Hot-end fin sleeve for a 2 in tri-clamp cup: slide-on ring fins, set-screw held — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/tri-clamp-hot-fin-sleeve/  (CC BY 4.0)
Basis: ASME BPE 2 in tube OD Ø50.8 (the sleeve's bore); fin size and pitch are design values from the sealed generator layout; M4 set screws ISO 4026
Catalog version: 2026-10-20

Sizes: see table below
- A separate heat exchanger for the closed hot end of a plain 2 in cup: a sleeve whose bore is exactly the tube's Ø50.8 slides over the closed end, nine Ø80 ring fins catch the flame gas, and three M4 set screws in a band above the fins hold it. The cup stays a plain, standard closed-end spool; the sleeve can be made any way you like.
- On the sealed generator it sits on the cup-2in-150 from 1.5 mm above the outer bottom (clear of the 1.5 mm round) to 7 mm above the top fin, 49.0 mm in all; the fins cover the bottom 43.5 mm, inside the burner shroud, 4 mm from the shroud's wall.
- The fins are Ø80 so that, starting from the sleeve's Ø56.8 hub, they have the same area as Ø76 fins grown straight off the tube.
- It is optional: the engine runs on the bare cup with less power. The set screws line up with three of the shroud's exhaust windows, so they can be reached with the shroud in place.
- Fits: the bore slides on the tube OD (slide fit), the set screws clamp it.

feature  value
bore  Ø50.8 (tube OD)
length  49.0
wall  3.0
fins  9 × Ø80 × 1.5, 5 pitch
set screws  3 × M4, 0 / 120 / 240°
fits  cup-2in-150 (and any 2 in tube)

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- ISO (via iTeh sample): ISO 2852 clamp liners: face profile and flange / groove diameters — PDF — standard excerpt; dimensions are facts — https://cdn.standards.iteh.ai/samples/7850/eb49c396488d408c8ced3e2961d76cf3/ISO-2852-1974.pdf
- ASME: BPE Bioprocessing Equipment (clamp fitting dimensions, tube OD and wall) — standard — ASME; dimensions are facts [verify license at link] — https://www.asme.org/codes-standards/find-codes-standards/bpe-bioprocessing-equipment
- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/tri-clamp-hot-fin-sleeve/index.json
API: https://xemstudio.com/api/geometry?object=tri-clamp-hot-fin-sleeve