Seals are used to prevent the ingress of fluid or particles in a wide range of mechanical applications.  Applications vary from traffic light enclosures to hydraulic mining equipment, fluids range from seawater to DOT brake fluid and pressures range from a couple of kilopascals to hundreds of megapascals. While some applications have been standardised, many seals require individual design.  Jehbco manufactures custom silicone extrusions for a range of non-standard sealing applications.

Seal performance is influenced by a number of factors.  These include:

• The nature of the fluid being sealed, whether it be liquid or gas;
• The condition of the sealing surfaces and presence of any grooves or roughness;
• Materials;
• Geometry;
• Force exerted on the sealing surfaces.

This last factor, sealing force, is useful not only in estimating performance, but is essential for proper design of the sealing system.  For example, in a gasket system (Figure 1), sealing force is exerted on the gasket by a series of bolts.  To design the bolting system, the designer must know the force required to compress the gasket and form a seal.

Figure 1: A gasketted flanged pipe joint.

Sealing force is often determined through guesswork and expensive in-field testing.  Jehbco are breaking this mould by developing custom tooling to measure force on our sealing products.  With these tools, Jehbco will be able to provide our customers with accurate estimates of sealing force required under specific conditions – for example, the force required to compress an o-ring by 20%, or the force exerted by a seal on an expansion joint when the joint is 10 mm wide.  Jehbco aims to use these tools to enhance your design processes so we can more quickly produce a silicone extrusion that meets your sealing requirements.

For more information on silicone seals and assistance, please contact us at Jehbco.