastic polymer that is compat-ible with a wide assortment of lubricants andfeatures chemical resistance that is far superiorto that of any other sealing lip material. PTFEhas a smooth, dirt-resistant surface. Seals withPTFE lips can accommodate high surface speedswhile offering extended service life. The sealscan tolerate dry running and are particularlyvaluable in highly contaminated applications

because of their excellent exclusion ability. PTFEis used for auxiliary seal elements or for primarysealing lips for special applications. For optimumperformance, PTFE seal elements require ahigh-quality seal counterface and extra careduring installation. The normal operatingtemperature range extends from 70 to +200 C(90 to +390 F), but may go up to 250 C(480 F).

WARNING:At temperatures above 300 C (570 F),all fluoro elastomers and PTFE compoundsgive off dangerous fumes. This can occur,for example, if a welding torch is used whenremoving a bearing. Although the fumesare only produced at such high tempera-tures, once heated, the seals will be dan-gerous to handle even when they havecooled down. If it is necessary to handlePTFE or fluoro elastomer seals that havebeen subjected to the high temperaturesmentioned above, the following safetyprecautions should be observed:

Protective goggles and gloves shouldalways be worn.The remains of seals should be put inan airtight plastic container markedMaterial will etch.Comply with the safety precautionsincluded in the material safety data thatcan be provided upon request.

If there is contact with your skin, thisshould be washed with soap and plentyof water. Wash your eyes with plenty ofwater if these materials get into your eyes.A doctor should always be consulted. Thisalso applies if the fumes have been inhaled.


1) Previously named LongLife

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1

Wear resistance

The wear resistance of a seal depends largely onthe sealing lip material, as well as on the shaftsurface finish, type of lubricant, circumferential

speed, temperature and pressure differentials.A comparison of wear resistance for varioussealing lip materials used by SKF is provided indiagram 2. It is valid for seals of the same size,operating under identical conditions.

Diagram 2

Wear resistance

Siliconerubber

Polyacrylateelastomer

Nitrile rubber

Carboxylated nitrile rubber (SKF Duralip)

Hydrogenated nitrile rubber (SKF Duratemp)

Fluoro rubber (SKF Duralife)

Polytetrafluoroethylene

Polyacrylate elastomer

Polyacrylate elastomers are more heat resistantthan nitrile rubber or SKF Duralip. The operatingtemperature range for polyacrylate elastomerslies between 40 and +150 C (40 and +300 F)

and in some fluids the upper limit may be ex-tended to 175 C (345 F). Seals of polyacrylateare resistant to ageing and ozone and are alsosuitable for use with lubricants containing EPadditives. They should not be used to seal water,acids or alkalis etc. Dry running should beavoided.

Silicone rubber

Silicone rubber is characterized by high thermalresistance and can withstand temperatures

ranging from 70 to +160 C (90 to +320 F).Silicone rubber absorbs lubricants, thereby min-imizing friction and wear. SKF silicone rubberseals are particularly suitable for applicationswith very low or very high temperatures and forlow-friction sealing of bearing arrangements.They are not very resistant to oxidized oils orcertain EP additives and should be protectedagainst abrasive substances. Sealing lips madeof silicone rubber should not be exposed to dryrunning.

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Operating temperatures

Both low and high temperatures influence thesealing performance. At low temperatures, thesealing lip loses its elasticity and becomes hard

and brittle. Sealing efficiency decreases and theseal becomes more susceptible to mechanicaldamage.

For applications where temperatures are con-tinuously high, special high-temperature lipmaterials should be used, for example, PTFE orthe SKF fluoro rubber material, SKF Duralife.

Friction, circumferential speed, viscosity ofthe medium being sealed as well as the specificheat transfer along the shaft influence the tem-perature at the sealing position and the tem-

perature between the lip and lubricant film onthe counterface. High temperatures generallylead to a breakdown of the lubricant film, result-ing in insufficient lubrication, one of the mostcommon causes of premature seal failure.

The static sealing ability between the outsidediameter of the seal and the housing bore may

also be affected if these components are madeof different materials with significantly differentcoefficients of expansion and shrinkage.

Refer to diagram 3 to view the permissibleoperating temperature ranges of sealing lip

materials normally used by SKF.

