John Crane has launched a new range of H Series high performance power transmission couplings that combine the proven performance of its original Metastream® range with many new benefits. This allows the new Metastream H Series couplings to be used on numerous types of applications including turbocompressor machinery, turbine generator sets, marine turbine propulsion units, boiler feed pumps and development test stands.

The outstanding reliability of the original Metastream® products has been proven in use in the world’s energy, process and transport industries for well over30 years. By re-engineering these couplings from basic design principles, John Crane has been able to extend the boundaries of existing technology and create the H series products. These new lightweight, high performance couplings can satisfy both today’s requirements, and those of tomorrow, especially in such demanding areas as turbomachinery applications.

They offer such advantages as reduced moment configurations, optional arrangements for larger diameter shafts and integral shaft flanges, high balance and reliability characteristics, full compliance with ISO10441 (API 671) and the ability to optimise weight and flexibility to suit individual applications.

In response to the need to configure couplings to suit specific requirements the new H Series products incorporate many practical advantages. These include a backup gear drive that is configured to protect the membranes in the event of a failure or high overload torque, an option for electrical insulation on electric motor drives or turbine generator applications, torque limiting devices such as shear pins and hydraulic limiters, and a torque measurement capability that allows critical high performance machinery to be accurately monitored.

The H Series range includes three different families of coupling. The H-FE units feature a transmission unit that combines high torque capacity with low weight and are ideal for use on electric motor or generator drive applications where larger shaft sizes are generally in use. The reduced moment H-RE couplings use two factory assembled hub/flexible membrane units and a detachable spacer that produce a high integrity coupling suited for most medium speed and high speed compressor drives. Finally, the high integrity H-CE couplings offer the lowest possible overhung moments plus additional shrouding of the flexible elements and bolts, making it ideal for higher speed compressor drives.

The standard disc material is AISI 301 stainless steel which provides a special combination of high strength and resistance to corrosion. For high temperature or corrosive applications other materials such as Inconel® can be provided.

This flexibility is also reflected in the variety of disc options which are available. These include the HS Series 6-bolt disc design that provides maximum misalignment capacity for high thermal movement applications. 8-bolt discs feature on the HL Series couplings which combine the high torque capacity and flexibility required for most high speed applications, while the HT Series 10-bolt discs offer higher torque capacity that is particularly well suited to motor or generator drives with high torque peaks, low weight and low misalignment requirements.

Email: louise.palmer@johncrane.co.uk