| 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%. |
