Help with Tri-clamp Sizing

Posted: 4th April 2014

Many pharmaceutical production engineers feel confused when choosing the right size of tri-clamp sanitary fittings, and if you are one of them don't worry, you are not alone! Even experienced engineers make mistakes! Here is how tri-clamp sizing works.

Tri-clamp fittings, and clamp sizes are referenced from the tube OD (outside diameter) size that they are used for. For example, a ½" tri-clamp fitting has a ½" OD on the tube part of the body of the fitting, a 1" fitting has a 1" OD on the tube part of the fitting, etc See fig 1.

The flange end sizes of the tri-clamp fittings are named, of course, to match the tri-clamp fitting sizes, however (and this is the major point of confusion for anyone purchasing tri-clamp fittings) the OD size of the flange ends (also known as the "ferrule face") is NOT the same as and must NOT be confused with the fitting size. For example, 1" size tri-clamp fitting has approximately a 2" OD flange (ferrule face). See fig 2.


Fig 1.   Fig 2.
Tri-Clamp size ½ inch
Tri-Clamp size 1 inch
Tri-Clamp
Tri-Clamp size 1 inch

For more information call 0121 661 6548 and our knowledgable sales team will be happy to help you further.