Variable Effort Supports are used to support the weight of pipework or equipment whilst allowing a degree of movement relative to the supporting structure. Where pipes transport hot (or cold) liquids or gases they expand (or contract) due to the difference between operating and ambient temperatures. It is necessary to support the pipe in operating and ambient conditions, whilst permitting movement between the two.

Variable Effort Supports may also be needed to cater for ambient temperature variation local to items of plant or long vertical pipe runs, or where pipes pass between buildings that may be subject to relative movement due to subsidence or earthquake.