Diagram 3

Permissible operating temperatures


Temperature [C (F)]

0 +50 +100 +150 +200 +25020406080

(+32) (+122) (+212) (+302) (+392) (+482)(4)(40)(76)(112)

Nitrile rubber

SKF Duralip

SKF Duratemp

Polyacrylate elastomer

Silicone rubber

SKF Duralife

Polytetrafluoroethylene

34


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1

Chemical resistance

In table 2, Chemical resistance ( pages 36to 43), information is provided regarding the re-sistance of SKF sealing lip materials to most of

the substances encountered in industrial appli-cations. The information is based on in-housetesting and the experience of users, as well asinformation from the suppliers of the variousmaterials. Unless otherwise stated, the infor-mation is valid for media of commercial purityand quality.

The chemical resistance of a seal is influencedby temperature, pressure and the amount ofmedia present. Other important factors to con-sider when selecting a suitable sealing lip material

include:

type of service (static or dynamic)circumferential speed of the sealing lipshaft and housing materialssurface finish of the seal counterface

Because the above mentioned factors alsoinfluence the service life and performance ofthe seal, the information contained in the tableChemical resistance can only be considered as

a rough guide.

Explanation for table 2 ( pages 36to 43), Chemical resistanceRT = room temperature (20 C (70 F))1 = minor effect2 = moderate effect3 = static only4 = not recommended5 = insufficient data, test before use

35


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Table 2

Chemical resistance

Medium Temperature Mediums effect on sealing lip material

R, D, H V P S

C (F)

AAcetaldehycle RT 4 4 4 2Acetamide RT 1 2 4 2Acetic acid, 100% (glacial) 60 (140) 3 3 4 2Acetic acid, 30% RT 2 2 4 1Acetic acid, 3% (vinegar) RT 2 1 4 1Acetic anhydride RT / 80 (175) 3 4 4 3Acetone RT 4 4 4 3Acetophenone RT 4 4 4 4Acetylene 60 (140) 1 1 5 2Acrylonitrile RT / 60 (140) 4 3 4 4Adipic acid (aq) RT 1 1 5 5Alum (aq) 100 (210) 1 1 4 1

Aluminium acetate (aq) RT 2 4 4 4Aluminium chloride (aq) RT 1 1 1 2Aluminium fluoride (aq) RT 1 1 5 2Aluminium nitrate (aq) RT 1 1 5 2Aluminium phosphate (aq) RT 1 1 5 1Aluminium sulphate (aq) RT / 60 (140) 1 1 4 1Ammonia (anhydrous) RT 2 4 4 3Ammonia gas RT 1 4 4 2Ammonia gas 80 (175)/ 100 (210) 4 4 4 1Ammonium carbonate (aq) RT / 60 (140) 2 5 4 5Ammonium chloride (aq) RT / 60 (140) 1 1 5 5Ammonium chloride (dry) (sal ammoniac) RT 1 1 1 2Ammonium nitrate (aq) RT 1 5 2 5Ammonium persulphate (aq) RT 4 5 4 5Ammonium phosphate (aq) RT / 60 (140) 1 5 5 1Ammonium sulphate (aq) 100 (210) 1 4 4 5Amyl acetate RT 4 4 4 4Amyl alcohol 60 (140) 2 2 4 4Aniline 60 (140) / 100 (210) 4 3 4 4Aniline dyes RT 4 2 4 3Aniline hydrochloride RT 2 2 4 4Aniline hydrochloride 100 (210) 4 5 5 5Animal fats 80 (175) 1 1 1 2Aqua Regia RT 4 5 4 4Arsenic acid RT / 60 (140) 1 1 3 1Arsenic trichloride (aq) RT 1 5 5 5Asphalt (liquid) 100 (210) 2 2 4 4

BBarium chloride (aq) RT / 60 (140) 1 1 1 1Barium hydroxide (aq) RT / 60 (140) 1 1 4 1Barium sulphate RT / 60 (140) 1 1 4 1Barium sulphide (aq) RT / 60 (140) 1 1 4 1

Beer RT 1 1 4 1Benzaldehyde RT / 60 (140) 4 4 4 4Benzene RT 4 1 4 4Benzene sulphonic acid RT 4 1 4 4Benzoic acid RT / 60 (140) 4 1 4 4Benzoyl chloride RT 4 1 4 5Benzyl alcohol RT / 60 (140) 4 1 1 2Benzyl benzoate 50 (120) / 60 (140) 4 1 4 5Benzyl chloride RT 4 1 4 4Blast furnace gas 100 (210) 4 1 4 1Borax (aq) RT / 60 (140) 2 1 5 2Bordeaux mixture RT 2 1 4 2Boric acid 60 (140) / 100 (210) 1 1 4 1Brake fluid, ATE 80 (175) 4 4 4 1Brake fluid, glycol ether 80 (175) 4 5 4 1Brine (sodium chloride, aq) RT / 50 (120) 1 1 4 1

