Variable Spring Terms

Variable Spring Part No. Categorized by spring rate.
Variable Spring Size Categorized by load range.
Variable Spring Type Categorized by physical shape.
Hot load / Hot setting / Operating load The weight the variable spring has to support while the pipe line system is in operation.
Cold load / Cold setting / Installed load The weight the variable spring has to support while the pipe line system is NOT in operation. This is also called pre-set load.
Movement/ Travel The measure of a vertical travel distance of the pipe which is supported by the variable spring when the pipe line is in operation.
Movement/ Travel direction The movement direction, either UP or DOWN of the pipe while in operation compared to its resting point (not in operation).
Spring rate Lbs/in of spring travel.
Hydro-tested load The test which determines whether or not the variable spring will support the operating load.
Travel stops Limit the spring travel at the top and bottom to a small percentage beyond the specified range. In addition, they prevent the spring from moving while the spring is not in operation (in pre-set mode) or in hydrostatic testing phrase.
Load flange Top Plate on which the pipe load rests.
Variability The amount of supporting load variation on horizontal piping. The percentage of variability should not exceed 25%.