DONIT TESNIT® is your reliable partner and the perfect choice for sealing solutions with a customer-driven approach. Our product range includes different types of materials, enabling you to find your optimum innovative sealing solution.

DONIT TESNIT enjoys an unparalleled reputation among the world’s leading producers of sealing materials. We are a well-established brand name and provide top-quality products that are ISO 9001:2000 certified. We currently offer services in more than 100 countries.

Gaskets for the offshore industry

In addition to being at the forefront of the latest technological trends, DONIT TESNIT boasts a wide product range which, aside from calandered gasket materials, elastomeric products, PTFE, composite and graphite-based sealing products, includes insulation materials and gaskets for industrial applications.

Custom-cut gaskets

With our cutting technology, experience and knowledge, we are able to cut virtually any material. A wide range of cutting equipment provides competitive pricing and high quality regardless of the gasket size or quantity. A large range of presses, special cutting tools, CAM-CAD water jet, as well as a skilled team for the swift production of small quantities, are available.

DONIT TESNIT has the cutting technology, experience and knowledge to produce custom-cut gaskets in virtually any size and material.
Spiral wound gaskets can be used for sealing flange joints, manhole and handhold covers, tube covers, boilers, heat exchangers, pressure vessels, pumps, compressors and valves.
Metal-jacketed gaskets are particularly suitable for sealing flat surfaces of heat exchangers, gas pipes, cast iron flanges, autoclaves and similar equipment.
Metal gaskets with grooved faces have proven to be very effective for sealing flange connections, and are particularly suitable for applications where high temperatures, pressures and fluctuating conditions are encountered.
DONIT TESNIT offers alternative solutions in high-temperature applications.

We offer custom-cut gaskets according to the customer’s own drawing and specification, samples and templates. Cutting tools are made in-house as an integral part of the production unit. There is an extensive catalogue of cutters available.

Heat exchanger gaskets

DONIT TESNIT heat exchanger gaskets come in a broad spectrum of types, including single or double-jacketed, corrugated, plain metal and soft. A large selection of different materials allows heat exchangers to operate at temperatures beyond the capabilities of most soft gasket materials.

Our heat exchanger gaskets are available in a wide range of materials, since they are all custom made. Unique construction provides stability and ensures trouble-free handling and installation.

Spiral wound gaskets

Spiral wound gaskets are special semi-metallic gaskets of great resilience, which are therefore very suitable for applications that have heavy operating conditions. Spiral wound gaskets can be used for sealing flange joints, manhole and handhold covers, tube covers, boilers, heat exchangers, pressure vessels, pumps, compressors and valves. They are used in the petrochemical, pharmaceutical, shipbuilding, food processing and power industry, as well as in nuclear power stations.

Metal-jacketed gaskets

Metal-jacketed gaskets are particularly suitable for sealing flat surfaces of heat exchangers, gas pipes, cast iron flanges, autoclaves and similar equipment. Thanks to their sealing efficiency, metal-jacketed gaskets can stand up to 30% of deviation from the initial thickness, which is very useful in case of irregular or faulty flange rims.

Grooved metallic gaskets

The grooved gasket is the preferred gasket when improved performance at low seating stresses is required. It features excellent anti-blowout properties linked with the reliability of a solid metal-to-metal seal combined with a soft sealing face to provide a tighter joint.

Metal gaskets with grooved faces have proven to be very effective for sealing flange connections, and are particularly suitable for applications where high temperatures, pressures and fluctuating conditions are encountered. Non-metal cover layers ensure that flanges are not damaged, even at extreme loads, and provide excellent sealing properties when supported by the grooved metallic gasket.

The DONIT TESNIT grooved gasket can be used as an alternative for applications associated with jacketed gaskets; for example, heat exchangers, vessels and reactors, and various flanged connections.

Ring joint gaskets

Our metallic ring joint gaskets are manufactured according to the API 6A and ASME B16.20 standards for application at elevated temperatures and pressures. The small sealing area with high contact pressure results in great reliability. The contact surfaces of the gaskets and flange should be carefully processed. Some types of ring-joints are pressure-activated, which means that the higher the pressure, the better the sealability.

Special and custom-made gaskets

With our own technology, knowledge and experience, DONIT TESNIT has the capabilities to meet various customer needs. In close cooperation with customers, we have developed and produced special types of gaskets for various applications. Gaskets can be produced up to the size of 4,000mm in different special types for the most demanding applications in the process industry (for sealing hot gases, etc.)

High-temperature sealing products

With over 60 years of experience in the sealing industry, DONIT TESNIT offers alternative solutions in high-temperature applications. The Donipack range includes braided packing products and die-formed rings; Donitherm comprises high-temperature insulation and technical textiles; and Micalit consists of Mica-based material for high-temperature applications.