Many people feel confused when choosing Tri-Clover/Tri-Clamp sanitary clamp fittings and clamps, and if you may be one of them don't worry, you are not alone! Even experienced users make mistakes! Here is how sanitary clamp sizing works:

- The most common type of sanitary clamp end connections are commonly known as "Tri-Clover," a brand and registered trademark of Alfa-Laval/Tri-Clover, the major manufacturer of these types of connections for over 50 years, and they are also known as "Tri-Clamp," a registered trademark of Ladish Co. (previous owner of Tri-Clover fittings and its brand). Tri-clamp was originally used to describe the Tri-Clover 3-segment clamps, but the name "tri-clamp" has become a common way of referring to these type clamps. You can click this link that will show the sanitary Tri-Clover and Tri-Clamp type fittings and related items we currently have for sale in our eBay Store

- Tri-Clamp fitting (and clamp) sizes are named after the TUBE OD size that they are used for. For example, a 1/2" tri-clamp fitting has a 1/2" 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.

- 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).

- To complicate matters, the flange OD of the 1/2" and 3/4" tri-clamp end flanges is almost exactly 1" OD (actually 0.984") making many people think that those are 1" tri-clamp size, and the 1"and 1½" tri-clamp end flange OD is, as we said, almost exactly 2" OD (actually 1.984") making many people think that those are 2" tri-clamp size. Below is a chart with the nominal tri-clamp fitting size and the corresponding END FLANGE OD SIZE:

-- 1/2" nominal size (tube OD) fittings - 0.984" ferrule face (end flange) OD
-- 3/4" nominal size (tube OD) fittings - 0.984" ferrule face (end flange) OD
-- 1" nominal size (tube OD) fittings - 1.984" ferrule face (end flange) OD
-- 1-1/2" nominal size (tube OD) fittings - 1.984" ferrule face (end flange) OD
-- 2" nominal size (tube OD) fittings - 2.516" ferrule face (end flange) OD
-- 2-1/2" nominal size (tube OD) fittings - 3.047" ferrule face (end flange) OD
-- 3" nominal size (tube OD) fittings - 3.579" ferrule face (end flange) OD
-- 4" nominal size (tube OD) fittings - 4.682" ferrule face (end flange) OD

In our eBay store we try to be as clear as possible when stating the sizes of the sanitary clamps we sell. You may click on the link to see the sanitary tri-clamp type clamps (and gaskets) we currently have for sale in our eBay Store.

- Also, some fitting sizes share the SAME CLAMP SIZE. The end flange OD of the 1/2" and the 3/4" tri-clamp fittings is THE SAME, therefore the SAME clamp will fit BOTH 1/2" and 3/4" tri-clamp size fittings. The same holds for 1" and 1-1/2" tri-clamp fittings where the flange OD is the SAME for BOTH the 1" and 1-1/2" tri-clamps end flanges and they use the SAME clamp size.

- HOWEVER, even though the 1/2" and the 3/4" share the same clamp size, and so do the 1" and 1-1/2" tri-clamp fittings, and mechanically it is perfectly fine to match a 1/2" tri-clamp end to a 3/4" tri-clamp end and the same for the 1" and the 1-1/2" ends, a user must know if it is OK in THEIR appication to mix the different size fittings. The INTERNAL DIAMETER (ID) of the 1/2" and 3/4" fittings is DIFFERENT and the same goes for the 1" and 1-1/2". This could create problems with flow capacity, drainability, and cleanability of a system if the fitting sizes are mixed, and yet mixing and matching may be OK and even be a money saver for certain applications. The user must decide.

- Tri-clamps come in two main types, 2-segment and 3-segment. The 1/2"-3/4" size clamps ONLY come in 2-segment type. The 1"-1½" and higher size clamps come in 2-segment, which are usually less expensive than the 3-segment type, and in 3-segment which are more expensive and are considered as "heavy duty" though they may or may not be rated for higher pressure. The 3-segment type are a bit easier to install in tight spaces, particularly in the larger sizes. It's up to the end user to choose the type they prefer, and most people choose 2-segment clamps as suitable and cost-effective for most applications.

Hope this makes things clearer for sanitary clamp users.