{
 "version": "2026-10-20",
 "license": "Dimension sheets: CC BY 4.0. Standard and published-size files: CC BY 4.0. Xem Studio's own designs (files_license = Xem Studio Design License): free to use and sell things from, not to redistribute as files — https://xemstudio.com/license/. Other publishers' files: their own license, linked beside them.",
 "slug": "aquarium-airline-tubing",
 "name": "Aquarium airline tubing and fittings: 3/16 in vs 4 × 6 mm, check valves, connectors and Luer barb match",
 "kind": "standard",
 "category": "Tri-clamp & pipe",
 "group": "Pipe, tube & threads",
 "year": null,
 "question": "What size is aquarium airline tubing, and do check valves and fittings take 3/16 in or 4 mm tube?",
 "tags": [
  "airline tubing",
  "aquarium tubing",
  "air pump tubing",
  "check valve",
  "air tube",
  "fish tank",
  "4mm tube",
  "3/16 tubing",
  "tote"
 ],
 "aliases": [
  "airline tubing size",
  "aquarium air tubing 3/16 inch in mm",
  "4mm 6mm airline tubing",
  "aquarium check valve tubing size",
  "airline tubing id od",
  "is airline tubing 3/16 or 4mm",
  "air pump tube diameter",
  "aquarium air line connector size"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "not-scanned",
 "les": false,
 "free_files": 0,
 "url": "https://xemstudio.com/objects/aquarium-airline-tubing/",
 "sheet_txt": "https://xemstudio.com/objects/aquarium-airline-tubing/sheet.txt",
 "sheet": {
  "basis": "retailer and maker listings read (Bluviva, Perfect Ponds & Koi, Lee's, Aquaneat, Penn Plax); only the tubing ID and OD are printed, no fitting dimensions",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Two sizes are sold as standard airline tubing: 4 mm ID × 6 mm OD (metric listings) and \"3/16 in\" (US listings). The 4 mm and 3/16 in (4.76 mm) are not the same number, and the US listings read here do not print the OD of their 3/16 in tube, so the page does not claim the two are interchangeable; the 3/16 in value is the tube's nominal size, and Lee's calls it the ID of the tube its check valve takes.",
   "Fittings (check valves, 2- and 3-way valves, L- and T-connectors, splitters) are listed as 'for 3/16 in' or 'for 4 mm' tubing. No listing read prints a barb diameter, length or port size for these parts, so there are no fitting dimensions here and no files.",
   "A Luer barb that fits this tube: the nearest sizes in Nordson's and Qosina's tables are 5/32 in (4.0 mm ID) and 3/16 in (4.8 mm ID) tube barbs, see luer-to-barb-adapters. Silicone and PU push-fit tube sizes (including the 4 × 6 mm tube) are on silicone-tube-and-fittings.",
   "Not covered: pump outlet nozzle diameters, air-stone barbs and CO2 tubing, which were not read."
  ],
  "table": {
   "columns": [
    "item",
    "ID",
    "OD",
    "wall",
    "source"
   ],
   "rows": [
    [
     "airline tubing, metric",
     "4 mm",
     "6 mm",
     "about 1 mm (computed, (OD − ID)/2)",
     "Bluviva (\"4/6 mm\" as the usual size for most air pumps and attachments); Perfect Ponds & Koi (4 mm ID, 6 mm OD)"
    ],
    [
     "airline tubing, \"3/16 in\"",
     "3/16 in (4.76 mm, computed)",
     "not printed",
     "not printed",
     "Aquaneat listing: \"Standard 3/16 in\" tubing; Penn Plax listing: \"3/16 in\" (no ID/OD split in either); Lee's: pumps that use 3/16 in ID tubing"
    ],
    [
     "L-shaped connector",
     "for 4 mm ID tubing",
     "—",
     "—",
     "Aquaneat listing (no part dimensions printed)"
    ],
    [
     "air control valve (2-way / 3-way)",
     "for 4 mm tubing, or \"3/16 in ID\"",
     "—",
     "—",
     "Aquaneat listings (no part dimensions printed)"
    ],
    [
     "check valve",
     "for 3/16 in airline tubing",
     "—",
     "—",
     "Lee's 12405, Aquaneat and other listings read (no part dimensions printed)"
    ]
   ]
  }
 },
 "sheet_text": "Aquarium airline tubing and fittings: 3/16 in vs 4 × 6 mm, check valves, connectors and Luer barb match — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/aquarium-airline-tubing/  (sheet CC BY 4.0)\nBasis: retailer and maker listings read (Bluviva, Perfect Ponds & Koi, Lee's, Aquaneat, Penn Plax); only the tubing ID and OD are printed, no fitting dimensions\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Two sizes are sold as standard airline tubing: 4 mm ID × 6 mm OD (metric listings) and \"3/16 in\" (US listings). The 4 mm and 3/16 in (4.76 mm) are not the same number, and the US listings read here do not print the OD of their 3/16 in tube, so the page does not claim the two are interchangeable; the 3/16 in value is the tube's nominal size, and Lee's calls it the ID of the tube its check valve takes.\n- Fittings (check valves, 2- and 3-way valves, L- and T-connectors, splitters) are listed as 'for 3/16 in' or 'for 4 mm' tubing. No listing read prints a barb diameter, length or port size for these parts, so there are no fitting dimensions here and no files.