Constant fill type fluid couplings offer a set performance characteristics that can be altered, permanently, by changing the fixed fluid level within the allowed range that does not result in excessive continuous slip. These are available with different levels of delay chambers for extended starts.

Variable fill type fluid couplings are dynamic, allowing for continuous control of the fluid into the working circuit. This offers better dedicated control of starts in response to speed readings and control of load sharing in response to tension or current readings, etc.

Joe Dos Santos ■

Depending on the starting, load sharing and target tension requirements of your application it may be possible to use a variable fill coupling in place of VFD control but you cannot get reduced speed on a continuous basis with a variable fill coupling. At similar cost VFD control is a better more versatile solution.

Joe Dos Santos ■