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Tri-clamp closed-end spool: 2 in × 152.4 mm (6 in) with a welded closed end, the hot end of a pressurised Stirling
What is a closed-end tri-clamp spool and how do I order one for a Stirling hot end? · Hardware · basis: Fabrication spec: a standard 2 in ferrule (ISO 2852 face, as the ferrule on this site) on BPE 2 in tube Ø50.8 × 1.65, closed at the far end by a 3 mm welded end; plain outside (heat exchangers clamp on, see the fin sleeve)
Long Earth Society build part. The hot end of my free-piston generator. The engines
Exact dimensions. Every file is drawn at true size with no printing tolerance. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your printer's or process's clearance before making the part. Mating features
- sizes
- 4 in table
Notes
- Drawing to send to a sanitary fabricator: '2 in × 152.4 mm closed-end spool, one 2 in clamp ferrule, tube Ø50.8 × 1.65, closed end 3 mm, 1.5 outside round'. The face is a standard 2 in clamp face; the rest is plain tube.
- On the free-piston generator it is the hot end: the burner fires at its closed end and lower half, and the only joint is at the top, at the regenerator's cold end, so no gasket is near the flame.
- Inside it are the displacer liner, the heater insert, the regenerator screens and the displacer's hot end. The bore is a slide fit for the liner's spokes and the inserts.
- At the generator's relief setting (15 bar gauge) the tube's hoop stress is 23.0 MPa; whether that is acceptable at the hot-end temperature depends on what the spool is made of, which is the builder's check.
Sizes
| feature | value |
|---|---|
| face | ISO 2852, 2 in (Ø64 flange, Ø56.5 groove, 1.6 recess) |
| tube | Ø50.8 × 1.65 (bore Ø47.5) |
| face to outer end | 152.4 |
| closed end | 3.0, 1.5 outer round |
Mating features
Drawn at the exact size. Open press, slide, run and socket features by your process's clearance; leave designed gaps and clamp fits as drawn.
| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| face | ISO 2852 2 in (land Ø56.5–Ø64, rim 2.85, 1.6 recess, 20° back) | high-pressure clamp + half gaskets round the liner rim | clamp | all |
| bore | Ø47.5 × 149.4 to the closed end | liner spokes, heater insert OD, regenerator ring ODs | slide | all |
| tube OD | Ø50.8 (z 2–68.5 and 76.5–82.5 from the closed end) | fin sleeve halves, shroud lids | clamp | all |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| ISO (via iTeh sample) | ISO 2852 clamp liners: face profile and flange / groove diameters | standard excerpt; dimensions are facts | |
| ASME | BPE Bioprocessing Equipment (tube OD and wall, clamp fittings) | standard | ASME; dimensions are facts verify |
| Long Earth Society | Engine builds | web, video | LES site |
Free files
★ Free files 1 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| closed-spool-2in-152.4 | 2 in × 152.4 mm closed-end spool: ISO 2852 ferrule face at the open end, Ø50.8 × 1.65 tube, 3 mm welded closed end with a 1.5 outer round; bore Ø47.5 to the closed end (149.4 deep) | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=tri-clamp-closed-end-spool
How it fits
In these build lists
Free-piston Stirling generator, 2 in tri-clamp…A real free-piston Stirling generator in standard 2 in sanitary fittings: closed…You might also need
Questions
Can I order this from a sanitary fabricator?
Yes: it is a standard 2 in ferrule on standard tube with a welded closed end; the drawing and the one-line spec above are what they need.
Why not a cap and a gasket at the hot end?
A gasket in the flame is the first thing to fail on a pressurised engine; closing the tube in one piece puts the only joint at the cold end.