Gasket installation for tri-clamps is straightforward, but there are a few things you should keep in mind to select the correct seal:

1. Select the correct gasket material based on your application

Depending on the process condition and chemical composition of the fluid, a suitable sealing material must be selected. Otherwise, leakage through the seal or degradation may occur. The table below serves as a guide for selecting a suitable sealing material for a few key applications.





Temperature (°C)


Maintains seal with wide temperature variations. Has an extended service life

Designed to meet critical requirements in

biopharmaceutical, ultra-pure water, WFI (water

for injection), and difficult food and beverage


-20°F to 300°F

-29°C to 149°C


Maintains seal with wide temperature variations. Has extended service life.

Ideal for sanitary

steam pipe connections in extreme temperatures

ranging from -320°F to 550°F.

-320°F to 550°F

-196°C to 288°C


Wide temperature variations may cause leakage at ∆T. 500°F 

Works for longer periods of time in both water and steam applications.

-100°F to 500°F

-73°C to 260°C


Very flexible low temperature. 450°F

In sanitary water systems when PTFE is not

feasible due to severely misaligned fittings,

or if the cost of high-pressure clamps does

not outweigh the benefits of PTFE (extended

service life).

-40°F to 450°F

-40°C to 232°C

FKM Fluoroelastomer or VITON

Acceptable for steam applications. 400°F

Excellent compatibility with strong acids

-30°F to 400°F

-34°C to 204°C

EPDM (peroxide cured)

Low-pressure steam only. 300°F

Chemically, EPDM has good resistance to animal oils, vegetable oils, ozone, strong chemicals, and oxidizing chemicals. Do not use EPDM gaskets for mineral oils, solvents, or aromatic hydrocarbons.

-30°F to 300°F

-34°C to 149°C

Buna (Nitrile)

Not recommended for strong acids and ozone

Chemically, Buna is resistant to many hydrocarbons, fats, oils, greases, hydraulic fluids, and chemicals. Never use Buna Tri-Clamp® Gaskets for Ozone (except PVC blends), ketones, esters, aldehydes, chlorinated hydrocarbons, or nitro hydrocarbons.

-30°F to 200°F

-34°C to 93°C

Gylon blau

Wide temperature range

Food processing



-346°F to 500°F

-210°C to 260°C

Table 1. Gasket Material and applications (Temperatures from this table might vary from each brand)

2. Basic Installatiom guidelines

  • Install the gasket by opening the clamp. Make sure there are no residues on the sealing surfaces if you are changing an older gasket.


Figure 1. Installing the Clamp into the ferrule. (1)

  • Ensure the gasket is the right size for the fitting and center it on the flange. There should be no ridges on the gasket that are not aligned with the fitting geometry and the gasket should align with the Internal Diameter.


Figure 2. Align the ferrule and gasket correctly (2)

  • While the clamp is installed, the gasket should not slide out of position.
  • Align the clamp with the fitting by centering it.

Figure 3. Clamp correctly fit into the center of the system ferrule-gasket (3)

  • When using clamps with multiple bolts, make sure the bolts are tightened uniformly. To prevent the fitting faces from pulling out of alignment, bolts must be tightened in steps.  

3. How to order the clamp and gasket for the rheonics sensor?

  • Let’s order a gasket and clamp for a Rheonics sensor with a tri-clamp process connection with a 1.5" opening, depending on the application a variety of seals could be used. 
  • We can select a gasket from this provider: The order code for this example is CL-CG112Z505-Gy

Technical data



Connection 1:   

Zoll 1 1/2"

Connection 2:  

A 50,5


GYLON blau


1 1/2"


1 1/2"




35,0 ±0,6mm


5 g

Table 2. Datasheet for GYLON blau gasket.

Figure 4. GYLON blau gasket dimensions. (4)

It is generally recommended to choose the one with the same b-dimension as the connecting tube. The inside diameter of a gasket should always be identical to the inside diameter of the pipes so that there’s absolutely no void or intrusion. There are multiple options for 1.5" TCs, so it depends on your needs.

There are local sources for gaskets - online retailers and offline stores that should be consulted by the installers, the example here is only shown as a demonstration. 

4. Selecting the Clamp and Ferrule

To select the correct clamp, the beveled surface on the outside diameter(D) of the ferrule must match the inside diameter(A) of the clamp. Note that the clamp typically determines the pressure rating of the connection. 


Figure 5.Ferrule dimensions (Left) and Clamp dimension (Right) (5)

5. Supplier


6. References

1. [Online][1].

2. [Online] [2].

3. [Online] [3].

4. [Online] [4].

5. [Online] [5].


7. Sources




Pictures, photos and images used are for illustration purposes and do not constitute any warranty or assertions on suitability of use and should not be construed as an explicit or implicit recommendation or endorsement. All illustrations are given proper credit from our source of access and by their use here we do not specify or establish any copyright which belongs and stays unaffected with the existing copyright holder of that material