Straub pipe couplings join plain-end tubes without machining, forming, welding, or a final test process, which increases pipe shop productivity considerably. Selecting a mechanical pipe coupling does have its risks however, given the delicate nature of thin-walled Cunifer which is susceptible to crushing if the coupling applies too great a radial force on the tube.

Emmanuel Straub, a metallurgist with considerable knowledge of spring technology, developed his Metal-Grip pipe coupling to provide a gentle but firm grip on Cunifer tube.

Each of the Straub coupling components has optimum low stress characteristics such as progressive sealing instead of the traditional static compression seal. A carefully balanced sealing rubber volume versus expansion zone cavity within the coupling prevents any risk of rubber over-stressing. This is contained by the axial restraint gripping teeth set at a bite angle to achieve perfect anchoring, collectively exerting minimal radial force or necking risk. Straub pipe coupling bolt torque values are the lowest when compared with other mechanical coupling systems.

It is now possible to join Cunifer tube from o/d 26.7mm to 609. mm mechanically plain end to plain end in minutes with Lloyds type test approval for 20 bar systems offshore and 16 bar shipbuilding Class 2 systems.

MJ Information No: 20750