O Ring Guide - James Walker - #2

Guide to 'O' rings

Our quality systems are third-party registered to BS EN ISO 9001:2000. We are also regularly assessed and quality approved by a wide range of industry bodies and individual customers including multinational corporations, utilities and government organisations.

In addition, we hold test equipment for all relevant BS, ISO, ASA, API, ANSI, DIN, DTD and NATO standards. Certificates of conformity are supplied on request. Packaging and labelling is available to individual specifications.

The 'O' ring, or toroidal seal, is an exceptionally versatile sealing device. Applications ranging from garden hose couplings to critical aerospace or refinery duties make it the world's most popular volume-produced seal.

'O' rings offer many benefits to design engineers and plant operators, they:

• Suit many static and dynamic duties.

• Occupy little space.

• Seal efficiently in both directions.

• Are compatible with most fluid media.

• Can work between -65°C and +315°C when made of elastomer - according to material type.

• Can function at temperatures down to -200°C when made of PTFE.

Today, the design engineer is faced with a bewildering array of 'O' ring statistics and advice. In this guide we simplify design data, give concise information on materials and facilitate part selection for specification and ordering purposes.

The result is a document that contains valuable information for use by buyers, designers and maintenance staff.

Selecting an 'O' ring 3

Selecting a back-up ring 3

Selecting a material 4

Coloured materials 4

How to order 5

General materials 6

Commercial 'O' rings 6

High performance materials 7

Guide to material use 8

Lubricants 8

Surface texture 8

Explosive decompression 9

FEP encapsulated 'O'rings 10

Back-up rings 10

Chart 50: Inch and metric sizes 11-17

'O' rings for pipe fittings 17

Chart 72: Metric sizes 18-20

Chart 17000: Inch sizes 21-22

Non-standard sizes 23

Design notes: General 24-25

Design notes: Housings 26-28 (fold out page 28 for easy reference)

'O' ring cord 29

'O' ring kits 29

Special packaging and kits 29

Our Materials Technology Centre houses one of Europe's most advanced facilities for elastomer batch production. At its heart is a computer-controlled internal mixer that holds formulae for over 300 of our elastomeric compounds.

Together with on-line rheometer testing, this gives us complete batch traceability, regardless of any release certificate requirements.

The post-curing of silicone and fluorocarbon elastomers is also under microprocessor control for temperature level and time. Each cure cycle is trace-recorded as a vital link in our quality chain.

Every 'O' ring we manufacture is visually inspected. This is backed by batch inspection of physical dimensions with an even closer study of mismatch, flash and other specific parameters.

Material Safety Data Sheets (MSDS) are available on request.

We now stock over seven million 'O' rings ready for same-day despatch. If the rings you want are not available off-the-shelf, we can supply them within days from our extensive manufacturing facility. With our flexible production schedules, we can meet the most urgent requests from industry.

Trademark acknowledgements

James Walker acknowledges the following trademarks as mentioned in this guide. All other names bearing the ® symbol are registered trademarks of James Walker.

Aflas® Asahi Glass PEEK™ Victrex plc

Dyneon™ 3M Dyneon Tecnoflon® Ausimont Spa

Hypalon® DuPont Performance Elastomers Viton® DuPont Performance

Kalrez® DuPont Performance Elastomers Elastomers

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