COCompressor Seals & Terminals

Product Description

On the scale of global warming contribution from refrigerants, carbon dioxide (CO2) has a lesser envirionmental impact than that of "conventional" refrigerants such as CFCs (chlorofluorocarbon) and FCs (fluorocarbon). Because of this, it is increasingly used as a more eco-friendly refrigerant in modern heat pumps for air conditioning systems, refrigerators, and other cooling applications.

However, due to its high vapor pressure, compressors for heat pumps using CO2 as the refrigerant must designed to withstand pressure levels up to ten times higher than those of ordinary compressors.

Compressors are often placed outdoors and are exposed to adverse environmental conditions such as humidity, pressure, vibration, and various chemical substances. At the same time, compressors utilizing CO2 as a refrigerant operate at pressures and temperatures much higher than conventional compressors - up to 180ºC in some instances.

With harsh environmental conditions both within and outside of the compressor, it is crucial that the housing is durable and hermetically sealed to enable safe and reliable performance of the compressor. This is why glass-to-metal sealing (GTMS) technology is the most promising solution for CO2 compressor seals and terminal components: GTMS components consist of materials highly resistance to harsh influences.

Glass-to-metal compressor seals are electrical feedthroughs consisting of a metal base and glass elements, which hermetically seal in metal leads to the base. CO2 compressor seals provide an electrical conduction terminal and at the same time function as a hermetic "cover" for the compressor. They protect the internal components of the compressor from undesirable ambient influences and simultaneously prevent any refrigerant leakage from within. The strong hermetic seal is created and maintained by the compressive force that the eyelet exerts on the glass seal.


Glass-to-metal sealing (GTMS) technology is ideal for demanding applications because of its extremely resistant and durable materials. The special glass composition used has excellent electrical insulation characteristics. The compressive sealing method also provides high material strength and outstanding pressure resistance.

With more than 75 years of experience in GTMS technology, we offer customers optimal material combinations and manufacturing processes for a variety of demanding applications. In addition to a wide range of standard housings, we can also customize our products in close cooperation with our customers.


Compressors for heat pumps using CO2 as a refrigerant represent a specialzed area of application. GTMS compressor seals can be used in all modern CO2 coolant compressors for heat pumps, which are found in refrigerators, air conditioning systems, and water heaters.

Technical Details


CO2 compressor seals utilize glass-to-metal sealing technology to achieve hermeticity for a high quality and reliable component. For more information about our glass-to-metal sealing technology, please visit this page.

Features / Specifications

We provide a wide range of standard seals and work closely with customers to develop customized products.
Base Steel
Lead FE/CR
Glass Soda Barium glass
Finish Nickel plating

Please contact us for more details.

Forms of Supply and Product Packaging

Standard forms of supply are available. Please contact our sales department if you have special requests concerning supply and packaging for CO2 compressor seals and terminal components.


All of our glass-to-metal sealing products are manufactured in our ISO 9001/14001 certified plant, the quality assurance standard of ISO. For more information, please click here.
Exhibitions & Events
Exhibition CIOE - China International Optoelectronic Exposition, Shenzhen, China, 09-01 to 09-03-2021
Exhibition Gastech, Singapore, Singapore, 09-13 to 09-16-2021
Electronic Packaging
SCHOTT North America, Inc.

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Southbridge, MA 01550
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