What bs2871 copper alloy tube solutions are recommended for medical gas piping?

In a hospital, the gases flowing through the wall — oxygen, medical air, vacuum, nitrous oxide, surgical driving air — are as critical as the electricity and water behind the panel. A single contaminated joint, an unsuitable tube alloy, or an undersized wall can shut down an operating theatre. That is why most hospital specifications still default to one specific material: a clean, seamless, de-greased copper tube that meets BS 2871 copper alloy tube requirements (now superseded for medical gas service by BS EN 13348, but still widely referenced). This guide explains which BS 2871 / BS EN 13348 copper alloy tube grades and tempers are recommended for medical gas piping, where they fit on a modern project, and how to specify them with confidence.

Why copper alloy is still the default for medical gas systems

Copper has been used in medical gas pipelines for more than half a century because it ticks every box that matters in a clinical environment:

• Clean internal surface. Properly manufactured and de-greased copper leaves virtually no lubricant residue — the BS EN 13348 limit is 0.20 mg/dm² for tubes up to 133 mm OD, so oxygen, nitrous oxide and medical air stay free of hydrocarbon contamination that could otherwise feed a fire.
• Inherent antimicrobial behaviour. Copper alloy surfaces in contact with moist air resist biofilm formation, which is important in sterile zones and ward manifolds.
• Pressure capability. Hard-temper R290 (minimum 290 MPa tensile) is rated for continuous service up to 2 000 kPa, the upper limit set by BS EN 13348 for medical gases.
• Workability on site. Half-hard R250 tube bends cleanly with standard tube benders up to 28 mm, while annealed R220 soft coil handles long runs behind ceilings and risers.
• Recyclable and documented. Copper is 99 % recyclable and carries EN 1057 / EN 13348 / BS 2871 mill certificates for full traceability — a key requirement for HTM 02-01 and ISO 7396-1 audits.

On modern projects these advantages are exactly why the copper & nickel alloy range still anchors the medical, marine and pharmaceutical piping scope.

BS 2871 vs. BS EN 13348 — which one should you actually specify?

BS 2871 Part 1 was the long-standing British standard for copper tubes in water, gas and sanitation. It has been progressively replaced by a family of EN standards:

For new-build hospitals, our recommendation is unambiguous: specify BS EN 13348:2016 degreased copper tube for every medical gas line — oxygen, medical air, surgical air, nitrous oxide, vacuum and AGSS — and reference BS 2871 only when matching legacy spares or extensions of an existing installation.

Recommended tube grades and tempers for medical gas piping

BS EN 13348 (and the BS 2871 line it replaced for medical service) recognises three tempers of the same deoxidised copper grade — Cu-DHP / CW024A, equivalent to UNS C12200 and Chinese TP2. Each temper covers a specific duty on the pipeline:

For most hospital projects we recommend an R250 straight-length body with R220 soft coil for the final metre of distribution near outlets, and R290 only on the high-pressure ring main or where the line exits the medical air plant. This mix balances ease of brazing, support spacing and the all-important cleanliness of the gas stream.

Recommended sizes and matching fittings

BS EN 13348 lists both "R" (recommended) and "X" (other European) sizes. The diameters most often used in medical gas systems are:

• Bedhead branches & pendant drops: 12 × 1.0 mm, 15 × 1.0 mm (R250 / R290 hard drawn).
• Zone valves & ward manifolds: 22 × 1.0 mm, 28 × 1.0 mm (R250).
• Vertical risers: 35 × 1.2 mm, 42 × 1.2 mm, 54 × 1.2 mm or 54 × 2.0 mm (R250 / R290).
• Plant-room mains and ring lines: 66.7 × 2.0 mm, 76.1 × 2.0 mm, 108 × 2.5 mm, up to 159 × 3.0 mm or 219 × 3.0 mm for large teaching hospitals.

Every joint on a medical gas line must be made with fittings that are themselves manufactured for oxygen-clean service. Brazed copper-to-copper joints with a copper/phosphorus or copper/silver filler (5 % Ag minimum, < 0.05 % Cd) are still the most widely accepted method. For retrofits, dezincification-resistant brass press fittings rated for medical gas may be used, but they should be traceable to the same standard and supplied with the matching tube.

You can browse the matching BS 2871 copper alloy tube and copper-nickel fittings ranges on our site, and pair them with the broader copper & nickel alloy inventory for clean utilities, vacuum and AGSS lines.