Bromine, anhydrous (liquid/gaseous) RT 4 1 4 4Bromine trifluoride RT 4 4 4 4Bromine water RT 4 1 4 4Bromobenzene RT 4 1 4 4


36


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1

cont. table 2

Chemical resistance

Medium Temperature Mediums effect on sealing lip materialR, D, H V P S

C (F)

Bunker oil 60 (140) 1 1 1 2Butadiene (gaseous or liquified) RT 4 1 4 4Butane (gaseous or liquified) RT 1 1 1 4Butter (animal fat) RT / 80 (175) 1 1 1 2Butyl acetate RT 4 4 4 4Butyl acrylate RT 4 4 4 5Butyl alcohol RT 2 1 4 2Butyl amines RT 3 4 4 4Butylene RT 2 1 4 4Butyl stearate 50 (120) 2 1 5 5Butyraldehyde RT 4 4 4 4

C

Calcium acetate (aq) RT 2 4 4 4Calcium bisulphite (aq) RT 1 1 4 1Calcium chloride (aq) 60 (140) 1 1 1 1Calcium hydroxide (aq) RT 1 1 4 1Calcium hypochlorite (aq) RT / 60 (140) 2 1 4 2Calcium nitrate (aq) RT / 40 (105) 1 1 1 2Cane sugar liquors RT / 60 (140) 1 1 4 1Carbon dioxide RT 1 1 5 2Carbon disulphide RT 3 1 3 4Carbonic acid RT 2 1 1 1Carbon monoxide 60 (140) 1 1 5 1Carbon tetrachloride RT / 60 (140) 3 1 4 4Castor oil RT 1 1 1 1Cellosolve (ethyl glycol) RT 4 3 4 4Cellosolve acetate (ethyl glycol acetate) RT 4 4 4 4Chlorine (dry) RT 4 1 4 4Chlorine (wet) RT 4 1 4 4Chlorine dioxide RT 4 1 4 5Chlorine trifluoride RT 4 4 4 4Chloroacetic acid 60 (140) 4 4 4 5Chloroacetone RT 4 4 4 4Chlorobenzene RT 4 1 4 4Chlorobromomethane RT 4 1 4 4Chlorobutadiene RT 4 1 4 4Chloroform RT 4 1 4 4Chlorosulphonic acid RT 4 4 4 4Chlorotoluene RT 4 1 4 4Chromic acid 60 (140) 4 1 4 3Citric acid 60 (140) / 70 (160) 1 1 5 1Cobalt chloride (aq) RT 1 1 4 2Coconut oil 50 (120) / 80 (175) 1 1 1 1Cod liver oil RT 1 1 1 2Coke oven gas 80 (175) 4 1 4 2

Copper acetate (aq) RT 2 4 4 4Copper chloride (aq) RT 1 1 1 1Copper sulphate (aq) 60 (140) 1 1 4 1Corn oil RT / 60 (140) 1 1 1 1Cottonseed oil RT / 70 (160) 1 1 1 1Cresol 50 (120) / 70 (160) 4 1 4 4Cumene (isopropylbenzene) RT 4 1 4 4Cyclohexane RT 1 1 1 4Cyciohexanol RT 3 1 5 4Cyclohexanone RT 4 4 4 4p-Cymene RT 4 1 4 4

DDecahydronaphthalene (decalin) RT / 60 (140) 4 1 5 4Detergent RT 1 1 4 1Developing fluids (photography) RT 1 1 5 1

Diacetone alcohol RT 4 4 4 2Dibenzyl ether RT 4 4 5 5Dibutyl amine RT 4 4 4 3Dibutyl ether RT 4 3 3 4

37


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cont. table 2

Chemical resistance


C (F)

Dibutyl phthalate RT / 60 (140) 4 3 4 2Dibutyl sebacate RT / 60 (140) 4 2 4 2o-Dichlorobenzene RT 4 1 4 4Dicyclohexylamine RT 3 4 4 5Diethyl amine RT 2 4 4 2Diethyl benzene RT 4 1 5 4Diethyl ether RT 4 4 3 4Diethyl sebacate RT 2 2 4 2Diisopropyl benzene RT 4 1 5 5Dimethyl aniline (Xylidine) RT 3 4 4 4Dimethyl ether RT 1 2 4 1Dimethyl formamide RT / 60 (140) 2 4 4 2Dimethyl phthalate RT 4 2 4 5

Dioctyl phthalate RT / 60 (140) 3 2 4 3Dioctyl sebacate RT / 60 (140) 4 2 4 3Dioxane RT / 60 (140) 4 4 4 4Dioxolane RT 4 4 4 4Dipentene RT 2 1 4 4Diphenyl oxide RT 4 1 4 3Dowtherm oils 100 (210) 4 1 4 3Dry cleaning fluids 40 (105) 3 1 4 4

