Rotary Seals

Every item of rotating plant and equipment - from a humble lawn sprinkler to a jet engine or massive hydroelectric power scheme - relies on rotary sealing systems to keep it working safely and efficiently.

The four main points to consider are:

• Bearing protection
• Lubricant retention
• Exclusion of contaminants
• Safeguarding the environment by minimising leakage of media.

James Walker caters for these needs at every industrial level with two complete families of seals, and a unique installation technique that avoids shaft dismantling.

WALKERSELE® RADIAL LIP SEALS

WALKERSELE® OSJ - On-Site Joining

METAL CASED LIP SEALS

WALKERSELE® RADIAL LIP SEALS

Walkersele® is our family of radial lip seals for rotating shafts and rotary plant such as rolling mills, gearboxes, marine propulsion systems and tunnel boring machines.

Developed constantly over 50 years to keep ahead of customers' operating conditions, Walkersele offers invaluable benefits to industry.

As well as being high quality and cost effective they are:

• Available in unlimited sizes
• Easy to install and simple to remove
• Designed to suit each application
• Widely available ex-stock in standard sizes.

WALKERSELE DESIGNS

The main aim of a Walkersele is to retain lubricant within a bearing assembly. When manufactured with a secondary lip, or installed in pairs, they also prevent the ingress of liquid and solid contaminants.

Unlike many other spring-loaded lip seals, Walkerseles have no exposed metal components apart from the stainless steel toroidal spring. To reduce fitting time, most Walkerseles can be supplied in split form.

The following standard profiles are widely used.

Walkersele D6 - our most popular design

Minimal heat generation and shaft wear Flexible lip to accommodate shaft eccentricity Fabric-backed version can be supplied in split form Standard inch and metric sizes available ex-stock in nitrile (NBR) based materials Sizes from 10mm to unlimited shaft diameter

Walkersele D7 - pressure resistant lip seal

Flexible and robust lip profile maintains contact on misaligned or eccentric shafts Maximum operating pressure 4bar Does not need profiled lip support plates Sizes from 30mm to unlimited shaft diameter Available in self-retained or plate-retained forms.

Walkersele D6/DL - for aggressive environments

Walkersele D6 design with dust lip incorporated All the benefits of Walkersele D6, but can be used for simultaneous fluid containment and dirt exclusion duties.

Walkersele D1/DL - alternative for aggressive environments

Similar to Walkersele D6/DL design Alternative profile with dust lip incorporated within overall depth of seal.

Walkersele D5 - compact design

• Compact design of Walkersele
• Developed for applications where space is limited and a lip spring cannot be accommodated.   

Walkersele TBMS - for tunnel boring machines

• Very robust radial lip seals for protecting the bearings of tunnel boring machines working in the most abrasive environments.
• Well proven on major projects including Channel Tunnel (7.8m diameter) and Airport Link Railway, Sydney, Australia (11m diameter).

WALKERSELE® MATERIALS & CONSTRUCTION

The selection of material/s for a Walkersele depends on four factors:

• Compatibility with media to be sealed
• Stability at working temperature
• Wear resistance at the operating conditions
• Suitability for the operating speed.

The properties of our ten most commonly used Walkersele materials and construction methods are shown below together with their maximum operating temperatures and speeds.

M1 - Nitrile NBR

• Standard material for most Walkersele applications
• Construction - flexible rubberised-fabric back and rubber lip
• Maximum under-lip temperature 120°C
• Walkersele D6 maximum speed 15m/s
• Walkersele D7 maximum speed 12m/s.

 M5 - Butyl IIR

• For some media where Nitrile NBR is not chemically compatible
• Maximum under-lip temperature 120°C
• Walkersele D6 and D7 maximum speed 5m/s.

M6 - Nitrile NBR with steel band

• Incorporates encapsulated steel band in seal back
• For self-retaining seals in open housings
• Maximum under-lip temperature 120°C
• Walkersele D6 maximum speed 12m/s
• Walkersele D7 maximum speed 10m/s.

M8 - Fluoroelastomer FPM/FKM for high temperatures

• Incorporates stainless steel band in seal back
• For self-retaining seals in open housings
• Maximum under-lip temperature 200°C
• Walkersele D6 maximum speed 20m/s
• Walkersele D7 maximum speed 18m/s.

M9 - Fluoroelastomer FPM/FKM for high speeds

• Flexible rubberised back and rubber lip
• For applications where M1 Nitrile NBR is unsuitable due to operating speed or chemical compatibility limitations
• Maximum under-lip temperature 140°C
• Walkersele D6 maximum speed 25m/s
• Walkersele D7 maximum speed 22m/s.

NM28/80 & NM48/80 Nitrile NBR - lubricated compounds

• Nitrile rubber compounds incorporating lubricants
• For reduced wear and improved speed capability under adverse lubrication conditions
• Maximum under-lip temperature 120°C
• Walkersele D6 maximum speed 15m/s
• Walkersele D7 maximum speed 12m/s.

Elast-O-Lion® Hydrogenated Nitrile HNBR

• High strength elastomer for aggressive applications
• Increased wear resistance at high speeds
• Maximum under-lip temperature 150°C
• Walkersele D6 maximum speed 15m/s
• Walkersele D7 maximum speed 12m/s.

Fluolion® PTFE

• For chemical and food processing applications
• Maximum under-lip temperature 260°C
• Walkersele D6 maximum speed 3m/s.

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WALKERSELE® OSJ - On-Site Joining

Using our revolutionary and patented OSJ technique, a high-integrity Walkersele® can be fitted with the ease and maintenance economies of a split-type. But the installed unit has the fluid sealing performance of an endless seal.

Optimum sealing performance - achieved by our high-integrity joining technique. Cost effective - an 'endless' Walkersele is fitted on-site without a major plant strip- down or expensive on-site vulcanising. Easy maintenance - our OSJ technique is swift and straightforward. All components and fitting aids (except hot air gun) are supplied in the basic Walkersele OSJ kit

Walkersele OSJ is proven worldwide on applications as diverse as steel mills, power stations, sugar refineries and marine swivel joints.

DESIGNS, MATERIALS & SIZES

Walkersele OSJ is available in all Walkersele designs that have backs moulded from rubberised fabric. The elastomers used are nitrile NBR and fluorocarbon FPM/FKM, with a maximum operating temperature of 120°C imposed by the joint.

Seals for shaft diameters from 38mm to 700mm are readily available. Sizes above 700mm are swiftly custom-made to order.

FITTING PROCEDURE

The fitting of Walkersele OSJ radial lip seals can be undertaken by non-specialists after just a few hours of hands-on training. A video of the installation procedure is available.

Stage 1: Apply epoxy adhesive to joint faces.		Stage 2: Align joint accurately in moulded jig.		Stage 3: Clamp in position with steel band.		Stage 4: Cure epoxy adhesive with hot air gun.

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METAL CASED LIP SEALS

We supply one of the largest ranges of competitively priced metal cased lip seals for rotary shafts. Over 500 combinations of design and size in standard materials are stocked for immediate despatch.

Types SC & TC - our preferred designs

Standard lip material: nitrile NBR Max under-lip temperature 120°C Max surface speed 10m/s Case and spring: carbon steel, with stainless steel available on request Alternative lip materials: silicone or fluorocarbon rubbers.

Other designs supplied

SB • TB • SA • TA • SF • TF•SM • TM

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