# Branch plugs for a 2 in tri-clamp cross crankcase

> How do I fill the side branch of a 2 inch tri-clamp cross?

- Category: Hardware › Stirling & thermoacoustic
- Kind: Hardware
- Basis: ASME BPE 2 in bore Ø47.5; ISO 2852 Type B lip Ø45.3 and cap recess 1.6; the saddle is the Ø47.5 run bore
- Page: https://xemstudio.com/objects/tri-clamp-cross-branch-plug/ · JSON: https://xemstudio.com/api/geometry?object=tri-clamp-cross-branch-plug · Plain text: https://xemstudio.com/objects/tri-clamp-cross-branch-plug/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses

**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 branch plug fills a 2 in cross branch from the crank chamber to the cap: Ø47.5 up to the gasket lip, then Ø45.3 through the lip to the cap's recess floor, so no gas is left in the joint.
- Its inner end is cut by the Ø47.5 run, so it meets the crankcase insert face to face, and a Ø29 nose runs on into the insert's crank chamber up to the crank. The blind plug goes on the end-cap side; the bored one (Ø16) takes the bearing cap's spigot.
- Fits: Ø47.5 slide in the bore; Ø45.3 touches the lip; the Ø16 bore is a slide fit on the spigot.

## 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 |
|---|---|---|---|---|
| outside | Ø47.5 | 2 in cross branch bore | slide | all |
| lip spigot | Ø45.3 to the cap recess floor | Type B gasket lip (ID 45.3) and the cap | slide | all |
| saddle | Ø47.5 cylinder across the plug | crankcase insert outside | designed | all |
| nose | Ø29 | crank chamber of the insert | slide | all |
| spigot bore | Ø16 | bearing-cap spigot | slide | branch-plug-2in-bore16* |
| hub pockets | Ø22 × 4 and Ø12 × 10 | hub web and hub turning in them | designed | branch-plug-2in-bore16* |

## Sizes

| file | nose_end_mm | bore |
|---|---|---|
| branch-plug-2in-blind | 15.5 | none |
| branch-plug-2in-bore16 | 13.5 | Ø16 |

## 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 (clamp fitting dimensions, tube OD and wall)](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 (2 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/tri-clamp-cross-branch-plug/index.json

- branch-plug-2in-blind: [STEP](https://xemstudio.com/files/hardware/tri-clamp-cross-branch-plug/branch-plug-2in-blind.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-cross-branch-plug/branch-plug-2in-blind.stl) — 2 in cross branch plug: Ø47.5 from the saddle to 86.95, Ø45.3 to 92.20 (from the cross centre), Ø29 nose to 15.5; end-cap side
- branch-plug-2in-bore16: [STEP](https://xemstudio.com/files/hardware/tri-clamp-cross-branch-plug/branch-plug-2in-bore16.step) · [STL](https://xemstudio.com/files/hardware/tri-clamp-cross-branch-plug/branch-plug-2in-bore16.stl) — 2 in cross branch plug as the blind one with the nose to 13.5 and a Ø16 bore for the bearing cap's spigot

## Questions

**Why the saddle end?**

The insert in the run is a Ø47.5 cylinder; a flat end would leave about 6 mL of gas between them on each side.

## Fits with

- [Crankcase insert for a 2 in tri-clamp cross: displacer-rod guide, crank chamber and run filler](https://xemstudio.com/objects/tri-clamp-cross-crankcase-insert/)
- [Tri-clamp bearing cap: 2 in cap with a long Ø3 shaft bore and two 623 seats](https://xemstudio.com/objects/tri-clamp-bearing-cap/)
- [Sanitary clamp crosses (9MP): ½ to 4 in](https://xemstudio.com/objects/sanitary-clamp-crosses/)
- [Build list: Tri-clamp cross diaphragm gamma, 2 in](https://xemstudio.com/objects/list-tri-clamp-cross-diaphragm-gamma/)