- Catalogs
- James Walker
- O Ring Guide
O Ring Guide
O Ring Guide
This document serves as a comprehensive guide on 'O' ring sealing systems, emphasizing their versatility and widespread application across industries, from garden hoses to aerospace. 'O' rings are noted for their efficiency, compact design, and compatibility with various temperatures and fluid media.
The company maintains a stock of over seven million 'O' rings for immediate dispatch and can quickly manufacture custom sizes to meet urgent industry needs.
The company complies with BS EN ISO 9001:2000 quality standards and undergoes regular assessments by industry bodies. They provide certificates of conformity and offer customized packaging and labeling.
The Materials Technology Centre is equipped with advanced facilities for elastomer production, ensuring complete batch traceability and quality control through computer-controlled processes.
The document acknowledges trademarks from companies such as Aflas®, Dyneon™, and Viton®.
The guide offers detailed instructions on selecting 'O' rings, back-up rings, and materials, including charts for different sizes and specifications to help users match existing 'O' rings or select new ones for specific applications.
The guide details various materials used for 'O' rings, such as nitrile, chloroprene, and natural rubber, each with specific properties and suitable applications.
Instructions are provided for ordering 'O' rings and back-up rings, specifying sizes, materials, and application conditions to ensure the correct product is supplied.
The document includes design notes for housing and application considerations to ensure optimal performance of 'O' rings in various settings.
This guide is a valuable resource for buyers, designers, and maintenance staff, simplifying the selection and ordering process for 'O' rings and related components.
This section provides a comprehensive overview of various elastomer materials, their properties, and applications, including Ethylene-propylene (EPM/EPDM), Butyl, Epichlorhydrin (ECO), Chlorosulphonated polyethylene (CSM), Polyurethane (AU/EU), Fluorosilicone (FVMQ), and Silicone (VMQ).
- Ethylene-propylene (EPM/EPDM): Excellent resistance to weathering, ozone, and various chemicals. Suitable for use with water up to +180°C.
- Butyl (IIR): Low gas permeability, ideal for vacuum and high-pressure gas applications.
- Epichlorhydrin (ECO): Good resistance to mineral oils and fuels, but limited by poor compression set resistance.
- Chlorosulphonated polyethylene (CSM): Excellent weathering resistance, not recommended for dynamic seal applications.
- Polyurethane (AU/EU): High tensile strength and wear resistance, but stress relaxation above +50°C limits use in 'O' ring applications.
- Fluorosilicone (FVMQ): Suitable for static seals in aerospace fuel systems, with limitations similar to silicone.
- Silicone (VMQ): Good resistance to weathering and high temperatures, but limited by high gas permeability and low tensile strength.
General purpose 'O' rings are available for less critical applications, offering competitive prices and full traceability. They come in a wide range of materials and sizes, including non-standard sizes to meet specific customer requirements.
- Fluoroelastomers (FPM, FKM): Efficient under severe chemical conditions and high temperatures, with various grades available for specific applications, including those resistant to explosive decompression.
- Elast-O-Lion® (HNBR): High-performance hydrogenated nitrile compounds with excellent oil/fuel resistance and superior mechanical properties.
- Kalrez® (FFPM): Offers almost universal chemical resistance, suitable for continuous operation at high temperatures.
Recommendations for lubricants to be used with 'O' rings are provided, along with guidelines on surface texture for precision-moulded 'O' rings.
The document discusses the phenomenon of explosive decompression damage in elastomeric components and the development of ED-resistant elastomers to mitigate these issues.
The document serves as a detailed guide for selecting the appropriate elastomer materials for various industrial applications, emphasizing the importance of understanding material properties and limitations.
- FKM: Combines improved low temperature capability with excellent thermal and chemical properties. Resistant to explosive decompression (ED) in hydrocarbon applications.
- Elast-O-Lion 101: Hydrogenated nitrile (HNBR) with high mechanical strength and wear resistance. Resistant to many oilfield chemicals and explosive decompression.
- Elast-O-Lion 985: HNBR with improved low temperature capacity but reduced mechanical properties and ED resistance compared to Elast-O-Lion 101.
- AF69/90: Aflas® (TFE/P) based ED resistant grade with excellent resistance to oilfield media and steam.
