Tri-Clamp Size Guide | Compare Inch, DIN and ISO Dimensions
Tri-Clamp connections can look similar while having different tube diameters, ferrule dimensions and gasket bores. This guide brings together dimensional charts for identifying existing fittings and comparing the main clamp standards.
HD Process supplies ferrules and seals across these systems, including the inch-based Tri-Clover connections commonly used in New Zealand and Australia.
Understanding Tube, Ferrule and Gasket Dimensions
The nominal fitting size is not the outside diameter of the clamp face. When comparing the drawings and charts, distinguish between:
- Tube outside diameter: the tube dimension at the ferrule weld end.
- Ferrule bore: the internal opening through the fitting.
- Clamp-face outside diameter: the external diameter of the ferrule flange retained by the clamp.
- Gasket dimensions: the bore, outside diameter and sealing profile that must match the connection.
Different tube sizes and standards can share a clamp-face diameter. A clamp fitting around both ferrules does not, by itself, confirm that the bores and gasket are correctly matched.
Inch, DIN, ISO and SMS Dimensional References
The downloadable charts cover the following fitting systems:
- ASME BPE and BS 4825-3 inch-based fittings.
- DIN 32676 dimensional series.
- ISO 1127 and ISO 2037 tube-based dimensions.
- SMS 3008 and SMS 3017 fittings.
- Schedule 5, Schedule 10 and Schedule 40 pipe-based connections.
Use the table for the applicable standard and series. Similar nominal designations across different systems do not necessarily describe interchangeable components.
Ferrule and Gasket Sizing Downloads
The downloads below provide three levels of dimensional reference:
- Ferrule comparison chart, 1 page: a quick comparison of selected sizes across ISO, DIN, ASME BPE and SMS references.
- Ferrule dimensions, 13 pages: expanded tables covering the listed standards and pipe schedules.
- Clamp gasket dimensions, 2 pages: seal dimensions across six ISO, DIN and ASME references.
Contact HD Process for help identifying your clamp connection and matching replacement ferrules or gaskets.
