Walkersele® D8 Radial Lip Seal

High Performance Sealing Technology

Issue 1

● Developed for marine applications

● Accommodates shaft eccentricity

● Resistant to cold flow / creep

● Withstands vibration and shock loads

● Service pressures to 150kPa

Registered Office: Lion House, Oriental Road, Woking, Surrey GU22 8AP, United Kingdom. Reg No. 2432592 England© James Walker 2011

James Walker & Co Ltd1 Millennium Gate, Westmere DriveCrewe, Cheshire CW1 6AY, UK Tel: +44 (0)1270 536000Fax: +44 (0)1270 536100Email: csc@jameswalker.biz CERTIFICATE No. FM 01269

BS EN 9100:2003 BS EN ISO 9001:2008

BP4400 1011/1mPIIL2774768

Walkersele® D8 Radial Lip Seal

Walkersele® D8 is a recent addition to our well-proven family of radial lip seals. It has been introduced primarily for marine propulsion applications where the seal arrangement must:• Protect bearings from the ingress of

seawater and other media.• Keep lubricants free from

contamination.• Prevent the leakage of lubricants to

the environment.

This seal’s trouble-free operational life has been proved by extensive testing on our dynamic rigs, combined with over 12 months of sea trials on working vessels plus applications in heavy industrial environments.

Walkersele D8 has been developed to withstand higher operational pressures than our popular Walkersele® D6. It also incorporates new lip geometry, that provides greater flexibility and lower lip loading than our D7 design, to accommodate shaft eccentricity.

The robust design of the D8 lip has been validated on marine applications where typical operating conditions have included elements such as vibration and shock.

Typical applications• Marine propulsion units.• Azimuth thrusters and large diameter

swivel units.• Stern gland seals.• Flooded gearboxes.• Process equipment — onshore as well

as offshore and marine.

Materials of construction

Our Walkersele D8 design is available in the following material combinations:

NM74/80 KC300 recommended for marine duties for housings with retaining plates. Flexible back of nitrile (NBR)-proofed aramid fabric; lip of NBR.

M1 for housings with retaining plates. Flexible back of nitrile (NBR)-proofed cotton fabric; lip of NBR.

M6 self-retaining seal for open housings. Nitrile (NBR), with a steel band located in its back. Retaining plate is needed to support lip heel when seal faces in-board.

M8 self-retaining seal for open housings. Fluoroelastomer (FKM), with a steel band located in its back. Retaining plate is needed to support lip heel when seal faces in-board.

M9 for housings with retaining plates. Flexible back of fluoroelastomer (FKM)-proofed aramid/glass fabric; lip of FKM.

Range of Elast-O-Lion®- based materials for housings with retaining plates. These typically have a flexible back of hydrogenated nitrile (HNBR)-proofed aramid/glass fabric, and a lip of HNBR. Material grade is selected to suit specific applications and working conditions.

Service capabilities

Pressure differential (max): 150kPa/1.5bar (21.75psi). Base of the seal must fully supported for pressures greater than 20kPa/0.2bar (3psi).

Shaft eccentricity accommodated (typical max): 3.0mm TIR — dependent on shaft diameter and speed.

Rotary shaft speed (typical max) NM74/80 KC300 & M1: 15m/s (2953fpm). M6: 12m/s (2362fpm). M8: 20m/s (3937fpm). M9: 25m/s (4922fpm).Elast-O-Lion®: 15m/s (2953fpm), dependent on grade.

How supplied

As Walkersele® OSJ, for On-Site Joining with our patented technique, in NM74/80 KC300, M1, M6 and Elast-O-Lion materials. Cartridge seals can be custom designed.

As Walkersele® SpringSafe in M1, M6 and Elast-O-Lion materials, with lip-energising spring intimately cured into its groove. Also, in normal split and endless form, in all quoted materials.

Please refer to our Walkersele® Radial Lip Seals brochure for sizing guidelines and surface finish requirements.

D6 D8 D7

Far left: Walkersele® D6 operates at a typical maximum pressure differential of 20kPa/0.2bar (3psi).

Middle: Walkersele® D8 operates at a typical maximum pressure differential of 150kPa/1.5bar (21.75psi).

Right: Walkersele® D7 operates at a typical maximum pressure differential of 400kPa/4bar (58psi).

Health warning: If fluoroelastomer (eg, FKM, FFKM, FEPM) products are heated to elevated temperatures, fumes will be produced which may give unpleasant effects, if inhaled. Whilst some fumes are emitted below 250°C from fluoroelastomers, the effect at these temperatures is negligible. Care should be taken to avoid contaminating tobacco with particles fluoroelastomer which may remain on hands or clothing. Material Safety Data Sheets (MSDS) are available on request.

Information in this publication and otherwise supplied to users is based on our general experience and is given in good faith, but because of factors which are outside our knowledge and control and affect the use of products, no warranty is given or is to be implied with respect to such information. Unless governed by type approval or contract, specifications are subject to change without notice. Statements of operating limits quoted in this publication are not an indication that these values can be applied simultaneously. To ensure you are working with the very latest product specifications, please consult the relevant section of the James Walker website: www.jameswalker.biz.

Environmental statement: This brochure is manufactured using advanced environmentally friendly technologies and follows the strict environmental standard BS EN ISO 14001.