Resilient metal seals often have to perform under extreme conditions. Standard solutions as given in this catalogue may not always fulfill these requirements.
In case the application requires seal properties outside the scope of the standard designs, HTMS can develop a seal with the necessary physical properties.
Close cooperation with universities and material suppliers allows HTMS to optimize the seal characteristics in no time.
At all times it is recommended to select the biggest possible cross section for a given diameter. By doing so, the useful spring back will be at its largest, enabling performance within the widest possible tolerance range for that given diameter (line C-D) and as such creating a more robust sealing solution. A higher spring back allows more flange movement/rotation due to internal or external loads.
Plating – Coating
With modern state of the art equipment, HTMS provides first class plating and coating services. Our in-house plating facility includes gold, silver, copper, nickel and tin plating. HTMS also runs a coating facility for applying PTFE as a soft layer on the mating surface of the seal.
The typical plating or coating thickness for seals is 50 microns. Adhering to the base material this layer will flow into the groove surface asperities under the seating stress. Softer materials such as tin and PTFE require a lower seating stress than for instance silver or gold. Nickel, being a relatively hard plating material, requires the highest seating stress.
Soft metal based plating can achieve a He-tightness of 10-10 Pa.m³/s. PTFE coating will have a limit of 10-6 Pa.m³/s because of the porosity of PTFE for Helium.