Fietz offers support rings for external or internal sealing applications in solid and slotted designs, up to 500 mm outer diameter, as well as in spiral designs up to 2,000 mm outer diameter – in every profile dimension.

Solid Support Rings

Unslotted support rings are used wherever particularly high loads are expected, as they provide the O-ring with uniform support across the entire contact surface. For applications involving rotational motion, helical motion, as well as high pressures, speeds, and temperatures, the unslotted design is preferable – provided this is structurally feasible.

PTSM^® Support Rings

When using slotted PTFE support rings, deformation and shearing frequently occur due to installation factors. If unslotted PTFE support rings are used, they must be calibrated after installation due to their low elasticity and consequently low shrinkage behavior.
In contrast, the Fietz PTSM^® support ring (PTFE Snap Mount) performs very well due to the material, which was specifically developed for high elasticity: Thanks to its strong recovery behavior, it is able to shrink to the required size – the bottom of the installation groove – even under extreme expansion. The design of the wall thickness between the inner and outer diameters eliminates the need for final calibration.
The necessary preload of the Fietz PTSM^® support rings is created by the so-called “Snap Mounting Effect,” a chemical property of the PTSM^® material. This means that the material strives to return to its original shape and “remembers” its initial state. During installation, the support ring is stretched beyond the shaft diameter. Manual or fully automatic installation is performed in three simple and safe steps using specially designed Fietz installation tools.
This prevents installation errors and guarantees an optimal fit for the Fietz PTSM^® support rings.

Slotted Support Rings

Slotted support rings from Fietz are available in straight and angled slot designs and are particularly suitable for use under medium loads and in unfavorable installation conditions, in both internal and external sealing versions.

Spiral Support Rings

The use of spiral support rings is recommended whenever extreme temperatures are expected. Because the spiral design allows the support ring to expand or contract without changing the inner or outer diameter, it maintains its function even under significant temperature fluctuations. Spiral support rings can also be used where non-standard components require compensation for diameter tolerances.