General consideration: All measurements are indicated in millimeters unless otherwise mentioned.

The first section of the part number refers to the type of seal you want to select.
All the different types of High Tech Metal Seals are discribed on page 6 and 7 of this catalogue.

As shown on the figures above, C seals without spring have a smaller sealing surface (after compression) though we need a much higher load to compress the seal. (We can make the same remark For O-seals, with or without spring.)
Depending on the application we propose either spring energized or non spring energized seals.

This part of the HTMS part number refers to the seal diameter (0,01 mm) without plating/coating thickness.
Seal types for internal pressure and all axial seal types: Diameter Seal Outside (DSO).
Seal types for external pressure: Diameter Seal Inside (DSI).

2,39 is the cross-section (free-height) of the seal in mm. The letter M refers to the wall thickness of the seal (in this case medium). Sealjackets and springs are available in different standard hights and wall thick­nesses:

Please contact HTMS for non-standard dimensions.
For our standard cross-sections and wall-thiknesses we refer to the specific tables.

The material code "1/1" indicates the material used for jacket and spring. In this case both sealjacket and spring are made out of Inconel X-750. Code 1/9 for example means that the sealjacket consists out of Inconel X-750 (1) and the spring is made out of 302 stainless steel wire (9). The following table will give you a brief overview of the most common standard materials. Our engineering department will carefully select the right seal material for your specific application. Special stainless steels and high performance nickel alloys are our standard materials. Please contact HTMS for non-standard materials.

To obtain other sealing properties (higher load and springback values) our seals can undergo a variety of heat treatments. The different Heat Treatments are indicated by the temper code in the HTMS-partnumber. Beneath you can find a table with the different temper codes we can offer and recommend, depending on the specific application.

This last section in our part number determines the finishing layer and his thickness.

HTMS can offer a wide range of specialized platings and coatings which creates a ductile outer surface layer and ensures optimum sealing by filling out all imperfections in the mating surfaces. The plating or coating layer also reduces the coefficient of friction of the seal so the seal can slide and bed-down during compression what prevents galling.

Seal coatings and platings not only provide better physical properties to the seal (ductility and softness) but are also chosen to withstand high temperatures and agressive environments (corrosive or oxidizing sealing conditions).

The table below can be helpful to determine the type of plating needed. (In most cases silverplating is an added value to improve sealing capacity and to lower leakrate.)

The finish of the mating surfaces is an important factor in the choice of the plating/coating thickness. Rougher surfaces require thicker finishes for good sealing capability.

A soft plating like lead can handle larger Ra-values than for instance nickel. The table below is a helpful
guideline to choose the finish thickness.

Thicker finishes are available on request (up to 0,25 mm). Our plating department can handle special tolerances on silver finishes.

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Resilient metal seals from High Tech Metal Seals NV are used in the most extreme environmental conditions. Spring Energised Metal C Rings are used under extreme conditions where temperature can range from cryogenic up to extreme high temperatures, such as 800°C.
To serve the harsh conditions in today’s Oil and Gas exploration, High Tech Metal Seals NV designs and manufactures resilient metals seals which comply and exceed the ISO 15848 leakage requirements for valves intended for application with volatile air pollutants and hazardous fluids. High Tech Metals Seals are manufactured from high alloy materials so that the finished product complies with NACE MR0175 requirements. Silver plated Metal O rings or Metal C Rings, because of ductile layer are successfully used in high vacuum applications. Silver plated or PTFE coated spring energised C Rings and Metal C Rings comply and exceed the ISO 15848 leakage requirements, from cryogenic temperatures up to extreme high temperatures and pressures. In nuclear applications, particle research, and other radiation application, typically high load resilient metal seals, such as spring energized metal C Rings or Metal O Rings, with a ductile layer of silver are successfully used. High Tech Metal Seals NV, seals for extreme environmental conditions are particularly suited for high pressure. The system pressure assist in maintaining intimate contact with the mating flanges.