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 — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/tri-clamp-custom-length-spools/  (CC BY 4.0)
Basis: ASME BPE tube (2 in: Ø50.8 × 1.65; ¾ in: Ø19.05 × 1.65) and ISO 2852 ferrule faces exactly as the standard spools on this site (gen_sanitary.spool); lengths from the engine layouts in tools/gen_ta_power.py
Catalog version: 2026-10-20

Sizes: see table below
- Plain spools: standard tube with a standard ferrule on each end, nothing else, cut to the stated face-to-face length. Any sanitary fabricator makes them from this drawing; a spool is the cheapest custom tri-clamp part there is.
- 2 in × 340.7: the core of each unit of the double-acting ring engine (two ambient exchangers, 100 mm regenerator, hot exchanger, 180 mm buffer tube, two 8.4 spacers between the gasket lips). 2 in × 310.7: the twin-piston engine's core.
- ¾ in × 146.7 and × 80.4: the riser pieces of each engine's ¾ in feedback line, between the instrument tee and cross.
- Fits: the faces are clamp faces; the 2 in bore Ø47.5 takes the exchanger inserts, screens and liners as a slide fit (Mating features).

file  size_in  face_to_face_mm  tube_mm  use
spool-2in-340.7mm  2  340.7  50.8 × 1.65  ring core
spool-2in-310.7mm  2  310.7  50.8 × 1.65  twin core
spool-0.75in-146.7mm  0.75  146.7  19.05 × 1.65  ring riser
spool-0.75in-80.4mm  0.75  80.4  19.05 × 1.65  twin riser

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- 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
- 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
- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 4 parts): https://xemstudio.com/files/hardware/tri-clamp-custom-length-spools/index.json
API: https://xemstudio.com/api/geometry?object=tri-clamp-custom-length-spools