Specifying a BS 2871 / BS EN 13348 medical gas tube correctly

A clean specification avoids the most common audit findings. Use the wording below as a baseline and adapt it to your project:

1. Material & standard. "Seamless round copper tube to BS EN 13348:2016, deoxidised, Cu-DHP / CW024A (Cu + Ag ≥ 99.90 %, 0.015 % ≤ P ≤ 0.040 %), degreased for medical gas service, supplied capped at both ends." Where the project still references BS 2871, add: "or BS 2871 Part 1 Table X (legacy) for matching existing systems."
2. Temper & mechanical properties. R220 (annealed), R250 (half hard) or R290 (hard) per the duty table above; Rm and elongation minimums as published in BS EN 13348 §6.
3. Dimensional tolerances. Outside-diameter tolerance per BS EN 13348 (e.g. ±0.04 mm for 6–18 mm OD, ±0.06 mm for 28–54 mm OD, ±0.20 mm for 108–159 mm OD), wall-thickness tolerance ±10 % for tubes under 18 mm OD and ±10 / ±15 % for larger sizes.
4. Cleanliness. Internal lubricant residue ≤ 0.20 mg/dm² (≤ 0.38 mg/dm² above 133 mm OD); supplied in sealed polyethylene bags or with end caps; stored off-site on pallets, not directly on concrete floors.
5. Marking. Each length permanently marked in black ink with: tube standard (EN 13348), temper (R220 / R250 / R290), nominal dimensions (e.g. 22 × 1.0), manufacturer, batch / heat number and the "MED" or medical gas designation.
6. Documentation. Mill test certificate to EN 10204 type 3.1 covering chemical composition, mechanical properties, dimensional check, cleanliness, eddy-current or hydrostatic test, and traceability of the source copper cathode.
7. Joining & supports. Brazed joints only, with copper/phosphorus or copper/silver filler containing ≤ 0.05 % Cd; no soft solder on medical gas lines. Plastic or copper/brass supports with full insulation against electrolytic contact with carbon-steel structures.

Where the same tube family serves adjacent clean utilities

Medical gas projects rarely end at the oxygen line. The same de-greased copper philosophy extends to:

• Laboratory gas and pure water loops — overlap with our petrochemical & clean process copper-nickel grades, where higher Cu-Ni content is preferred for chloride-bearing streams.
• Seawater cooling & firemain branches — move up to 90/10 or 70/30 Cu-Ni to match EEMUA 234 / marine & ship-building requirements.
• Nitrogen, helium and specialty gas headers — for ultra-high purity needs, our ASTM B163 nickel alloy tube range gives a step-change in corrosion allowance without losing the brazing-friendly fabrication logic.

Specifying one supplier across the medical gas, clean utility and seawater circuits removes the most painful variable on a hospital build — interface compatibility between the tube, fittings, flanges and valves.

A short checklist before you sign the purchase order

• Standard is BS EN 13348:2016 (or BS 2871 only for legacy extensions).
• Temper matches the duty (R220 coil for long bends, R250 straight for distribution, R290 for the high-pressure ring).
• Sizes fall on the "R" recommended list where possible, and tolerances are stated in mm, not "to manufacturer standard".
• Internal cleanliness ≤ 0.20 mg/dm² and end caps are fitted.
• Marking, MTC 3.1 and traceability are contractually required, not "available on request".
• Filler metal for brazing is named: copper/phosphorus or copper/silver with Cd ≤ 0.05 %.
• The supplier confirms parallel supply of fittings, flanges, gaskets and valves so the medical gas package arrives complete.

Final recommendation

For any new medical gas installation, the safest recommendation is to specify BS EN 13348:2016 degreased copper tube in R250 (half hard) straight lengths as the baseline, with R220 annealed coil for the long ceiling runs and R290 hard tube only where pressure or mechanical protection demands it. Reference BS 2871 in the spec only for matching existing systems and approved spares. Pair the tube with brazed copper fittings, a copper/phosphorus or copper/silver filler, full MTC 3.1 traceability, and a manufacturer that can also support the adjacent copper-nickel, brass and stainless lines.

If you are planning a hospital, laboratory, or clean utility build and need help matching the tube to fittings, flanges and valves, send your piping class and material take-off to export@ezsteelpipe.com — our engineering team can return a full material schedule, MTC template and lead-time proposal against the BS 2871 copper alloy tube inventory within one working day.