Tri-clamp port cap: 2 in, four 1/8 NPT ports for a fill valve, a gauge, a relief valve and an electrical pass-through — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/tri-clamp-port-cap/  (CC BY 4.0)
Basis: ISO 2852 face and 20° back exactly as the flat end cap; 1/8-27 NPT (ASME B1.20.1): major Ø10.29, hand-tight engagement L1 4.1, effective thread L2 6.7, tap drill Ø8.6 (as on this site's NPT thread envelope page)
Catalog version: 2026-10-20

Sizes: see table below
- The flat end cap's profile with a Ø46.7 neck to 18 mm. Four 1/8 NPT ports on Ø24, 90° apart, each drawn as its tap drill, Ø8.6 × 10 deep from the top (the thread as the tap-drill bore, the convention of the thread envelopes on this site), then a passage on into the vessel.
- Three ports for the fill valve, the pressure gauge and the pressure relief valve (Ø3 passages). The fourth takes a sealed electrical pass-through with a 1/8 NPT male thread, for the generator's three leads; its passage is Ø6 so the leads reach it from inside.
- On the sealed generator this cap sits on the motor-mount plate at the top of the cross, so all four see the crankcase, which follows the working space's mean pressure through the bleed.
- Design charge 2 bar gauge. That pressure pushes a cap off its joint with 354 N over the Ø47.5 bore, 501 N if it acts out to the gasket bead (Ø56.5); at a 3 bar relief setting 532–752 N. Every clamp, fitting, pass-through and cap on the vessel must be rated above the relief setting; I set the relief valve no higher than the lowest of those ratings.

feature  value
face  ISO 2852, as the 2 in flat end cap
height  18.0
ports  4 × 1/8-27 NPT on Ø24, 90° apart
tap drill  Ø8.6 × 10
thread (B1.20.1)  Ø10.29 major, L1 4.1, L2 6.7
passages  Ø6 (pass-through), 3 × Ø3
end force, 2 bar g  354–501 N
end force, 3 bar g  532–752 N

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- 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
- 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
- ASME: ASME B1.20.1 Pipe Threads, General Purpose, Inch (NPT): 1/8-27 major Ø10.29, hand-tight engagement L1 4.1, effective thread L2 6.7; tap drill Ø8.6 as on this site's NPT thread envelopes — standard — ASME; dimensions are facts [verify license at link] — https://www.asme.org/codes-standards/find-codes-standards/b1-20-1-pipe-threads-general-purpose-inch
- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/tri-clamp-port-cap/index.json
API: https://xemstudio.com/api/geometry?object=tri-clamp-port-cap