Components of system:
  • Nut;

  • Sleeve;

  • Connectors body having various configurations and O-ring seats on one or more of its ends;

  • NBR O-ring Shore "A" 85÷90 temperature range -20°C +120°C;

The advantages of this type of connection are:

  •  Vacuum and high pressures;

  • No leakages (even to gases);

  • Can withstand high nut torque;

  • Connectors can be equally coupled to metric or inch tubes;

  • Easy to assemble (no special skill required);

  • Can withstand repeated assemblies, replacing only O-ring when and if required by wear and aging.

For this range of fittings, the catalogue codes feature a geometrically shaped O-ring housing which conforms to ISO 8434-3 standard. This particular shape, while using standard fittings, allows for permanent housing within the seat without the need for using any additive substances.


Connectors from FOR S.p.A. are manufactured from drawn barstock (straight parts), or from forgings (elbows, tees, crosses, and flanges).
Our connectors are zinc plated according to ISO 19568, and resist 1.400 hours to red corrosion in test environment according to ISO 9227 NSS, ASTM B 117/97 and DIN 50021 SS.
In order to safeguard integrity and avoid contamination, all parts are supplied with thread protections and other means of preservation.


All connectors requiring seals are supplied with O-ring seals and retaining washers when necessary. See table and illustration.


  • Reduced assembly times. In fact, when assembling connector to tube, there is no need to insert the O-ring into the groove with the addition of grease or else to prevent fall-off when in critical positions. O-ring is already in place;
  • Easier handling. The O-ring being permanently part of connector does not need to be ordered separately nor to be handled as an inventory item;
  • Safer connections. Since it calls for no extra operations at assembly, it reduces the need for higher professional operators.

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