ED is a phenomenon in the oil and gas industry, occurring with rapid gas pressure drops, causing damage in various sealing applications.
Encapsulated with FEP fluoropolymer, these are used when standard elastomer ‘O’ rings lack chemical resistance and solid PTFE ‘O’ rings lack elasticity. Suitable for static duties and slow rotary applications, they offer excellent chemical resistance, operational temperature range, low friction, and better elasticity than solid PTFE.
Prevent extrusion of ‘O’ rings, made from PTFE, PEEK™, and filled PTFE. Recommended for high-pressure applications or low strength elastomer ‘O’ rings. Two back-up rings are needed for double-acting applications.
Provides dimensions for ‘O’ rings and back-up rings in both inch and metric sizes, reflecting standards in the UK and USA. Suitable for both dynamic and static applications.
‘O’ rings function by deforming to create a seal. Rubber's high bulk modulus makes it nearly incompressible, requiring deformation for sealing. The allowable deformation varies by application: up to 3% squeeze for cylinder grooves, 4% stretch for piston grooves, and specific limits for flange and triangular grooves. Housing tolerances must meet specified formulae, and surface finishes should not exceed 0.8µm for static parts and 0.4µm for moving parts. Maximum diametral clearance must not be exceeded to prevent extrusion gaps.
‘O’ rings are suitable for pressures up to 100bar; higher pressures require back-up rings. For stuffing boxes, piston-type grooves are recommended. In reciprocating applications, only certain ‘O’ rings are suitable, and rotary applications are limited to low peripheral speeds.
Standard tolerances apply to NBR medium nitrile material PB80. Non-standard housing diameters may require slight stretching or squeezing of ‘O’ rings. For explosive decompression environments, use the smallest diameter section that maintains sealing efficiency. Store ‘O’ rings according to BS ISO 2230:2002 or BS 4F68 (2002) guidelines.
Tables provide metric and inch groove dimensions for various applications. Housing arrangements must consider groove width, radial depth, and diametral clearance. Symbols used in design include ‘O’ ring diameter section (A), shaft diameter (C), and groove width (E), among others.
PTFE products emit fumes at high temperatures, which can be harmful if inhaled. Avoid contaminating tobacco with PTFE particles. Material Safety Data Sheets are available upon request.
‘O’ ring kits offer a selection of rings for maintenance engineers and refurbishers, providing convenience and quality for various industrial applications.
- Metric Sizes (Order Code: ZL000186): Contains 404 nitrile elastomer rings of 70 IRHD in 30 sizes ranging from 3mm ID x 2mm section to 45mm ID x 4mm section.
- Inch Sizes (Order Code: ZL000097): Contains 382 nitrile elastomer rings of 70 IRHD in 30 sizes ranging from 1/16 inch ID x 1/16 inch section to 1 3/4 inch ID x 1/4 inch section.
- Includes tools and nitrile elastomer O-ring cord of 70 IRHD in 14 different 2m lengths, ranging from 1.78mm to 8.0mm in diameter.
- Comes with a tape measure, retractable blade knife, splicing aid, adhesive, and full instructions.
- Available in metric and inch cross-sections in various elastomers such as Fluorocarbon, Nitrile, Ethylene-propylene, Neoprene, and Silicone.
- Standard cross-sections range from 1.6mm to 12.7mm.
- Manufactured to BS3734-1:1997 and ISO3302-1:1996 standards.
- Custom packaging and branding available for O-rings, including individual bagging and complete sealing kits.
- Custom-branded kits can include company name and logo for resale purposes.
- James Walker Group has multiple international offices, including locations in Australia, Benelux, Germany, France, Iberia, Ireland, Italy, USA, New Zealand, Norway, Singapore, and South Africa.
- For further details or to order, contact local offices or visit www.jameswalker.biz.
