Glass-to-Metal Seal —A Reliable Design of Hermetic Seal Connector in Petroleum Field

Sunkye Hermetic Sealed Connectors enable efficient electrical signal and power transmission in severe situations like high temperature high pressure and highly corrosive chemicals.

Glass-to-metal sealing is a technique to hermetically insulate electrical conductors that pass from one side of a barrier to the other. The glass melts to both the package and pin, it can act as an airtight barrier and, in the meantime provide insulation between the housing and the pins. In the oil and gas field, as hermetically sealed feedthroughs used to conduct power or signals through the metal walls of vessels of liquefied gas tanks, they must operate reliably for the long term.

Glass-to-metal seals can be manufactured for high-temperature high-pressure connectors onshore and offshore, this type of seals are suitable for high-pressure applications (up to 60,000psi).  High-temperature operation from -55 degrees to 350 degrees.

Glass to metal seal applications in Oil and gas fields are sub-sea cable termination & condition monitoring, containment seal/fire barrier and wireline tools (measurement/logging whilst drilling), etc. So, it is true that the feedthroughs require hermetic or airtight seals that can withstand severe conditions such as high temperature, high pressure, vibration, moisture, and difficult chemical environments.

Sunkye High-temperature high-pressure connectors of glass-to-metal-sealed are protected against extreme conditions and are engineered for very high reliability. The glass is a good electrical insulator and it has low thermal conductivity, along with the capacity to withstand high operational pressure and temperature. The housing material is Kovar, this type of matched seal have the advantage that only small levels of residual stress are present and the feedthrough can withstand very high temperatures.

■ Random vibration:10Hz-2000Hz, 0.3G²/Hz, acceleration 20G, 175℃ .4h on direction X, Y, Z.

■ Shock:490m²/s, 11ms

■ Endurance: 500 cycles

■ Dielectric withstanding voltage: 1000VDC, 60s, leak current≤ 5mA

■ Normal temperature insulate resistance:≥5000MΩ (500VDC,normal-tem.)

■ High temperature insulate resistance: ≥500MΩ (500VDC,200℃)

■ Rated current: 1A continuous current

■ Temperature range: -55℃ to +200℃

■ Operating pressure: 0 MPa to 140MPa

■ High temperature life: 200℃,600h

■ Temperature shock: -55℃ to +200℃,15 cycles, the temperature switching time is ≤ 15 min

■ Salt spray: 48h

■ Air leak: helium leak test ≤ 1×10-3Pa. cm³/s

■ High temperature  high pressure:140 MPa,200℃,10h

In general, glass-metal seals application under extreme high temperature and high pressure environment have certain limitations. Although more and more new materials appear, glass-metal seal are still widely used in various fields as superior materials.