# Thermoacoustic stack-section spools: 2 in × 48.65, 58.65 and 68.65 mm (fabrication spec)

> What custom tri-clamp spool holds a thermoacoustic stack as its own section?

- Category: Hardware › Sanitary clamp fittings
- Kind: Hardware
- Basis: Fabrication specs on standard 2 in ferrules (ISO 2852 faces as gen_hardware draws them, BPE tube Ø50.8 × 1.65); length = stack + ambient exchanger 10 + end spacer 9.8 + Type B lip 0.55 − 1.7 (the stack stands 1.7 into the hot joint's flat ring)
- Page: https://xemstudio.com/objects/thermoacoustic-stack-section-spools/ · JSON: https://xemstudio.com/api/geometry?object=thermoacoustic-stack-section-spools · Plain text: https://xemstudio.com/objects/thermoacoustic-stack-section-spools/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 plain 2 in clamp × clamp spool, ordered from a sanitary fabricator to length, that makes the stack its own section: the stack stands on the hot exchanger in the section below, through the hot joint's flat ring; the ambient exchanger sits on the stack; an 8.4 spacer runs from the exchanger to the Type B gasket lip at the top face. Nothing is welded inside.
- The length is set so the column fits exactly: stack + 10 + 9.8 + 0.55 − 1.7. The ambient exchanger then sits 10.35–20.35 below the top face, so the 14 mm water jacket clamps over it at 9.35 mm from the face, clear of the joint's clamp.
- Spec line: '2 in × L mm clamp × clamp spool, tube Ø50.8 × 1.65, two standard 2 in ferrules'. The lower end runs at the hot exchanger's temperature: the builder checks the spool, the ring and the clamp at that temperature.

## 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 |
|---|---|---|---|---|
| faces | ISO 2852 2 in, both ends (land Ø56.5–Ø64, rim 2.85, 1.6 recess, 20° back) | J1: flat hot ring + high-pressure clamp; J2: Type B gasket + high-pressure clamp | clamp | all |
| bore | Ø47.5 × face to face | stack, ambient exchanger disc and 8.4 end spacer | slide | all |
| tube outside | Ø50.8 between the ferrule hubs | water jacket and spool hanger bores Ø50.8 | clamp | all |
| length | 48.65 / 58.65 / 68.65 | stack + 10 + 8.4 + 1.95 − 1.7: the column fits to the J2 gasket lip | designed | all |

## Sizes

| spool | face_to_face_mm | stack | stack_mm | ambient_exchanger_mm | end_spacer_mm | jacket_from_lower_face_mm |
|---|---|---|---|---|---|---|
| spool-2in-48.65mm | 48.64999999999999 | stack-spiral-2in-30-g1.0 | 30 | 10.0 | 9.8 | 25.3 |
| spool-2in-58.65mm | 58.64999999999999 | stack-spiral-2in-40-g1.0 | 40 | 10.0 | 9.8 | 35.3 |
| spool-2in-68.65mm | 68.64999999999999 | stack-spiral-2in-50-g1.0 | 50 | 10.0 | 9.8 | 45.3 |

## 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)
- Xem Studio: [tools/gen_ta_modular.py: the section geometry, the network model and every number on these pages](https://xemstudio.com/) — code — CC BY 4.0
- Long Earth Society: [Engine builds](https://longearthsociety.com/engineering/) — web, video — LES site

## Free STEP/STL (3 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/thermoacoustic-stack-section-spools/index.json

- spool-2in-48.65mm: [STEP](https://xemstudio.com/files/hardware/thermoacoustic-stack-section-spools/spool-2in-48.65mm.step) · [STL](https://xemstudio.com/files/hardware/thermoacoustic-stack-section-spools/spool-2in-48.65mm.stl) — 2 in × 48.65 mm clamp × clamp spool, ISO 2852 faces both ends, Ø47.5 bore: the stack section for a 30 mm stack (stack-spiral-2in-30-g1.0), the ambient exchanger and the 9.8 end spacer
- spool-2in-58.65mm: [STEP](https://xemstudio.com/files/hardware/thermoacoustic-stack-section-spools/spool-2in-58.65mm.step) · [STL](https://xemstudio.com/files/hardware/thermoacoustic-stack-section-spools/spool-2in-58.65mm.stl) — 2 in × 58.65 mm clamp × clamp spool, ISO 2852 faces both ends, Ø47.5 bore: the stack section for a 40 mm stack (stack-spiral-2in-40-g1.0), the ambient exchanger and the 9.8 end spacer
- spool-2in-68.65mm: [STEP](https://xemstudio.com/files/hardware/thermoacoustic-stack-section-spools/spool-2in-68.65mm.step) · [STL](https://xemstudio.com/files/hardware/thermoacoustic-stack-section-spools/spool-2in-68.65mm.stl) — 2 in × 68.65 mm clamp × clamp spool, ISO 2852 faces both ends, Ø47.5 bore: the stack section for a 50 mm stack (stack-spiral-2in-50-g1.0), the ambient exchanger and the 9.8 end spacer

## Questions

**Can I order these?**

Yes: plain 2 in tube on two standard ferrules, cut to the length in the table.

**Why three lengths?**

One per stack length on this site (30, 40, 50 mm spiral stacks). A shorter stack gives more power and less efficiency (the modular engine's page compares them).

## Fits with

- [Build list: Modular free-piston thermoacoustic engine, 2 in tri-clamp (stack sections and a clamp-in linear alternator)](https://xemstudio.com/objects/list-ta-modular-free-piston-2in/)
- [Thermoacoustic stack for tri-clamp spools: Ø34.8, Ø47.5 and Ø72.9, honeycomb and spiral](https://xemstudio.com/objects/thermoacoustic-stack/)
- [Thermoacoustic heat exchangers, hot and cold, parallel plate, for 1.5, 2 and 3 in tri-clamp spools](https://xemstudio.com/objects/thermoacoustic-heat-exchanger/)
- [Thermoacoustic bore spacers and liners for 2 in tri-clamp spools: 9.8, 60 and 61.7 mm](https://xemstudio.com/objects/thermoacoustic-bore-spacer/)
- [Thermoacoustic water jacket: 14 mm clamp-on halves for a 2 in tri-clamp tube](https://xemstudio.com/objects/thermoacoustic-water-jacket/)
- [Tri-clamp spools to a custom length (fabrication spec): 2 in × 340.7 and 310.7 mm, ¾ in × 146.7 and 80.4 mm](https://xemstudio.com/objects/tri-clamp-custom-length-spools/)