Crankcase insert for a 2 in tri-clamp cross: displacer-rod guide, crank chamber and run filler — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/tri-clamp-cross-crankcase-insert/  (CC BY 4.0)
Basis: ASME BPE 2 in bore Ø47.5; ISO 2852 Type B lip (Ø45.3, 2.8 from the joint plane); slot, chamber and gap sizes are design values from the crank and con-rods
Catalog version: 2026-10-20

Sizes: see table below
- One piece that fills the run of a 2 in cross with the working gas still free to move. It drops in from the top, stands on the lower gasket's lip and passes the lip with a Ø45.3 spigot that ends level with the lip's lower face.
- Lower run: a Ø3 bore 31.55 mm long is the displacer-rod guide (running fit). Above it a column for the displacer's rod clevis and a slab for its con-rod; two Ø8 passages carry the gas from under the insert to the crank chamber; a Ø18 pocket at the bottom takes the displacer cap's boss at the top of its stroke.
- Middle: a Ø29 chamber straight through along the branch axis; the two branch plugs' noses fill its ends up to the crank. Upper run: slab and column for the diaphragm con-rod and clevis, a Ø22 pocket for the centre disc and nuts, and a cone that stays 1 mm under the membrane at full inward travel.
- Fits: Ø47.5 slide in the bore; spigot touches the lip's Ø45.3; Ø3 guide run on the rod. Chamber, slots and the gap under the membrane are designed.

feature  value
outside  Ø47.5, -86.95 to 88.25 from the cross centre
spigot  Ø45.3 to -92.55
guide  Ø3 × 31.55
crank chamber  Ø29 along X
gas passages  2 × Ø8
gap under the membrane  1 at ±6 travel

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
- 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-cross-crankcase-insert/index.json
API: https://xemstudio.com/api/geometry?object=tri-clamp-cross-crankcase-insert