BMG, exclusive distributors in Southern Africa for Hallite Seals, supplies industry with a range of quality seals, which includes products designed especially for demanding earthmoving applications.

“Hallite sealing systems, manufactured from robust materials, enhance performance of hydraulic cylinders used in severe conditions in which earthmoving equipment operates,” says Ken Steel, general manager of BMG’s seals division. “Hallite’s design engineers and material technologists consider these tough conditions when designing new sealing systems. Careful attention is given to seal profile design and material selection and product properties are methodically studied to ensure the finished component has the required qualities.

Hallite’s sealing materials include nitrile rubbers, rubber and fabric compounds and thermoplastic elastomers – all proven to keep the system free from external contamination in demanding mining applications. “Seals are subjected to extensive testing that reproduces continuous operating conditions where leakage, dynamic and breakout friction are recorded and performance factors like pressure, speed and temperature are carefully monitored.”

The latest sealing products, available nationally from BMG, include Hallite 80 rotary pressure seals, designed specifically for use in hydraulic swivel joints in earthmoving equipment. The Hallite 80 swivel seal is a one piece double acting seal which replaces two part seals typically used in swivel joints. These rotary pressure seals are manufactured in high specification polyurethane, Hythane 181, to provide easy installation and efficient sealing characteristics.

The elastic and flexible nature of this material enables each seal to be easily fitted in its groove and its hard wearing nature extends service life. Special pressure activation grooves are incorporated in the seal’s design to enable an immediate seal of the joint.

Hallite 735 compact double acting piston seals also form part of BMG’s range. These heavy duty seals, which have a compact design, are suitable for low to high pressure and medium to heavy duty earthmoving applications. The assembly comprises a standard self lubricating wear resistant bronze filled, or glass filled PTFE cap ring, which is loaded by a NBR energizer. Thermoplastic split anti-extrusion rings support the seal on both sides and prevent extrusion of the energiser and cap ring.

Other features of this range include various material options to suit specific applications, low friction during operation and extended service life. Hallite 714 high pressure double acting seals have an excellent static load holding capability and are ideal for re-phasing cylinders to ingest contamination in earthmoving equipment.

The re-inforced, heat stabilized, thermoplastic sealing face has step-cut joints for easy installation.

The design of these compact seals tolerates a considerable
extrusion gap, thus reducing the possibility of piston-to-bore contact
when used with remote bearings. The square section nitrile rubber
energizer responds quickly to pressure changes, providing excellent sealing characteristics under all pressure conditions.

These seals, which are capable of passing over ports, have excellent wear and abrasion resistance. BMG’s extensive range of sealing
products meets the demands of the OEM and end user for efficient
performance from equipment that needs to work harder and for longer periods as productivity levels increase.