Determining tri-clamp Size
The right Tri-Clamp fitting
We notice that there is a lot of confusion about which size Tri-Clamp must be ordered. This distinction is important because the Tri-Clamp flange, which follows a standard, is approximately ½” larger than the tubing and it is the most common point of confusion.
Thus a 1½” Tri-Clamp fitting, have a flange that is 1.984” (almost 2" on a tape measure), and if we go by the flange measurement and order a 2" Tri-clamp to match, we find our newly arrived fitting is about ½” too large.
This can become especially confusing when the Tri-Clamp fitting has no pipe attached to it, as it is the case with adapters. For instance, a 1½” Tri-Clamp to ½” hose barb adapter is not 1½” inches in any dimension, but the Tri-Clamp end fits any other 1½” Tri-Clamp fitting.
Another significant point of confusion comes from the smaller outside diameter (OD) tubing. The ½” and ¾” tubes both share the ¾” Tri Clamp ferrule (0.984" flange), and the same is true for the 1" and 1½” tubes which share the 1½” Tri Clamp ferrule (1.984" flange) - two clamp sizes for 4 different fittings.
How are Tri-Clamp Fittings Measured?
There are two options for finding your sanitary fitting dimensions:
Option A
Measure the outside diameter (OD) of the tube end.
In the Tube End Standards table (page 312) you find the size (and the corresponding standard).
Option B
Measure the Flange Diameter (F) of the flange end when the Tri-Clamp fitting has no pipe attached to it. To determine your size, also note the inside diameter (ID), to find the right standard and size. On the next page you find the table to do so.
| ID ⌀ (mm) | Flange F ⌀ (mm) | ISO(1127) | DIN32676 (Series 2) |
ASME-BPE | SMS(3008) |
|---|---|---|---|---|---|
| 4 | 25 | -- | DIN-DN04 ** | -- | -- |
| 4.57 | 25 | -- | -- | ¼" | -- |
| 6 | 25 | -- | DIN-DN06 ** | -- | -- |
| 7.75 | 25 | -- | -- | ⅜" | -- |
| 8 | 25 | -- | DIN-DN08 ** | -- | -- |
| 10 | 34 | -- | DIN-DN10 ** | -- | -- |
| 9.4 | 25 | -- | -- | ½" | -- |
| 10.3 | 25 | ISO-DN08 | -- | -- | -- |
| 10.3 | 34 | ISO-DN08 * | -- | -- | -- |
| 10.3 | 50.5 | ISO-DN08 * | -- | -- | -- |
| 14 | 25 | ISO-DN10 | -- | -- | -- |
| 14 | 34 | ISO-DN10 * | -- | -- | -- |
| 14 | 50.5 | ISO-DN10 * | -- | -- | -- |
| 16 | 25 | -- | -- | -- | SMS-DN15 |
| 16 | 34 | -- | DIN-DN15 | -- | -- |
| 15.75 | 25 | -- | -- | ¾" | -- |
| 18.1 | 50.5 | ISO-DN15 | -- | -- | -- |
| 18.1 | 34 | ISO-DN15* | -- | -- | -- |
| 20 | 50.5 | -- | -- | -- | SMS-DN20 |
| 20 | 34 | -- | DIN-DN20 | -- | -- |
| 22.6 | 50.5 | -- | -- | -- | SMS-DN25 |
| 22.1 | 50.5 | -- | -- | 1" | -- |
| 22.9 | 50.5 | ISO-DN20 | -- | -- | -- |
| 23.7 | 50.5 | ISO-DN20 * | -- | -- | -- |
| 26 | 50.5 | -- | DIN-DN25 | -- | -- |
| 29.6 | 50.5 | -- | -- | -- | SMS-DN32 |
| 29.7 | 50.5 | ISO-DN25 | -- | -- | -- |
| 30.5 | 50.5 | ISO-DN25 * | -- | -- | -- |
| 31.3 | 50.5 | ISO-DN25 * | -- | -- | -- |
| 32 | 50.5 | -- | DIN-DN32 | -- | -- |
| 35.6 | 50.5 | -- | -- | -- | SMS-DN40 |
| 34.8 | 50.5 | -- | -- | 1½" | -- |
| 38 | 50.5 | -- | DIN-DN40 | -- | -- |
| 38.4 | 50.5 | ISO-DN32 | -- | -- | -- |
| 44.3 | 64 | ISO-DN40 | -- | -- | -- |
| 47.5 | 64 | -- | -- | 2" | -- |
| 48.6 | 64 | -- | -- | -- | SMS-DN50 |
| 50 | 64 | -- | DIN-DN50 | -- | -- |
| 56.3 | 77.5 | ISO-DN50 | -- | -- | -- |
| 60.3 | 77.5 | -- | -- | -- | SMS-DN65 |
| 60.2 | 77.5 | -- | -- | 2½" | -- |
| 66 | 91 | -- | DIN-DN65 | -- | -- |
| 72.9 | 91 | -- | -- | -- | SMS-DN80 |
| 72.1 | 91 | ISO-DN65 | -- | -- | -- |
| 72.9 | 91 | ISO-DN65 * | -- | -- | -- |
| 81 | 106 | -- | DIN-DN80 | -- | -- |
| 84.3 | 106 | ISO-DN80 | -- | -- | -- |
| 97.6 | 119 | -- | -- | -- | SMS-DN100 |
| 97.38 | 119 | -- | -- | 4" | -- |
| 100 | 119 | -- | DIN-DN100 | -- | -- |
| 109.7 | 130 | ISO-DN100 | -- | -- | -- |
| 125 | 155 | -- | DIN-DN125 | -- | -- |
| 135.1 | 155 | ISO-DN125 | -- | -- | -- |
| 146.86 | 167 | -- | -- | 6" | -- |
| 150 | 183 | -- | DIN-DN150 | -- | -- |
| 163.1 | 183 | ISO-DN150 | -- | -- | -- |
** DIN 32676 Series 1
We utilize cookies to ensure you have the best possible experience while visiting our website.