Catalog excerpts
The comprehensive guide toOђ ring sealing systems, including > ● Oђ ring selection > ● General & high performance materials > ● Housing design & tolerances > ● Kits, cords & accessories > High Performance Sealing Technology size="-1">
Open the catalog to page 1
EXAMPLE: PTFE spiral back-up ring touse with a 49.4mm ID x 4.1mm DS Oђ ring on a 50mm diameter shaft. Housing width 7.1mm, depth 3.5mm. Subsequent orders When re-ordering from James Walker, please state the Re-Order Part Number (eg, OB-03400X) shown on our documentation that acknowledges yourprevious order. Our computerised re-ordersystem will ensure swift service. Back-up rings Chart 50, metric sizes When ordering Chart 50 back-up rings tomatch our suggested metric shaft and cylinder sizes, please use: > The following information and exampleswill enable you to order the correct ֑O ring and back-up...
Open the catalog to page 5
Fluolion > (PTFE) Fluolion > ή is the registered trademark ofJames Walker products manufactured from polytetrafluoroethylene. PTFE is anextremely inert material, unaffected byvirtually every known chemical including most acids, alkalis and solvents. These exceptional properties make PTFE the ideal material for Oђ ring back-up rings.The flow characteristics of PTFE understress are usually a disadvantage in Oђ rings. Fluoroelastomers (FPM, FKM Fluoroelastomers operate efficiently under severe chemical conditions and at higher temperatures where many other sealmaterials cannot survive. According...
Open the catalog to page 7
Explosive decompression damage isstructural failure in the forms of blistering, internal cracking and splits caused when the gas pressure, to which the seal is exposed, is rapidly reduced from high to low. Inorder to overcome many of the problems associated with high pressure gas systems, we have conductedintensive materials developmentprogrammes over the last 20 years. Much of this work was carried out in collaboration with equipment manufacturers, major oil and gasoperators, and research bodies.We offer five standard grades of EDresistant elastomer, all of which have been extensively validated...
Open the catalog to page 9
FEP encapsulated Oђ rings have a core ofelastomer that is completely covered with aseamless sheath of FEP fluoropolymer.The elastomeric core is normally eitherfluorocarbon or silicone.An encapsulated Oђ ring is generally usedwhen: Although FEP encapsulated Oђ rings are most suited to static duties, they may beused with slow, short movements on rotaryapplications such as valve stem sealing. Their advantages are manifold, including: > ● Excellent chemical resistance to a widerange of media please consult our Technical Services Team for furtheradvice. > ֢ Astandard elastomer Oђ ring hasinadequate...
Open the catalog to page 10
Pressure restrictions Oђ rings are generally suitable for pressures up to 100bar. Where higher pressures are involved, we recommend the use of back-up rings, as described onpage 10.For stuffing box applications werecommend piston-type grooves, although triangular grooves are generallyacceptable for pressures below 100bar(see Figures 7 and 8). > How Oђ rings work 72 and Chart 17000 . The amount ofallowable deformation varies according to the application, as follows: Rubber has a very high bulk modulus and istherefore virtually incompressible. This means that an Oђ ring must be deformed onthe diameter...
Open the catalog to page 24
These three boxedkits represent excellent value for money in terms of quantity, quality and convenience.Each kit has beencarefully assembled for maintenance engineers andequipmentrefurbishers who need a good selection of rings constantly available to suit many industrial applications.The boxes are designed to withstandindustrial maintenance activities, and have partitions to hold all items separately and securely. From the kitlayouts, users can readily see whenthey are running low on a particular size of ring or cord. Oђ ring sealing kit metric sizes Box containing nitrile (NBR) elastomer rings...
Open the catalog to page 29
Compression packingsGaskets & jointingsHydraulic sealing products > BP4179 305/10mML-011653 Registered Office: Lion House, Oriental Road, Woking, Surrey GU22 8AP, UK. Reg. No. 2432592 Englandҩ James Walker 2005 size="-1">
Open the catalog to page 30Archived catalogs
Sealing Products & Services16 Pages
Compression Packings Guide36 Pages
Gaskets manual40 Pages
Hydraulic Seals6 Pages
- Liebherr plastic seal
- Machine foot
- Liebherr O-ring seal
- Liebherr lipped seal
- Liebherr metal seal
- NBR gasket
- Mechanical seal
- Metal foot
- Flat gasket
- Liebherr PTFE seal
- Pipe expansion joint
- Liebherr rubber seal
- Elastomer seal
- Liebherr piston seal
- Liebherr bar seal
- Anti-vibration foot
- Spring mechanical seal
- Round bellows
- Rubber pipe expansion joint
- High-temperature seal