Energized seals (lim seal) are sealing systems which consist of a jacket in thermoplastics (PTFE, PE, PEEK) and an internal spring in a corrosion-resistant metals (stainless steel, Inconel, Elgiloy ®, Hastelloy®). They are suitable to ensure the seal both in static and in dynamic applications (linear or rotary movement) and are not subject to aging, as instead happens to all the seals made of elastomeric material. When the energized seal is mounted, the spring is compressed and pushes the lips of the jacket against the groove walls, thus ensuring the seal.

LIMA produces energized seals in PTFE, PE and PEEK equipped with a spring made of metal resistant to corrosion.

The spring is a crucial element, because it provides the permanent elasticity of the jacket and compensates for wear, eccentricities and misalignments. The load of the spring may be provided, for example, to generate a very low friction (dynamic applications) or a very high load (cryogenic applications). LIMA manufactures several profiles of energized seals, many of which may also be fitted interchangeably in the same housing.

There are plenty of applications that require the use of energized seals and include: hydraulics, pneumatics and aircraft conditioning, vacuum technologies, drilling systems, laboratory equipment, machinery for the food industry, for dosing systems and filling, compressors, medical instrumentation, pumps, infrared systems, gas turbines, diesel engines, petrochemical plants, couplings and rotary joints, missiles and spacecraft, cryogenic plants, extruders for plastics, turbine engines, valves, control systems fuel, robots, equipment for the production of semiconductors.


The choice of the most suitable material depends from the application criticality. Here are the most popular materials and they features:

Virgin PTFE

Excellent for static and low speed dynamic applications, excellent chemical resistance, available in FDA format, suitable for vacuum applications, food industry machinery, pharmaceutical equipment, cryogenic plants.

Modified PTFE

Excellent for static applications and moderate speed dynamic applications, good resistance to wear and high temperatures, available in FDA format, good creep and extrusion resistance, suitable for cryogenic and high vacuum applications.

PTFE + carbon-graphite

Excellent for dynamic and high temperature applications, good for non-lubricated applications, particularly suitable for contact with water, steam and gases in general.

PTFE + glass + MoS2

Excellent resistance to wear and high temperature, excellent in low friction applications, suitable for applications with light lubrication or dry-running, suitable for contact with water, steam, hydraulic oils, petrochemical products and chemical compounds.

PTFE + bronze + MoS2

Very resistant to wear, suitable for dynamic applications, suitable for contact with hydraulic oils, air and gases in general.

PTFE + carbon fiber

Great for low friction applications, very resistant to wear, ideal for applications with light lubricated dynamic applications and soft surfaces, suitable for contact with chemicals, petrochemicals, water, steam and hydraulic oils.


Excellent resistance to wear and abrasion, ideal for dynamic applications, available in FDA format, suitable for contact with chemicals, air, gas, food and pharmaceutical products.


Excellent heat resistance and excellent mechanical properties, suitable for contact with petrochemicals, air, gas, chemical and hydraulic oils compounds.