EEpichlorohydrin RT 4 4 4 4Ethane RT 1 1 1 4Ethanol (denatured alcohol) RT 1 1 4 1Ethanolamine (monoethanolamine) RT 2 4 4 2Ethanolamine (di- and triethanolamine) 50 (120) 5 4 4 2Ethyl acetate RT 4 4 4 2Ethyl acrylate RT 4 4 4 2Ethyl benzene RT 4 1 4 4Ethyl benzoate RT 4 1 4 4Ethyl chloride RT 1 1 4 4Ethylene RT 1 1 5 5Ethylene chloride RT 4 2 4 4Ethylene chlorohydrin RT 4 1 4 3Ethylene diamine RT 1 4 4 1Ethylene glycol RT 1 1 2 1/2Ethylene glycol 100 (210) 1 1 3 1/2Ethylene oxide RT 4 4 4 4Ethylene trichloride RT 4 1 4 4Ethyl ether RT 3 4 4 4Ethyl formate RT 4 1 5 5Ethyl glycol (Cellosolve) RT 4 3 4 4Ethyl glycol acetate (Cellosolve acetate) RT 4 4 4 4Ethyl silicate RT 1 1 5 5

FFatty acids 100 (210) 2 1 5 3Ferric chloride (aq) RT 1 1 1 2Ferric nitrate (aq) RT 1 1 1 3Ferric sulphate (aq) RT 1 1 1 2Fish oil RT 1 1 5 1Fluorine (liquified) RT 4 2 4 4Fluorobenzene RT 4 1 4 4Fluorosilic acid 60 (140) 1 1 5 4Formaldehyde RT 3 1 4 2Formaldehyde, 37% below 100 (210) 2 1 4 2Formic acid RT / 60 (140) 2 3 5 2

Fuels Aero engine fuels JP:

JP3 (MIL-J-5624 G) RT 1 1 2 4 JP4 (MIL-J-5624 G) RT 1 1 2 4 JP5 (MIL-J-5624 G) RT 1 1 2 4 JP6 (MIL-F-25656 B) RT / 60 (140) 1 1 5 4


38


41/483

1

cont. table 2

Chemical resistance


C (F)

ASTM reference fuels: ASTM-A (MIL-S-3136 B Typ 1) RT / 60 (140) 1 1 2 4 ASTM-B (MIL-S-3136 B Typ 111) RT / 60 (140) 1 1 5 4 ASTM-C RT / 60 (140) 2 1 4 4

Diesel fuel 60 (140) 1 1 2 2 Fuel oil 60 (140) 1 1 1 4 Gasohol (10% ethanol or methanol) RT 2 3 4 4 Kerosene RT 1 1 1 4 Mineral oil 100 (210) 1 1 1 2 Petrol RT 1 1 4 4Fumaric acid RT 1 1 4 2Furan RT 4 5 4 5Furfural RT 4 4 4 4

Furfuran RT 4 5 4 5GGelatine (aq) 40 (105) 1 1 4 1Glucose RT 1 1 5 1Glue RT 1 1 5 1Glycerin 100 (210) 1 1 3 1Glycols 100 (210) 1 1 4 1/2

Hn-Hexaldehyde RT 4 4 5 2Hexane RT / 60 (140) 1 1 1 41-Hexene RT 2 1 1 4Hexyl alcohol RT 1 1 4 2Hydraulic fluids Hydraulic oils (acc. to DIN 51524) 80 (175) 1 1 1 3 Hydraulic fluids (acc to DIN 51502):

HFA (oil in water emulsion) 55 (130) 1 1 5 5 HFB (water in oil emulsion) 60 (140) 1 1 5 5 HFC (aqueous Polymer solutions) 60 (140) 1 1 5 1 HFD (phosphoric esters) 80 (175) 4 2/4 4 4 Skydrol 500 80 (175) 4 4 4 3 Skydrol 7000 80 (175) 4 2 4 3

Hydrazine RT 2 4 5 3Hydrobromic acid RT / 60 (140) 4 1 4 4Hydrochloric acid (conc.) RT 3 1 4 3Hydrochloric acid (conc.) 80 (175) 4 2 4 4Hydrocyanic acid (Prussic acid) RT 2 1 4 3Hydrofluoric acid (conc.) RT 4 1 4 4Hydrofluoric acid (conc.) 100 (210) 4 3 4 4Hydrofluoric acid (anhydrous) 100 (210) 4 4 4 4Hydrogen gas RT 1 1 2 3Hydrogen peroxide (90%) RT 4 2 4 2

