{
 "version": "2026-10-20",
 "license": "Dimension sheets are written by Xem Studio from the cited sources and are free to use (CC BY 4.0, attribute 'Xem Studio'). Linked files belong to their publishers under the license shown; Xem Studio does not host them. 'license_verified: false' means the license shown is from memory or the publisher's page as last read and should be confirmed at the link before commercial use.",
 "slug": "tri-clamp-volume-filler",
 "name": "Tri-clamp volume fillers: 2 in tee-run plugs and annular sleeves",
 "kind": "hardware",
 "category": "Hardware",
 "group": "Stirling & thermoacoustic",
 "year": null,
 "question": "How do I reduce dead volume in a tri-clamp Stirling engine?",
 "tags": [
  "filler",
  "dead volume",
  "plug",
  "sleeve",
  "tri-clamp",
  "stirling",
  "long earth society"
 ],
 "aliases": [
  "stirling dead volume",
  "reduce dead volume stirling",
  "tri clamp filler plug",
  "stirling volume filler",
  "annular gap heater"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": true,
 "free_files": 4,
 "url": "https://xemstudio.com/objects/tri-clamp-volume-filler/",
 "sheet_txt": "https://xemstudio.com/objects/tri-clamp-volume-filler/sheet.txt",
 "sheet": {
  "basis": "ASME BPE 2 in bore (Ø47.5); ISO 2852 Type B lip reach (2.8 from the joint plane, 1.95 past the face); passage and gap sizes are design values",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Every cubic centimetre of gas that is not swept and not in a heat exchanger lowers the pressure swing. These plugs fill the parts of the fittings where the gas does no work and leave a defined path through them.",
   "Tee-run plugs fill the 177.8 mm run of a 2 in tee between the two gasket lips. The blind plug (173.9 long) has a Ø16 passage from one end to the centre and out to the branch; the half beyond the branch is solid, so a capped run end holds no gas. The rod plug has a Ø12 passage end to end so a Ø3 displacer rod passes through it.",
   "Annular sleeves fill a spool with a 1.0 mm gas gap along the tube wall: the core is Ø45.5, three 3 mm ribs touch the bore. On the hot leg the gap is the heater; on the cold leg the cooler.",
   "All outer diameters are the bore, Ø47.5: a slide fit (Mating features). The gaps and passages are designed."
  ],
  "table": {
   "columns": [
    "file",
    "od_mm",
    "length_mm",
    "passage"
   ],
   "rows": [
    [
     "plug-tee-2in-blind",
     47.5,
     173.9,
     "Ø16 axial to centre + Ø16 radial"
    ],
    [
     "plug-tee-2in-rod-106.55",
     47.5,
     106.55,
     "Ø12 axial through + Ø16 radial"
    ],
    [
     "sleeve-2in-76.2",
     47.5,
     76.2,
     "1.0 annular gap"
    ],
    [
     "sleeve-2in-32",
     47.5,
     32,
     "1.0 annular gap"
    ]
   ]
  }
 },
 "sheet_text": "Tri-clamp volume fillers: 2 in tee-run plugs and annular sleeves — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/tri-clamp-volume-filler/  (CC BY 4.0)\nBasis: ASME BPE 2 in bore (Ø47.5); ISO 2852 Type B lip reach (2.8 from the joint plane, 1.95 past the face); passage and gap sizes are design values\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Every cubic centimetre of gas that is not swept and not in a heat exchanger lowers the pressure swing. These plugs fill the parts of the fittings where the gas does no work and leave a defined path through them.\n- Tee-run plugs fill the 177.8 mm run of a 2 in tee between the two gasket lips. The blind plug (173.9 long) has a Ø16 passage from one end to the centre and out to the branch; the half beyond the branch is solid, so a capped run end holds no gas. The rod plug has a Ø12 passage end to end so a Ø3 displacer rod passes through it.\n- Annular sleeves fill a spool with a 1.0 mm gas gap along the tube wall: the core is Ø45.5, three 3 mm ribs touch the bore. On the hot leg the gap is the heater; on the cold leg the cooler.\n- All outer diameters are the bore, Ø47.5: a slide fit (Mating features). The gaps and passages are designed.\n\nfile  od_mm  length_mm  passage\nplug-tee-2in-blind  47.5  173.9  Ø16 axial to centre + Ø16 radial\nplug-tee-2in-rod-106.55  47.5  106.55  Ø12 axial through + Ø16 radial\nsleeve-2in-76.2  47.5  76.2  1.0 annular gap\nsleeve-2in-32  47.5  32.0  1.0 annular gap\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- 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\n- 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\n- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 4 parts): https://xemstudio.com/files/hardware/tri-clamp-volume-filler/index.json\nAPI: https://xemstudio.com/api/geometry?object=tri-clamp-volume-filler\n",
