# Tri-clamp dome lids: 1½ to 12 in, plain or with a port at the crown

> Is there a domed tri-clamp lid with a port on top?

- Category: Hardware › Sanitary clamp fittings
- Kind: Hardware
- Basis: Xem Studio design: an F&D head (crown radius = OD, knuckle 6 %) on a short skirt of the size's tube, with the ISO 2852 face; ports are a ½ NPT Class 3000 half coupling or a 1½ in clamp nozzle
- Page: https://xemstudio.com/objects/tri-clamp-dome-lids/ · JSON: https://xemstudio.com/api/geometry?object=tri-clamp-dome-lids · Plain text: https://xemstudio.com/objects/tri-clamp-dome-lids/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

- Domed lids for the same size of ferrule, vessel or spool. The dome sheds condensate back into the vessel and leaves headspace; the crown port takes an airlock, a blow-off, a thermowell or a spunding valve through a 1½ in clamp or ½ NPT.
- 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 | tube_od_mm | dome_height_mm |
|---|---|---|
| 1½ | 38.1 | 6.5 |
| 2 | 50.8 | 8.6 |
| 3 | 76.2 | 12.9 |
| 4 | 101.6 | 17.2 |
| 6 | 152.4 | 25.8 |
| 8 | 203.2 | 34.4 |
| 10 | 254.0 | 43.0 |
| 12 | 304.8 | 51.6 |

## Where the files are

- ASME: [Flanged and dished (F&D) heads: crown radius = OD, knuckle radius 6 % of OD (BPVC Section VIII torispherical head)](https://www.asme.org/codes-standards/find-codes-standards/bpvc-viii-1-bpvc-section-viii-rules-for-construction-of-pressure-vessels-division-1) — standard — ASME; proportions are facts (verify at link)
- ASME: [B1.20.1 Pipe threads, general purpose (NPT): major diameter, L2, tap drill; B16.11 forged fittings (Class 3000 couplings); B36.10 Sch 40 bore](https://www.asme.org/codes-standards/find-codes-standards/b1-20-1-pipe-threads-general-purpose-inch) — standard — ASME; dimensions are facts (verify at link)
- 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 (16 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/tri-clamp-dome-lids/index.json

- dome-lid-1.5in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-1.5in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-1.5in.stl) — 1½ in dome lid (F&D head), 14.6 from the face to the crown
- dome-lid-2in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-2in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-2in.stl) — 2 in dome lid (F&D head), 16.9 from the face to the crown
- dome-lid-2in-half-npt: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-2in-half-npt.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-2in-half-npt.stl) — 2 in dome lid with a ½ NPT half coupling at the crown (tap-drill bore Ø18.3)
- dome-lid-3in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-3in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-3in.stl) — 3 in dome lid (F&D head), 21.4 from the face to the crown
- dome-lid-3in-half-npt: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-3in-half-npt.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-3in-half-npt.stl) — 3 in dome lid with a ½ NPT half coupling at the crown (tap-drill bore Ø18.3)
- dome-lid-4in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-4in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-4in.stl) — 4 in dome lid (F&D head), 26.2 from the face to the crown
- dome-lid-4in-half-npt: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-4in-half-npt.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-4in-half-npt.stl) — 4 in dome lid with a ½ NPT half coupling at the crown (tap-drill bore Ø18.3)
- dome-lid-4in-1.5in-port: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-4in-1.5in-port.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-4in-1.5in-port.stl) — 4 in dome lid with a 1½ in clamp port at the crown, 51.6 from the face to the port face
- dome-lid-6in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-6in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-6in.stl) — 6 in dome lid (F&D head), 34.3 from the face to the crown
- dome-lid-6in-1.5in-port: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-6in-1.5in-port.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-6in-1.5in-port.stl) — 6 in dome lid with a 1½ in clamp port at the crown, 59.7 from the face to the port face
- dome-lid-8in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-8in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-8in.stl) — 8 in dome lid (F&D head), 42.9 from the face to the crown
- dome-lid-8in-1.5in-port: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-8in-1.5in-port.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-8in-1.5in-port.stl) — 8 in dome lid with a 1½ in clamp port at the crown, 68.3 from the face to the port face
- dome-lid-10in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-10in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-10in.stl) — 10 in dome lid (F&D head), 51.5 from the face to the crown
- dome-lid-10in-1.5in-port: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-10in-1.5in-port.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-10in-1.5in-port.stl) — 10 in dome lid with a 1½ in clamp port at the crown, 76.9 from the face to the port face
- dome-lid-12in: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-12in.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-12in.stl) — 12 in dome lid (F&D head), 60.1 from the face to the crown
- dome-lid-12in-1.5in-port: [STEP](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-12in-1.5in-port.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-dome-lids/dome-lid-12in-1.5in-port.stl) — 12 in dome lid with a 1½ in clamp port at the crown, 85.5 from the face to the port face

## Questions

**What goes in the crown port?**

Anything with a 1½ in clamp (airlock cap, thermowell, blow-off) or a ½ NPT fitting.

## Fits with

- [Tri-clamp vessels with a dished or round welded bottom: 4, 6 and 8 in, 12 to 24 in deep](https://xemstudio.com/objects/tri-clamp-dished-bottom-vessels/)
- [Tri-clamp end caps with ports: NPT, clamp nozzle, hose barb and airlock hole, 1½ to 8 in](https://xemstudio.com/objects/tri-clamp-ported-end-caps/)
- [Tri-clamp thermowells: 1½ and 2 in clamp, 2½ to 12 in insertion, ½ NPT top](https://xemstudio.com/objects/tri-clamp-thermowells/)