Hydrogen sulphide (wet) RT / 100 (210) 4 4 4 3Hydroquinone RT 4 2 4 5Hypochlorous acid RT 4 1 4 5

IIodine pentafluoride RT 4 4 4 4Isobutyl alcohol RT 2 1 4 1Isooctane RT 1 1 1 4Isophorone RT 4 4 4 4Isopropyl acetate RT / 80 (175) 4 4 4 4Isopropyl alcohol RT / 60 (140) 2 1 4 1Isopropyl chloride RT 4 1 4 4Isopropyl ether RT / 60 (140) 2 4 3 4

LLactic acid RT 1 1 4 1

Lactic acid 100 (210) 4 1 4 2Lard 80 (175) 1 1 1 2Lavender oil RT 2 1 2 4Lead acetate (aq) RT / 60 (140) 2 2 4 4

39


42/483

cont. table 2

Chemical resistance


C (F)

Lead nitrate (aq) RT 1 5 5 2Linoleic acid RT 2 2 5 2Linseed oil RT / 60 (140) 1 1 1 1Lubricants ASTM oil No. 1 100 (210) 1 1 1 3 ASTM oil No. 2 100 (210) 1 1 1 3 ASTM oil No. 3 100 (210) 1 1 1 3 ATF oils, type A 100 (210) 1 1 1 4 ATF oils, type I 100 (210) 1 1 1 4 ATF oils, type II 100 (210) 1 1 1 4 ATF oils, type F 100 (210) 1 1 1 4 ATF oils, type Mercon 100 (210) 1 1 1 4 EP lubes 100 (210) 2 1 1 4

Fluorolube 100 (210) 1 2 5 1 Grease MIL-G-7118 A 80 (175) 1 1 3 3 Grease MIL-G-7711 A 80 (175) 1 1 1 3 Lubricating oils (petroleum) 100 (210) 1 1 1 4 Red oil (MIL-H-5606) 100 (210) 1 1 1 4 RJ-1 (MIL-F-25558 B) 100 (210) 1 1 1 4 RP-1 (MIL-F-25576 C) 100 (210) 1 1 1 4 Motor oil SAE 30 100 (210) 1 1 1 1 Transmission oil SAE 90 100 (210) 1 1 1 4 Transmission oil MIL-L-23699 A 100 (210) 1 1 3 3 Silicone greases 120 (250) 1 1 1 3 Silicone oils 120 (250) 1 1 1 3 Transformer oil (Pyranol) 60 (140) 4 1 5 4 Transformer oil 60 (140) 1 1 2 2 Transmission fluid type A RT 1 1 1 2 Turbine oil 100 (210) 2 1 1 4

MMagnesium chloride (aq) 100 (210) 1 1 5 1Magnesium hydroxide (aq) 100 (210) 2 1 4 5Magnesium sulphate (aq) 100 (210) 1 1 4 1Maleic acid 100 (210) 4 1 4 5Maleic anhydride 60 (140) 4 4 4 5Malic acid RT 1 1 4 2Mercury RT / 60 (140) 1 1 5 5Mercury chloride (aq) RT / 60 (140) 1 1 5 5Mesityl oxide RT 4 4 4 4Methane RT 1 2 1 4Methanol (methyl alcohol) 60 (140) 1 4 4 1Methyl acetate RT 4 4 4 4Methyl acrylate RT 4 4 4 4Methyl aniline RT 4 2 4 5Methyl bromide RT 2 1 3 5

Methyl cellosolve (methyl glycol) RT 3 4 4 4Methyl chloride RT 4 2 4 4Methyl cyclopentane RT 4 2 4 4Methylene chloride RT 4 2 4 4Methyl ethyl ketone RT 4 4 4 4Methyl formate RT 4 5 5 5Methyl glycol (Cellosolve) RT 3 4 4 4Methyl isobutyl ketone RT 4 4 4 4Methyl methacrylate RT 4 4 4 4Methyl salicylate RT 4 5 5 5Milk RT 1 1 4 1Mustard gas RT 5 5 5 1

NNaphtha RT 2 1 2 4Naphthalene 60 (140) 4 1 5 4

Naphthalenic acid RT 2 1 5 4Natural gas RT 1 1 2 1Neat-s-foot oil RT / 60 (140) 1 1 1 2Nickel acetate (aq) RT 2 4 4 4


40


43/483

1

cont. table 2

Chemical resistance


C (F)

