Tri Clamp process connection

Tri Clamp (sometimes referred as Tri Clover) is a commonly used sanitary fitting with a clamp end ferrule, size (1", 2", DN20, DN40, etc) of a Tri Clamp is determined by the tubing outer diameter and the norm used (USA uses ASTM while Europe and Asia uses mostly DIN/ISO norm). The components of the Tri Clamp connection and commonly available materials are:

Clamp ferrules (material: 304/304L, 316/316L)

Gasket (material: FKM, Viton, FPM, etc)

Clamp (material: 304/304L, 316/316L)

Tri Clamp adapter design considerations

To connect the inline viscometer SRV or inline density and viscosity meter SRD using tri-clamp connections is easy. We recommend that you design the adapter keeping the following in mind:

  • Avoid stagnant fluid zones around the sensing element 
  • Ensure best fluid transport across the sensing element - the better the transport, the better the measurement tracks the actual changes in the fluid
  • Avoid deposits on the sensor, but if you have some possibility of deposit then place the sensor in a way that the sensing element sees least deposits and any sedimentation only affects the neck of the sensor.
  • However, if there are any deposits, the sensor detects and can warn customers (digital communication needed)
  • Remember: Sensor measures what is around it

Special consideration for real world applications aka non-Newtonian fluids

  • Non-Newtonian fluids make up 99% of applications and have a strong dependence of viscosity on shear rate. 

  • Shear rate is affected by the flow conditions imposed on the fluids by the pumping and the piping. 
  • If the fluid has very different flow rates across the sensor and is not consistent then the measurements will also change as the fluid flow rate changes across the sensor. 

Designing your flow-through adapter/cell/spool in a way that makes the flow regime consistent across the sensor is important to get stable, consistent readings from the sensor in your application.

Rheonics Tri Clamp adapter recommendation


The design we propose for the adapter takes the points mentioned above into consideration. The sensor is long enough that you can introduce the sensing element in a flow through section by tilting the sensor. For larger ID pipes (>2", >DN50), you can install the sensor vertically while keeping the points mentioned above in consideration.

The example below shows a 2" pipe. The design has the following advantages: 

  • ensuring complete sensor sensing element is in the flow
  • make it easy to create hygienic connections
  • removable to check and clean sensors when and if needed






Computational fluid dynamics (CFD) simulation of flow field around the sensing element

CFD uses numerical analysis to analyze and solve fluid flow problems. It is commonly used in fluid mechanics to solve and visualize flow field around structures. We have used CFD to analyze the flow velocity around the sensing element and used it to minimize low velocity flow around the sensing element.


CFD results analysis:

  • BLUE shows low flow velocity regions which is minimized around the sensing element 
  • BLUE areas around neck of sensor shows low fluid velocity in that region but it is ok as neck is not contributing to the measurement.
  • We also recommend orienting the sensor so it faces the oncoming flow, this ensures better cleaning of the probe by having higher flow velocity of the fluid around it, however it is generally not an issue if it faces away from flow
  • there should be good gap between the sensing element end and wall of pipe to ensure large solids in flow (if present) does not get stuck in between. 


Download drawing for a 2" Tri Clamp pipe adapter.

Download 3D STEP file for a Tri Clamp SRV - viscometer

Download 3D STEP file for a Tri Clamp SRD - density and viscosity meter

Download 3D STEP file for a 2" Tri Clamp flow through adapter with SRV


How to select the correct Seal Ring for Tri-Clamp adapters?