These couplings are a derivation of the standard DJ units incorporating central spacer tubes in composite material. They are specifically intended for use on long applications such as found on cooling towers, vertical pumps & marine drives. They can, however, be used on any application where the benefits are an advantage. The technology may, in certain cases, be applied to high-speed couplings. For further information please contact Bibby Turboflex.
	Advantages of DJCFT Couplings (These are in addition to those for the parent DJ couplings)
	Low mass – The use of composite material for the coupling spacer considerably reduces the unit mass which can simplify installation and extend machinery life. Temperature stability – Stationary long steel shafts will bow when subject to heating from one side only (e.g. sunlight on a cooling tower shaft) causing severe vibrations on start-up. With composite tubes the effect is negligible. Simplified installation – The DJCFT range of couplings are specifically designed to make installation simple. Less need for intermediate bearing supports – Composite shaft couplings can offer significantly higher lateral critical speeds than equivalent steel shafts. The result is that, for long shaft applications, it is frequently possible to use a single span shaft, eliminating the need for central bearings and all the installation and maintenance costs these incur. Improved bearing life – The reduced mass and inherently excellent balance of these units reduces bearing forces and can significantly improve bearing life.	Specific Notes The following section outlines data for the Composite Shaft Disc Couplings. The following points should be noted in relation to these products: • Momentary overloads of 2x and shock loads of 3x the stated rating are accepted by these units. • Larger rated units are available by special design. Please contact our staff for more information. • Misalignment data is shown on page 18. Materials The basic materials of construction for the DJCFT are as for the DJ couplings (see General Purpose Disc Coupling section) with the obvious exception of the central Spacer. The standard materials (bold type) and options (italics) are as follows. In addition, there are a number of coatings available as options. If there is a specific requirement for a material or coating not shown below, please contact our design team for discussion. Spacers ends: Carbon Steel Alloy Steel Stainless Steel Spacer tube: Carbon Fibre Glass Fibre High Modulus - Carbon Fibre Coatings: (steel parts) Phosphate Epoxy paint Galvanise Zinc spray.