Nickel chloride RT 1 1 4 1Nickel sulphate (aq) RT / 60 (140) 1 1 4 1Nitric acid (conc.) RT 4 3 4 4Nitric acid (fuming) RT 4 4 4 4Nitric acid (dilute) RT 4 1 4 2Nitrobenzene 50 (120) 4 2 4 4Nitroethane RT 4 4 4 4Nitrogen RT 1 1 1 1Nitrogen tetroxide RT 4 4 4 4Nitromethane RT 4 4 4 4

0Octadecane RT / 50 (120) 1 1 2 4

n-Octane RT 2 1 4 4Octyl alcohol RT 2 1 4 2Oleic acid 70 (160) 1 2 2 4Olive oil 60 (140) 1 1 1 3Oxalic acid 70 (160) 2 1 5 4Oxygen RT 2 1 2 1Oxygen > 100 (210) 4 2 4 2Ozone RT 4 1 2 1

PPalmitic acid 60 (140) 1 1 4 4Peanut oil RT / 50 (120) 1 1 1 1Perchloric acid RT 4 1 4 4Perchloroethylene RT / 60 (140) 2 1 4 4Petroleum below 120 (250) 1 1 2 2Petroleum above 120 (250) 4 2 4 4Petroleum ether RT / 60 (140) 1 1 1 4Petroleum gas (liquified) RT 1 1 3 3Phenol 60 (140) / 100 (210) 4 1 4 4Phenyl ethyl ether RT 4 4 4 4Phenyl hydrazine RT / 60 (140) 4 1 4 5Phoron (diisopropylidene acetone) 60 (140) 4 4 4 4Phosphoric acid, 20% 50 (120) / 60 (140) 2 1 5 2Phosphoric acid, 45% 50 (120) / 60 (140) 4 1 5 3Phosphorus trichloride RT 4 1 5 5Pickling solution RT 4 2 4 4Picric acid RT 4 1 5 4Pinene RT 2 1 4 4Pine oil RT 4 1 5 4Piperidine RT 4 4 4 4Potassium acetate (aq) RT 2 4 4 4Potassium chloride (aq) RT / 60 (140) 1 1 1 1Potassium cyanide (aq) RT / 50 (120) 1 1 1 1

Potassium dichromate (aq) RT 1 1 1 1Potassium hydroxide (aq) 60 (140) 2 4 4 4Potassium nitrate (aq) RT / 60 (140) 1 1 1 1Potassium sulfate (aq) RT / 60 (140) 1 1 4 1Propane RT 1 1 1 4Propyl acetate RT 4 4 4 4Propyl alcohol RT / 60 (140) 1 1 4 1Propylene RT 4 1 4 4Propylene oxide RT 4 4 4 4Prussic acid (hydrocyanic acid) RT 2 1 4 3Pyridine RT 4 4 4 4Pyroligneous acid RT 4 4 4 5Pyrrole RT 4 4 4 2

RRapeseed oil RT 2 1 2 4

Refrigerants (acc. to DIN 8962) R 11 RT 2 1 5 4 R 12 RT 1 2 1 4 R 13 RT 1 1 5 4

41


44/483

cont. table 2

Chemical resistance


C (F)

R 13 B1 RT 1 1 5 4 R 14 RT 1 1 5 4 R 21 RT 4 4 5 4 R 22 RT 4 4 2 4 R 31 RT 4 4 5 5 R 32 RT 1 4 5 5 R 112 RT 3 1 5 4 R 113 RT 1 2 5 4 R 114 RT 1 2 5 4 R 114 B2 RT 2 2 5 4 R 115 RT 1 2 5 5 R C 318 RT 1 2 5 5

