# Tri-clamp orifice-plate gaskets: 1½ to 4 in, holes at 25, 50 and 75 % of the bore

> What is a tri-clamp orifice plate gasket?

- Category: Hardware › Sanitary clamp fittings
- Kind: Hardware
- Basis: Xem Studio design: the ISO 2852 Type B gasket with a 1.5 mm plate across the bore and one centre hole
- Page: https://xemstudio.com/objects/tri-clamp-orifice-plate-gaskets/ · JSON: https://xemstudio.com/api/geometry?object=tri-clamp-orifice-plate-gaskets · Plain text: https://xemstudio.com/objects/tri-clamp-orifice-plate-gaskets/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- Restricts flow at a joint: slows a drain, sets a flow for a chiller or a sparge, or makes a crude flow meter. Hole sizes are 25, 50 and 75 % of the bore.
- Every clamp face is the ISO 2852 profile used across this site: 2.85 mm rim, flat face with the gasket groove (K 1.6 deep, R3 1.2 bottom, 23° walls, P2 0.8 edges) on C2, 20° back cone. Flange C3 / groove C2 / tube OD × wall, mm: ½–¾ in 25.0 / 20.4 (derived) / 12.7–19.05 × 1.65; 1–1½ in 50.5 / 43.5 / 25.4–38.1 × 1.65; 2 in 64.0 / 56.5 / 50.8 × 1.65; 2½ in 77.5 / 70.5 / 63.5 × 1.65; 3 in 91.0 / 83.5 / 76.2 × 1.65; 4 in 119.0 / 110.0 / 101.6 × 2.11; 6 in 166.9 (6.570 in) / 156.5 / 152.4 × 2.77; 8 in 217.7 (8.570 in) / 207.0 / 203.2 × 2.77; 10 in 268.5 / 261.0 / 254.0 × 3.40; 12 in 319.3 / 311.8 / 304.8 × 3.40.

## Sizes

| size_in | bore_mm | hole_mm |
|---|---|---|
| 1.5 | 34.8 | 8.7 |
| 1.5 | 34.8 | 17.4 |
| 1.5 | 34.8 | 26.1 |
| 2 | 47.5 | 11.9 |
| 2 | 47.5 | 23.8 |
| 2 | 47.5 | 35.6 |
| 3 | 72.9 | 18.2 |
| 3 | 72.9 | 36.5 |
| 3 | 72.9 | 54.7 |
| 4 | 97.38 | 24.3 |
| 4 | 97.38 | 48.7 |
| 4 | 97.38 | 73.0 |

## Where the files are

- GW Kent: [Tri-clamp fittings guide: tube OD, flange OD and ID per size to 12 in; solid cap thickness](https://www.gwkent.com/triclamp-guide) — web — publisher's guide; dimensions cited
- Rubber Fab: [Tri-Clamp gasket dimensional chart: gasket ID, OD and bead diameter per size (2 in bead 2.22 in / 56.50 mm, 1.5 in 1.71 / 43.50, 3 in 3.29 / 83.50)](https://shop.andersonprocess.com/media/assets/product/documents/rubber-fab-tri-clamp-dimensions.pdf) — PDF — maker chart; dimensions are facts (verify at link)

## Free STEP/STL (12 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/index.json

- orifice-gasket-1.5in-8.7mm: [STEP](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-1.5in-8.7mm.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-1.5in-8.7mm.stl) — 1.5 in orifice-plate gasket: 1.5 plate, Ø8.7 hole (25 % of the bore)
- orifice-gasket-1.5in-17.4mm: [STEP](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-1.5in-17.4mm.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-1.5in-17.4mm.stl) — 1.5 in orifice-plate gasket: 1.5 plate, Ø17.4 hole (50 % of the bore)
- orifice-gasket-1.5in-26.1mm: [STEP](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-1.5in-26.1mm.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-1.5in-26.1mm.stl) — 1.5 in orifice-plate gasket: 1.5 plate, Ø26.1 hole (75 % of the bore)
- orifice-gasket-2in-11.9mm: [STEP](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-2in-11.9mm.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-2in-11.9mm.stl) — 2 in orifice-plate gasket: 1.5 plate, Ø11.9 hole (25 % of the bore)
- orifice-gasket-2in-23.8mm: [STEP](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-2in-23.8mm.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-2in-23.8mm.stl) — 2 in orifice-plate gasket: 1.5 plate, Ø23.8 hole (50 % of the bore)
- orifice-gasket-2in-35.6mm: [STEP](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-2in-35.6mm.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-2in-35.6mm.stl) — 2 in orifice-plate gasket: 1.5 plate, Ø35.6 hole (75 % of the bore)
- orifice-gasket-3in-18.2mm: [STEP](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-3in-18.2mm.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-3in-18.2mm.stl) — 3 in orifice-plate gasket: 1.5 plate, Ø18.2 hole (25 % of the bore)
- orifice-gasket-3in-36.5mm: [STEP](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-3in-36.5mm.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-3in-36.5mm.stl) — 3 in orifice-plate gasket: 1.5 plate, Ø36.5 hole (50 % of the bore)
- orifice-gasket-3in-54.7mm: [STEP](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-3in-54.7mm.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-3in-54.7mm.stl) — 3 in orifice-plate gasket: 1.5 plate, Ø54.7 hole (75 % of the bore)
- orifice-gasket-4in-24.3mm: [STEP](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-4in-24.3mm.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-4in-24.3mm.stl) — 4 in orifice-plate gasket: 1.5 plate, Ø24.3 hole (25 % of the bore)
- orifice-gasket-4in-48.7mm: [STEP](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-4in-48.7mm.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-4in-48.7mm.stl) — 4 in orifice-plate gasket: 1.5 plate, Ø48.7 hole (50 % of the bore)
- orifice-gasket-4in-73mm: [STEP](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-4in-73mm.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-orifice-plate-gaskets/orifice-gasket-4in-73mm.stl) — 4 in orifice-plate gasket: 1.5 plate, Ø73 hole (75 % of the bore)

## Questions

**Which hole size?**

Start at 50 % of the bore; the flow through an orifice goes roughly with the hole area.

## Fits with

- [Tri-clamp screen gaskets: 1½ to 4 in, Ø2 and Ø3 mm perforated plate](https://xemstudio.com/objects/tri-clamp-screen-gaskets/)