September 2015

Custom Fabricated F-Type Variable Springs

Rilco Manufacturing custom fabricated these f-type variable springs for a local ethylene cracker unit. They are designed for an operating load of 18,000 lb. with an upward travel of 1/16". They are fabricated from carbon steel and hot-dipped galvanized. The variables include a PTFE, 25% glass filled slide plate (not pictured) welded on the top carbon steel flange, and a polished stainless steel plate is included to be welded to the bottom surface of the load support for movement of the pipeline.

Custom F-Type Variable Spring Pipe Supports

Variable springs are used to support piping which is subject to thermal expansion and other factors which cause the pipe support point to move. They are called “variable” because the force exerted by the “spring” varies through their range of travel. As the supported pipe moves upward, the force exerted by the “spring” decreases. Conversely, during downward travel, the force of the “spring” increases.

Variables support piping where thermal movements cause the system position and dimensions to change. They're also commonly used where the transfer of an uncontrolled load can cause damage to the equipment.

A “variable” spring may not necessarily be recommended in all the above applications, however. As an example, when the variability surpasses 25%, our constant spring support should be used.

Some of the optional design features you can include when ordering variables:

  • Limit stops - installed in order to accurately limit spring movement
  • Lifting lugs - available on all sizes of springs
  • Optional casing and component finishes
  • Available fabricated entirely from stainless steel, including coil

Below are various types of variable springs that Rilco offers. The type of “variable spring“ hanger to be utilized depends upon several variables. Those include the physical characteristics of the hanger attachment, whether it will be supported above or below the spring and the potential of interference from other components.

Types of Variable Spring Hanger Configurations

Do you have any upcoming projects that may require the need for variable spring supports?