 "sources": [
  {
   "publisher": "ISO (via iTeh sample)",
   "title": "ISO 2852 clamp liners: face profile and flange / groove diameters",
   "url": "https://cdn.standards.iteh.ai/samples/7850/eb49c396488d408c8ced3e2961d76cf3/ISO-2852-1974.pdf",
   "formats": [
    "PDF"
   ],
   "license": "standard excerpt; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "ASME",
   "title": "BPE Bioprocessing Equipment (clamp fitting dimensions, tube OD and wall)",
   "url": "https://www.asme.org/codes-standards/find-codes-standards/bpe-bioprocessing-equipment",
   "formats": [
    "standard"
   ],
   "license": "ASME; dimensions are facts",
   "license_verified": false,
   "hosted": false
  },
  {
   "publisher": "Long Earth Society",
   "title": "Engine builds",
   "url": "https://longearthsociety.com/engineering/",
   "formats": [
    "web",
    "video"
   ],
   "license": "LES site",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "sanitary-clamp-tees",
  "tri-clamp-spool",
  "sanitary-clamp-spools",
  "list-tri-clamp-elbow-diaphragm-alpha",
  "list-tri-clamp-tee-diaphragm-gamma"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn.",
 "mating": [
  {
   "feature": "plug OD",
   "exact": "Ø47.5",
   "mates": "2 in tube bore",
   "fit": "slide",
   "files": "plug-"
  },
  {
   "feature": "sleeve rib tips",
   "exact": "Ø47.5",
   "mates": "2 in tube bore",
   "fit": "slide",
   "files": "sleeve-"
  },
  {
   "feature": "rod passage",
   "exact": "Ø12",
   "mates": "Ø3 displacer rod (no contact)",
   "fit": "designed",
   "files": "plug-tee-2in-rod-"
  },
  {
   "feature": "flow passages",
   "exact": "Ø16",
   "mates": "gas path to the branch",
   "fit": "designed",
   "files": "plug-"
  },
  {
   "feature": "annular gap",
   "exact": "1.0",
   "mates": "gas gap along the tube wall",
   "fit": "designed",
   "files": "sleeve-"
  }
 ],
 "fit_classes": {
  "press": "stays put: pin, tube, bearing or magnet held by interference. Typical FDM: hole +0.0 to +0.1 mm on diameter.",
  "slide": "assembles by hand and is held by a grub, pinch or clamp: shaft in a hub, rod in a socket, spigot in a bore. Typical FDM: +0.2 mm.",
  "run": "turns or slides in use: pin in a link, rod through a guide. Typical FDM: +0.3 mm.",
  "socket": "large sliding fit: syringe barrel, sleeve, bobbin in a bore. Typical FDM: +0.3 mm.",
  "clamp": "split part that closes on the mating part with screws: make it at size.",
  "designed": "a gap that is part of the design (piston fit option, displacer gap, air gap): do not change."
 },
 "faq": [
  {
   "q": "Why fill the tee run?",
   "a": "A 2 in tee run is 315 mL of gas; with the plug only the Ø16 passage and the gaps remain."
  },
  {
   "q": "Won't a sleeve block the flow?",
   "a": "The 1.0 mm gap all round is 146 mm² of flow area, the same order as the Ø16 passage (201 mm²), and it puts the gas against the heated or cooled wall."
  }
 ],
 "files_license": null,
 "offers": [
  {
   "file": "plug-tee-2in-blind",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-volume-filler/plug-tee-2in-blind.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-volume-filler/plug-tee-2in-blind.stl",
   "note": "2 in tee-run plug Ø47.5 × 173.9: Ø16 passage from one end to the centre, then Ø16 out to the branch; the other half solid"
  },
  {
   "file": "plug-tee-2in-rod-106.55",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-volume-filler/plug-tee-2in-rod-106.55.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-volume-filler/plug-tee-2in-rod-106.55.stl",
   "note": "2 in tee-run plug Ø47.5 × 106.55: Ø12 passage end to end for the displacer rod and the gas, Ø16 out to the branch at 19.60 from the bottom"
  },
  {
   "file": "sleeve-2in-76.2",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-volume-filler/sleeve-2in-76.2.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-volume-filler/sleeve-2in-76.2.stl",
   "note": "2 in annular sleeve Ø45.5 × 76.2 with three 3 mm ribs to Ø47.5: 1.0 mm gas gap along the tube wall (hot spool)"
  },
  {
   "file": "sleeve-2in-32",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "CC BY 4.0 (Xem Studio)",
   "step": "https://xemstudio.com/files/hardware/tri-clamp-volume-filler/sleeve-2in-32.step",
   "stl": "https://xemstudio.com/files/hardware/tri-clamp-volume-filler/sleeve-2in-32.stl",
   "note": "2 in annular sleeve Ø45.5 × 32 with three ribs to Ø47.5: 1.0 mm gas gap (cold spool, above the regenerator)"
  }
 ],
 "markdown": "https://xemstudio.com/objects/tri-clamp-volume-filler/index.md"
}