O-Rings
Metric and imperial O-rings are produced from mould in different sizes, available in standard compounds such as NBR 70 ShA and FPM 75 ShA. Other compounds and/or hardness are available on-demand.
On request, we can separately supply O-ring cords in different compounds and sizes.
For non-standard large O-rings and without an existing mold we propose a hot-vulcanization manufacturing procedure. The O-ring is endless and without any evidence of splice: endurance and elasticity are very similar to moulded ones.
Although this procedure avoids the majority of jointed O-rings problems, it is important to take some precautions when handling hot-vulcanized O-rings and specifically:
- no excessive traction on splice
- bending radius on splice not bigger than ¼ of cord diameter
Additionally we can supply encapsulated O-rings, consisting of a seamless and uniform Teflon® FEP/PFA encapsulation, which completely encloses a core material of either VQM or FPM elastomers.
The encapsulated O-ring behaves like a highly viscous fluid, any pressure exerted on the seal is trasmitted pratically undiminished in all directions.
Made in a single piece for standard O-rings, the anti-extrusion rings SR have the function of preventing any damage to the O-rings, which they normally suffer if subjected to very high pressures or large gaps between the parts.
If the pressure affects only one side of the O-ring, only one anti-extrusion ring positioned on the side opposite to the pressure is enough; if pressure affects both sides, two anti-extrusion rings are required (one on each side).
Thanks to the elasticity of the polyester, these rings can be easily installed even if they are whole (i.e. without the typical cut of the PTFE rings). This prevents possible damage from pinching the O-ring at the cut site.
