When a tender document for a hospital project asks for “medical grade copper tube”, it almost always points to one of two standards: the European standard EN 13348 or the American standard ASTM B819. Both exist for the same reason, to make sure copper tube used for medical gases is clean, consistent and safe, but they are not interchangeable on a drawing. This guide explains the differences and how to choose.
What both standards have in common
Both EN 13348 and ASTM B819 cover seamless copper tube intended for medical gas and vacuum systems. In each case the tube is made from phosphorus-deoxidised copper, a high-purity copper grade that brazes well and resists corrosion. Both standards also go beyond ordinary plumbing tube in one critical way: cleanliness.
Oxygen-enriched environments are unforgiving. Oil, grease or carbon residue left inside a tube can contaminate the gas a patient breathes, and in extreme cases can increase fire risk. So both standards set strict limits on residual contamination inside the bore, require the tube to be cleaned and degreased at the factory, and require the ends to be capped or plugged before dispatch so that the tube arrives on site as clean as it left the mill.
Key differences
1. Size system
This is the difference that matters most in practice. EN 13348 tubes are specified by their actual outside diameter in millimetres, for example 15 mm, 22 mm or 28 mm. ASTM B819 tubes follow the American nominal size system in inches, such as 1/2 inch or 3/4 inch, where the nominal size does not equal the outside diameter. Fittings, valves and terminal units must match the tube system, so a project designed to one standard should stay with it throughout.
2. Wall thickness
Each standard defines its own wall thickness for each size. ASTM B819 tube corresponds in dimensions to Type K and Type L water tube, while EN 13348 sets metric wall thicknesses. The values are close in many sizes but not identical, which affects pressure rating and weight.
3. Marking and identification
Both standards require permanent markings along the tube so that medical grade tube can be identified on site and kept separate from ordinary plumbing stock. The marking content differs, so site inspectors usually check markings against the specified standard.
4. Where each is used
EN 13348 is the usual choice for projects designed to European, British and many Middle Eastern and Asian specifications, including those following HTM 02-01 or ISO 7396-1. ASTM B819 is standard in North America and on projects designed to NFPA 99. Many export markets accept either, but the consultant’s specification decides.
How to choose
- Follow the specification. If the project documents name a standard, use it. Mixing systems causes fitting mismatches on site.
- Check fitting availability. Make sure elbows, tees, couplings and reducers are available in the same size system as the tube.
- Ask for documentation. A reputable supplier should provide a material test certificate confirming the grade, dimensions and cleanliness of each batch.
- Inspect the delivery. Tubes should arrive capped, clearly marked and free from dents or damage.
Common mistakes to avoid
The most common mistake is substituting ordinary plumbing tube for medical grade tube because it looks the same. Plumbing tube is not cleaned to medical standards and is not acceptable in an MGPS. Another mistake is removing end caps too early on site, which lets dust and moisture into the tube before installation.
Sourcing medical copper tube
Nefton Exports Industries supplies medical grade copper tubes and matching copper fittings for medical gas pipeline systems, with test certificates on every supply. Tell us which standard your project follows, the sizes and the quantities, and our team will send a quotation.