SSalicylic acid RT 2 1 5 5Sea water RT 1 1 4 1Silver nitrate (aq) RT 2 1 1 1Soap solution RT 1 1 4 1Sodium acetate (aq) RT 2 4 4 4Sodium bicarbonate (aq) 60 (140) 1 1 5 1Sodium bisulphite (aq) 100 (210) 1 1 4 1Sodium carbonate (soda) RT / 60 (140) 1 1 5 1Sodium chloride (aq) RT / 100 (210) 1 1 5 1Sodium cyanide (aq) RT 1 1 5 1Sodium hydroxide (aq) RT 2 2 3 2Sodium hypochlorite (aq) RT / 50 (120) 2 1 4 5Sodium metaphosphate RT / 60 (140) 1 1 5 2Sodium nitrate (aq) RT / 60 (140) 2 5 5 4Sodium phosphate (aq) RT / 60 (140) 1 1 4 4Sodium silicate (aq) RT / 60 (140) 1 1 5 5Sodium sulphate (aq) (Glaubers salt) RT / 60 (140) 1 1 4 1Sodium thiosulphate (aq) RT / 50 (120) 2 1 4 1Soyabean oil RT 1 1 1 1Stannic chloride (aq) RT / 80 (175) 1 1 5 2Stannous chloride (aq) RT / 80 (175) 1 1 5 2Steam below 150 (300) 4 4 4 3Steam above 150 (300) 4 4 4 4Stearic acid 60 (140) 2 2 4 2Stoddard solvent RT 1 1 1 4Styrene RT 4 2 4 4Sucrose solution RT / 60 (140) 1 1 4 1Sulphur RT / 60 (140) 4 1 4 3Sulphur chloride (aq) RT 3 1 4 3Sulphur dioxide (dry) RT / 60 (140) 4 1 4 2Sulphur dioxide (liquified) RT / 60 (140) 4 1 4 2Sulphur dioxide (wet) RT / 60 (140) 4 1 4 2

Sulphur hexafluoride RT 2 1 4 2Sulphuric acid (conc.) RT / 50 (120) 4 1 4 4Sulphuric acid (20%) (battery acid) 60 (140) 4 1 4 4Sulphuric acid (dilute) RT 3 1 2 4Sulphurous acid RT / 60 (140) 4 1 4 4Sulphur trioxide RT 4 1 4 2

TTannic acid RT / 60 (140) 1 1 4 2Tar, bituminous RT 2 1 4 2Tartaric acid 60 (140) 1 1 5 1Tepineol RT 2 1 5 5Tetrabromoethane RT 4 1 4 4Tetrabromomethane RT 4 1 5 4Tetrabutyl titanate RT 2 1 5 5Tetrachloroethylene 60 (140) 4 2 4 4

Tetraethyl lead RT 2 1 5 5Tetrahydrofuran RT 4 4 4 4Tetrahydronaphthalene (Tetralin) RT 4 1 5 4Thionyl chloride RT 4 2 4 5


42


45/483

1

cont. table 2

Chemical resistance


C (F)

Titanium tetrachloride RT 2 1 4 4Toluene RT 4 1 4 4Toluene diisocyanate RT 4 4 4 4Triacetin RT 2 1 4 5Tributoxy ethyl phosphate RT 4 1 4 5Tributyl phosphate RT / 60 (140) 4 4 4 4Trichloroacetic acid 60 (140) 5 4 4 4Trichloroethane RT 4 1 4 4Trichloroethylene RT 4 1 4 4Tricresyl phosphate RT / 60 (140) 4 1 4 3Triethanol amine RT 2 4 4 5Triethyl aluminium RT 4 2 4 5Triethyl borane RT 4 1 4 5

Trinitrotoluene RT 4 2 4 5Trioctyl phosphate RT / 60 (140) 4 2 4 3Tung oil (China wood oil) RT 1 1 1 4Turpentine RT 1 1 2 4

VVarnish RT 2 1 4 4Vegetable oil 60 (140) 1 1 1 2Vinyl acetylene RT 1 1 5 2Vinyl chloride RT 4 1 5 5

WWater 100 (210) 1 1 4 1Whisky RT 1 1 4 1White oil RT / 80 (175) 1 1 1 4Wine RT 1 1 4 1Wood oil RT 1 1 1 4

XXylene RT 4 1 4 4Xylidine (di-methyl aniline) RT 3 4 4 4

ZZeolites RT 1 1 5 5Zinc acetate (aq) RT 1 1 4 4Zinc chloride (aq) RT 1 1 4 1Zinc sulphate (aq) RT 1 1 4 1

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Storage and handling of sealsGeneral

The following guidelines for the storage andcleaning of seals are valid for natural and syn-

thetic elastomer materials and are in accord-ance with ISO 2230 and DIN 7716 standards.The storage guidelines set forth in DIN 7716are valid for long-term storage.

Unfavourable storage conditions and improperhandling can change the physical properties ofmost products made from natural or syntheticrubber. This can result in hardening or soften-ing, permanent deformation, peeling or cracks,which can lead to a shortened service life orrender the products altogether useless. These

changes can be brought about by storing theproducts under stress or load or from the influ-ence of oxygen, ozone, heat, light, moisture orsolvents. When stored properly, elastomer prod-ucts generally retain their properties for severalyears.

Storage

The storage area should be cool, dry, moderatelyventilated and there should be as little dust as

possible. Outdoor storage without protectionshould be avoided.

The appropriate storage temperature dependson the elastomer. The most favourable storagetemperature for synthetic rubber seals is 15 to25 C (60 to 80 F).

