Union L Couplings

  • For tubes, which repeatedly need to be opened for cleaning and checking, this coupling brings remarkable advantages. Opening and assembly are fast and easy – the coupling has only two or three bolts.
  • Union L-coupling is small and light. It is easy to assemble in tight spaces. The bolts are perpendicular to the tube, hence e.g. the surrounding walls don’t block the tightening of the bolts.
  • Union L is a secure coupling, because the force is affecting to the clamps and not to the bolts. The use of the coupling will not create stresses to the tube. Thanks to the design of the coupling, it’s not possible to force two tubes to unite, if their central lines do not match.
  • Union L contains following items: two equal flanges, that will be welded into the tubes, the gasket and two clamps. When tightening the clamps, the gasket surfaces are pressed against each other. The gasket has to be in it’s groove. Hence a rigid, with conventional flange joint comparable joint is achieved.
  • O ring made of Nitrile, Viton or Teflon is used as gasket, the used material is depending on temperature and the substance in the tube.

Resistance of gaskets in different substances

Nitrile rubber Viton Teflon
Dilutes acids 2 1 1
Concentrated acids 1 1
Aliphatic hydrocarbons (benzene) 2 2 1
Aromatic hydrocarbons (benzene, toluene) 1 1
Chlorinated hydrocarbons (tri, per, tetra) 1 1
Solvents (acetone) 1
Hydraulic oil on mineral oil base 100°C 150°C 260°C
Hydraulic oil on ester base 1 1
Animal and vegetable fats (linseed oil, olive oil) 1 1 1
Water (steam) 80°C 100°C 260°C
Dry heat 100°C 200°C 260°C
Cold -35°C -20°C -80°C

Resistance: 1 = very good, 2 = good, 3 = acceptable, – = poor

Teflon to be used at a constant temperature level, max. +260 C.

Variations might cause leakage due to the different heat expansion of Teflon and steel.