Common knowledge about springs that aren't so common.
Difference between mechanical snubbers and springs
A mechanical snubber protects components from excess shock or sway caused by seismic disturbances or other transient forces, such as earthquakes and landslides. In contrast, variable spring hangers only support a structure for thermal expansion or contraction. Additionally, a spring hanger is not a safety component, unlike snubbers.
WHAT IS "ROD TAKE-OUT" IN SPRING SUPPORTS?
The rod take-out (RTO) is the amount of space between the upper and lower attachment points of the spring hanger assembly.
Spring hangers and travel stops.
Travel stops are devices that temporarily lock the moveable parts of a spring hanger in a fixed position, enabling the load to be transferred to the supporting structure while maintaining the piping at the desired elevation.
WHAT IS THE PURPOSE OF THE SPRING "LOCK" ON A VARIABLE SPRING CASING?
The spring lock mechanism’s purpose is to provide pre-loaded support. Hydro-testing must be done with the lock in place to prevent the hanger assembly from getting damaged.
WHEN SHOULD THE SPRING SUPPORT LOK BE ON?
Spring supports should always be locked when the load is removed at that support location. The locking prevents the stored energy of the spring coil from suddenly releasing when the spring is disconnected.
HOW TO REMOVE A SPRING SUPPORT?
To remove spring supports, first, you must ensure that the spring is at its designed cold (installed) position. Next, re-install the travel stop(s) in the support. Install adequate temporary supports for the piping system and finally remove the spring support from the piping system.
WHAT IS A COLD SPRING?
Cold Spring is the intentional deformation of piping during assembly to produce a desired initial displacement and reaction. Cold spring support is beneficial in the way that it serves to balance the magnitude of the response under initial and extreme displacement conditions.