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Profile Seal DIN3869 Advantages & Features

Everything you need to know about Profile Seals DIN3869

Axially static soft seals combined with threaded elements are generally called Profile Seals (DIN3869 Seals or Fluid Connector Seals). They are often used as an alternative to an O Ring/Back-up Ring combination.

How do they provide effective sealing?

Profile Ring’s purpose is to stop the medium from leakage, at the same time preventing loss of pressure. The geometry of the Profile Seal prevents twisting during mounting and in the installation housing. Additionally, it minimises the mechanical deformation of the cross-section. In the meantime, the Profile Ring protects from dust and dirt.

Advantages at a glance

  • Possibility to re-fit the seal
  • Minimal mechanical deformation of cross-section – the cross section remains practically constant (even under high stress)
  • No twisting in the groove
  • Easy to manage during fitting
  • Low sensitivity to gap extrusions
  • Excellent sealing behaviour over prolonged periods of time – low leakage
  • No relative movement during pressure cycles – dimensionally stable
  • Nitrile (NBR) Profile Rings are suitable for gas devices and equipment applications in accordance with EN 549 B1/H3 (0°C to +80°C)
  • Viton® (FKM/FPM) & Nitrile (NBR) Profile Rings are suitable for gas devices and equipment applications in accordance with DIN EN 549 E1/H3 (0°C to +150°C)

Profile Seal Materials and its Mechanical and Chemical stability

EPDM – Ethylene Propylene

Colour: Purple

Temperature Range: -45°C to +150°C

Hardness: 80 Shore A

Good Resistance to hot water & steam, silicone oils & greases, many polar solvents, ozone, detergents & potassium hydroxide, washing solutions, many diluted chemicals and acids.

Unsuitable for: mineral oils such as fuels and lubricants.

FKM/FPM – Fluoroelastomer (Viton®)

Colour: Green

Temperature Range: -20°C to +200°C

Hardness: 80 Shore A

Operating Pressure: up to 63 MPa

Good resistance to fuels, aliphatic, aromatic & chlorinated hydrocarbons, many chemicals, mineral oils & greases, weathering, ozone, water (up to +80°C), synthetic greases & oils, engine, transmission and ATF oils (max +150°C), low gas permeability, ageing, low flammability.

Unsuitable for: polar solvents, hot water (above +80°C), steam, glycol-based brake fluids, low molecular organic acids.

NBR – Nitrile

Colour: Black

Temperature Range: -30°c to +100°C

Hardness: 85 Shore A

Operating Pressure: up to 63 MPa

Good resistance to hydraulic oils (H, HL, HLP), water (max +80°C), mineral greases & oils, inflammable hydraulic fluids, HFA, HFB, HFC (up to +60°).

Unsuitable for: polar solvents, non-inflammable hydraulic fluids HFD, glycol-based brake fluids, aromatic & chlorinated hydrocarbons, high aromatic content fluids.


DIN 3869 Profile Rings are used in a broad selection of installations in general industry, general installations are listed below:

  • Pipe fittings
  • Construction machinery
  • Agricultural machinery
  • Excavators
  • Presses
  • Injection moulding machinery
  • Hydraulic valves and fittings
  • Machine tools
  • Dynamic and static application in gas appliances and gas equipment (according to DIN EN549 E1/H3) – NBR and FKM
  • Vacuum applications

Installation Tips

Firstly, avoid damaging the Profile Ring during installation as the sealing performance is not otherwise guaranteed and it might cause leakage. The performance and dependability of Profile Seals are directly related to the installation methods used; therefore, scratches and cavities must be avoided. During installation, make sure that the profile sealing ring is correctly positioned and that the sealing surface is free of dust, dirt and any other foreign particles. Using mounting aid, cover threaded tips. Assembly tools should have no sharp edges and should be made out of soft material. Make sure not to grease the profile rings nor the mounting space. Installation, mounting, and the surface quality must be maintained in compliance with Part 11 of DIN3852. Other available mounting spaces are explained in compliance with ISO11926, ISO9974-3, ISO9974-2, and ISO1179.

If you would like more information about our range of Profile Seals, contact a member of the team.

E & OE. M Barnwell Services endeavour to make sure that all content is correct. Manufacturing partners have provided this information.