# Tri-clamp spool bored and honed: 2 in × 6 in, bore Ø48.00, a power-piston cylinder

> Can a tri-clamp spool be bored and honed as a piston cylinder?

- Category: Hardware › Sanitary clamp fittings
- Kind: Hardware
- Basis: Stock 2 in × 6 in spool (gen_hardware.tc_spool: ISO 2852 faces, Ø50.8 × 1.65 tube) with the bore finished to Ø48.00 over its whole length: the finished part is drawn as its own part
- Page: https://xemstudio.com/objects/tri-clamp-bored-spool/ · JSON: https://xemstudio.com/api/geometry?object=tri-clamp-bored-spool · Plain text: https://xemstudio.com/objects/tri-clamp-bored-spool/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.** 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.

## Notes

- A standard 2 in × 6 in spool with its bore opened from Ø47.5 to Ø48.00 end to end and finished as a running bore. The wall becomes 1.40 mm; the faces are untouched.
- On the free-piston generator the 48.00 bore is the power piston's clearance seal (the piston's 30 mm land runs in it) and the section of the vessel the alternator works through: the stator and coil sit outside the wall, so the vessel stays sealed and no wire passes through it.
- Hoop stress at the relief setting (15 bar gauge): 27.5 MPa. Do not clamp anything over the piston's seal zone: the generator hangs from the cooler spool S3.

## Mating features (exact size; open press / slide / run / socket by your process clearance, leave designed and clamp as drawn)

| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| bore | Ø48.00 × 152.4 | power piston seal land Ø48.00 × 30 (clearance seal) | run | all |
| bore | Ø48.00 | magnet carrier Ø47.0 (0.5 radial gap, no contact) | designed | all |
| faces | ISO 2852 2 in, both ends | high-pressure clamps + half gaskets round leaves B and C | clamp | all |
| tube OD | Ø50.8 | stator pack teeth; hanger above the piston travel only | clamp | all |

## Sizes

| feature | value |
|---|---|
| bore | Ø48.00 × 152.4, running fit for the piston land |
| wall | 1.3999999999999986 |
| faces | ISO 2852, 2 in |

## Where the files are

- ISO (via iTeh sample): [ISO 2852 clamp liners: face profile and flange / groove diameters](https://cdn.standards.iteh.ai/samples/7850/eb49c396488d408c8ced3e2961d76cf3/ISO-2852-1974.pdf) — PDF — standard excerpt; dimensions are facts
- ASME: [BPE Bioprocessing Equipment (tube OD and wall, clamp fittings)](https://www.asme.org/codes-standards/find-codes-standards/bpe-bioprocessing-equipment) — standard — ASME; dimensions are facts (verify at link)
- Long Earth Society: [Engine builds](https://longearthsociety.com/engineering/) — web, video — LES site

## Free STEP/STL (1 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/tri-clamp-bored-spool/index.json

- spool-2in-6in-bored-48.00: [STEP](https://xemstudio.com/files/hardware/tri-clamp-bored-spool/spool-2in-6in-bored-48.00.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-bored-spool/spool-2in-6in-bored-48.00.stl) — 2 in × 6 in (152.4) spool, bore finished to Ø48.00 end to end (wall 1.40); ISO 2852 faces

## Questions

**Why bore it to 48.00?**

The as-made bore of sanitary tube is not a running surface. Opening it to one round, straight, finished diameter gives the piston a clearance seal; 48.00 cleans up the 47.5 nominal bore and leaves a 1.40 wall.

## Fits with

- [Tri-clamp closed-end spool: 2 in × 152.4 mm (6 in) with a welded closed end, the hot end of a pressurised Stirling](https://xemstudio.com/objects/tri-clamp-closed-end-spool/)
- [Free-piston power piston: Ø48 clearance-seal land, 40-magnet carrier, top plate and tube rod](https://xemstudio.com/objects/fpse-power-piston/)
- [Moving-magnet linear alternator stator outside a 2 in tri-clamp spool: laminated two-tooth stator, one coil](https://xemstudio.com/objects/fpse-linear-alternator-stator/)
- [Build list: Free-piston Stirling generator, 2 in tri-clamp (pressurised, linear alternator)](https://xemstudio.com/objects/list-fpse-generator-2in/)