Elastomer products that have been subjectedto low temperatures during transport or storagemay become stiff. They should therefore bewarmed and kept at a temperature of at least20 C (70 F) before being unpacked and used in

order to prevent exposure to condensation.In heated storage rooms, the products should

be shielded from the heat source. There shouldbe at least 1 m (3 ft.) between the packages andthe source of heat. In rooms where a heaterwith a fan is used, the distance should be greater.Storage in damp rooms should be avoided be-cause of the risk of condensation. A storage fa-cility with relative humidity below 65% isexcellent.

Seals should be protected from light, particu-

larly direct sunlight or artificial light with a highproportion of UV radiation. Any windows in thestore should therefore be covered with a red or

orange coating (never blue). Ordinary light bulbsare preferred for illumination.

Seals should be wrapped or stored in airtightcontainers, protecting them from atmosphericchanges and particularly against drafts.

Because ozone is particularly damaging,steps must be taken to make sure that no ozoneis produced in the storage facility as the result ofusing electric motors or other equipment thatcan produce sparks or other electric discharges.Combustion fumes and vapours that can pro-duce ozone as the result of photochemical pro-cesses should be exhausted. For this reason,solvents, fuels, lubricants, chemicals, acids, dis-infectants etc. should not be stored in the sameroom as the seals.

Elastomer products should not be subjectedto tension, compression or other forms of loadduring storage as this can produce permanentdeformations and cracks. Seals should thereforenot be hung on hooks during storage. Certainmetals, especially copper and manganese, dam-age elastomer products. Contact with thesemetals should therefore be avoided and theseals should be covered with layers of paper orpolyethylene to prevent such contact.

In case it is necessary to repack the seals,

packaging and covering materials should notcontain substances such as copper or alloyscontaining copper, petroleum, oil etc. that cancause damage to the seals. The packagingmaterials should not contain softeners.

If the products are powdered, suitable powdersare talcum, chalk, finely divided glimmer andrice starch.

Seals made of different materials should notbe in contact with each other. This is particularlyimportant when the seals are different in colour

as this will avoid discolouration.Seals should be stored for the shortest period

of time possible. Where long-term storage is in-volved, care should be taken that newly arrivedproducts are kept separate from those alreadyin storage to enable use of seals on a first in,first out basis.


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1

Cleaning and maintenance

In the event that cleaning is necessary, elasto-mer products should be cleaned with warm,soapy water that does not exceed 30 C (85 F),and air dried at room temperature.

Solvents such as trichloroethylene, carbontetrachloride or hydrocarbons should not beused, nor should sharp-edged objects, wirebrushes, emery cloth or sandpaper.

Elastomer/metal combinations can be cleanedusing a 1:10 mixture of glycerine and alcohol.

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2

Radial shaft seals

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Outside diameter design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54SKF Bore Tite Coating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Garter springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55Tolerances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Sealing lip design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Auxiliary lips. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Coaxiality and runout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Coaxiality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59Runout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Axial movement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Permissible speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65Lubrication of paired arrangements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Friction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Chemical and thermal resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Seals under pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Shaft requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70Tolerances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70Surface roughness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70Surface finish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72Hardness and surface treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Lead-in chamfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Housing bore requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

47


50/483

Metal-reinforced seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74Seals without metal-reinforcement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74Tolerances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76Surface roughness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Seal installation, general industrial applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Seal installation, heavy industrial applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79Metal-reinforced seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79Seals without metal reinforcement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80Split seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80Cover plates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82Multiple HS seal installations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83Multiple HDS seal installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84PTFE seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Protecting the counterface surface against corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Designation system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88Metric radial shaft seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88Inch-size radial shaft seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Assortment and availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Seals for general industrial applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92HMS5 and HMSA10 seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

2.1 Product table: HMS5 and HMSA10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94CRW1, CRWA1, CRWH1 and CRWHA1 seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

2.2 Product table: CRW1, CRWA1, CRWH1 and CRWHA1 . . . . . . . . . . . . . . . . . . . . . . . . . . 101CRW5 and CRWA5 seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

2.3 Product table: CRW5 and CRWA5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157HDW1 seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

2.4 Product table: HDW1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161

CRS1, CRSH1, CRSA1 and CRSHA1 seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1622.5 Product table: CRS1, CRSH1, CRSA1 and CRSHA1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

PTFE radial shaft seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170HM and TL seals for grease lubricated applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

2.6 Product table: HM and TL seals . . . . . . . . .

Documents

Industrial Shaft Seals Cataloque