Ceramic-to-Metal Sealing with Kryoflex®

Only Kryoflex Ceramic-to-Metal Seals are Hermetic Now… And Forever!

Kryoflex polycrystalline ceramic — a multiple-phase derivative of ceramic oxide crystalline silicates— was developed by the Hermetic Solutions Group as a ceramic-to-metal alternative to compression glass and metallized alumina ceramics.

Chemically active Kryoflex provides, by means of oxygen pinned valence bonding, a direct union during the fusion processing of a ceramic to metal entity. This consistent chemical and mechanical bond is secured by the randomly organized crystalline structure, which allows this material to relieve stresses from within itself.

Kryoflex ceramic-to-metal seals provide a resistance of 1×1018 ohms/cm. It easily maintains resistance values exceeding 50,000 Megohms — even in micro-miniature designs. Stand-off voltage capability is such that breakdown will always occur in the air media surrounding the terminal and never through the dielectric.

Neither Vibration — Nor mechanical thermal Shock — will degrade Kryoflex ceramic-to-metal hermetic seals.

Kryoflex is a key technology that allows the Hermetic Solutions Group to deliver hermetic connectors that withstand extreme temperatures, pressures, and hazardous chemicals.

The Hermetic Solutions Group’s Kryoflex family of materials offer options for adjustable coefficients of linear expansion, so there are options for a wide variety of shell and conductor materials. Kryoflex does not require the addition of formers, so the material remains useful as an insulator from 400°F to +1,400°F with no loss of hermetic integrity.

Because Kryoflex seals directly to copper alloys, our hermetically sealed ceramic-to-metal connectors have excellent current-carrying capacity. When used with aluminum, Kryoflex permits hermetically-sealed connectors to be robust and lightweight, while using copper alloy conductors. For applications requiring greater strength, Kryoflex also works well with titanium, stainless steel or Inconel shells along with platinum, platinum-clad titanium, or Inconel pins.

Kryoflex XTS - A specific formulation for sealing high reliability  electrical feedthru connectors in high-temperature, high-pressure environments.

Hermetic electrical feedthru connectors used in down-hole LWD (Logging While Drilling) and MWD (Measure While Drilling) applications face unique reliability challenges due to the highly elevated temperatures and pressures, as well as the corrosive water and moisture that may deteriorate electrical insulation and lead to catastrophic electrical failures. To help our customers better solve those challenges, the Hermetic Solutions Group had developed a high-strength Kryoflex XTS sealing material - a diamond-like polycrystalline ceramic that provides a highly reliable hermetic seal for feedthru connectors that operate in high-temperature and high-pressure water/fluid based downhole harsh environments.

Kryoflex XTS sealing material can be used to seal conductive pins (X750, Alloy52, BeCu, Ti-alloy, Pt/Ir etc.)  made from a variety of materials into a range of metal shell (Inconel alloys, Ti-alloy, Kovar, and stainless steels) designs and compositions. The sealed electrical feedthrus manufactured with this material have been evaluated under 300oC/30,000PSI water-fluid simulated downhole harsh environments. Figure 1 below shows the duration of the HPHT electrical feedthru package test under 200oC/30,000 PSI simulated downhole water-fluid conditions. The connector remained hermetic to 1x10-9 cc/sec. He@ 1ATM.


Figure 1.









Under those conditions, Kryoflex XTS sealed electrical feed-thru connectors also exhibit high levels of insulation resistance. The Figure 2 shows that an electrical feedthru sealed with Kryoflex XTS sealing material could have ~10,000 MW electrical insulation resistances even at 300oC, 2X the industrial accepted 5,000 MW standard requirement.


Figure 2.










Electrical feedthrus sealed with Kryoflex XTS ceramic sealing material  also exhibit exceptional material bonding strength when exposed to the high-levels of shock and vibrations that these components are exposed to while under temperature and pressure. Figure 3 below shows the results of a 0-30,000 PSI pressure shock-cycle test at ambient and 200oC. Again, the feedthru passed hermetic testing to 1x10-9 cc/sec.He@ 1 ATM.


Figure 3.










The Kryoflex XTS sealing material has not only high mechanical strength but also has high voltage application that could be up to 45KV while keeping 5,000 megaohm insulation resistance.  Furthermore, Hermetic Solutions group (HSG) provides finite-element-analysis (FEA)-based HPHT electrical feedthru and connector designs that ensure sufficient reliability and performance under -100C to 300C and 0 to 30,000 PSI harsh conditions.  Figure 4 below shows a typical FEA-based design on a HPHT bulkhead feedthru design with Inconel 718 as metal header, 0.064” diameter Inconel X750 as pin material, for 5KV/2.5A downhole logging tool application.  The performance of such a bulkhead feedthru at zero pressure condition has a safety factor of better than 2 at temperature of <25oC and has a safety factor of better than 3 at temperatures of 150-200oC.  Since Kryoflex XTS material has about 103 KPSI compressive strength, it enables such a HPHT feedthru to have 35KSI compression capacity with safety factor of 3.   Thus, all designed electrical feedthru assembly will be of safety factor of 3, operable under 30 KSI pressure and 300oC temperature downhole or subsea environment. In addition, the hydrophobic properties of the Kryoflex XTS sealing material allow HSG electrical feedthrus and connectors applicable in both water-based and oil-based mud/fluid wellbores.


Figure 4.

Kryoflex XTS represents a significant advancement in hermetic sealing technology for high-pressure, high-pressure applications. To learn more about this material, please download our whitepaper.

Our Commitment to Quality

Our commitment to quality  helps ensure our customers are successful with their customers. And when we say “quality,” we don’t just mean producing the highest quality products, because that goes without saying; for the Hermetic Solutions Group, exceptional quality extends to our processes, the way in which we interact with our customers, our employees and the world. Quality is how the Hermetic Solutions Group does business.

Our Products

We offer innovative solutions and produce state-of-the-art products for Defense & Aerospace, Energy, Industrial,Medical and Optical Networking industries.

Our Services

We’re not just a manufacturer; we offer our customers value added services to help them succeed when in-house capacity is not an option.