\n- A Luer barb that fits this tube: the nearest sizes in Nordson's and Qosina's tables are 5/32 in (4.0 mm ID) and 3/16 in (4.8 mm ID) tube barbs, see luer-to-barb-adapters. Silicone and PU push-fit tube sizes (including the 4 × 6 mm tube) are on silicone-tube-and-fittings.\n- Not covered: pump outlet nozzle diameters, air-stone barbs and CO2 tubing, which were not read.\n\nitem  ID  OD  wall  source\nairline tubing, metric  4 mm  6 mm  about 1 mm (computed, (OD − ID)/2)  Bluviva (\"4/6 mm\" as the usual size for most air pumps and attachments); Perfect Ponds & Koi (4 mm ID, 6 mm OD)\nairline tubing, \"3/16 in\"  3/16 in (4.76 mm, computed)  not printed  not printed  Aquaneat listing: \"Standard 3/16 in\" tubing; Penn Plax listing: \"3/16 in\" (no ID/OD split in either); Lee's: pumps that use 3/16 in ID tubing\nL-shaped connector  for 4 mm ID tubing  —  —  Aquaneat listing (no part dimensions printed)\nair control valve (2-way / 3-way)  for 4 mm tubing, or \"3/16 in ID\"  —  —  Aquaneat listings (no part dimensions printed)\ncheck valve  for 3/16 in airline tubing  —  —  Lee's 12405, Aquaneat and other listings read (no part dimensions printed)\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- Bluviva: Airline and fittings category: standard airline tubing 4/6 mm (ID/OD); fittings should match the tubing — web — Retailer page; numbers only — https://bluviva.com/product-category/equipment/aeration/airline-fittings/\n- Perfect Ponds & Koi: H/D clear per meter airline 4 mm ID, 6 mm OD — web — Retailer page; numbers only — https://www.perfectpondsandkoi.co.uk/products/per-meter-airline-h-d-clear-4mmid-6mm-od\n- That Pet Place (Lee's check valve 12405): Lee's airline check valve: all air pumps that use 3/16 in ID tubing — web — Retailer page; numbers only — https://www.thatpetplace.com/check-valve-1pk_2\n- Walmart listing (Aquaneat airline tubing): Standard 3/16 in airline tubing; check valves for 3/16 in tubing; L-shaped connectors and air control valves for 4 mm ID tubing — web — Retailer listing; numbers only — https://www.walmart.com/ip/Aquaneat-Aquarium-Airline-Tubing-40Feet-Standard-3-16-Tubing-for-Air-Pump/541130335\n\nNo true-size file yet: the published figures do not fix the whole shape; a measured scan is planned.\nAPI: https://xemstudio.com/api/geometry?object=aquarium-airline-tubing\n",
 "sources": [
  {
   "publisher": "Bluviva",
   "title": "Airline and fittings category: standard airline tubing 4/6 mm (ID/OD); fittings should match the tubing",
   "url": "https://bluviva.com/product-category/equipment/aeration/airline-fittings/",
   "formats": [
    "web"
   ],
   "license": "Retailer page; numbers only",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Perfect Ponds & Koi",
   "title": "H/D clear per meter airline 4 mm ID, 6 mm OD",
   "url": "https://www.perfectpondsandkoi.co.uk/products/per-meter-airline-h-d-clear-4mmid-6mm-od",
   "formats": [
    "web"
   ],
   "license": "Retailer page; numbers only",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "That Pet Place (Lee's check valve 12405)",
   "title": "Lee's airline check valve: all air pumps that use 3/16 in ID tubing",
   "url": "https://www.thatpetplace.com/check-valve-1pk_2",
   "formats": [
    "web"
   ],
   "license": "Retailer page; numbers only",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Walmart listing (Aquaneat airline tubing)",
   "title": "Standard 3/16 in airline tubing; check valves for 3/16 in tubing; L-shaped connectors and air control valves for 4 mm ID tubing",
   "url": "https://www.walmart.com/ip/Aquaneat-Aquarium-Airline-Tubing-40Feet-Standard-3-16-Tubing-for-Air-Pump/541130335",
   "formats": [
    "web"
   ],
   "license": "Retailer listing; numbers only",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "not-scanned",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "silicone-tube",
  "luer-to-barb-adapters",
  "luer-connectors-iso-594-80369-7",
  "transfer-elbow-4mm",
  "drip-irrigation-tubing-sizes",
  "tri-clamp-hose-barb-adapters",
  "tygon-vinyl-tubing-e-3603-sizes"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no tolerance added)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no tolerance added. 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. Typical accuracy by process and ISO 286 fits: https://xemstudio.com/tolerances/",
 "mating": [],
 "faq": [
  {
   "q": "What size is standard aquarium airline tubing?",
   "a": "Retailers list 4 mm ID × 6 mm OD (metric) and 3/16 in nominal (US). The US listings read do not print an OD."
  },
  {
   "q": "Does a 3/16 in check valve fit 4 mm tubing?",
   "a": "The listings say 3/16 in valves are for 3/16 in tubing and some connectors are for 4 mm ID tubing; no listing prints the valve's barb size, so test the fit on your own tubing."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/aquarium-airline-tubing/index.md"
}