Medical Gas Pipeline Installation: From First Fix to Handover

Before any pipe is cut

Installation starts with an approved design, a named governing standard and a quality plan. Confirm the standard (see our comparison of HTM 02-01, NFPA 99 and ISO 7396-1), the pipe sizes, zone valve locations and the schedule of outlets. Agree how pipes and fittings will be delivered, stored and kept clean on site.

Pipe supplied for medical gas should be cleaned for oxygen service and capped at both ends. Reject any length that arrives uncapped or visibly dirty, and store it off the floor in a covered area.

Hold a pre-installation meeting with the contractor, consultant and hospital engineering team to agree hold points, inspection windows and who signs off each stage.

First fix: pipe routes, supports and joints

First fix covers the routing of pipes through ceilings, risers and walls, the installation of supports, and the fitting of back boxes and valve boxes before walls are closed. Medical gas copper pipe is the usual material, joined by brazing for the main lines; the question of medical gas piping is most often joined by brazing, not soft soldering, has a simple answer based on strength, cleanliness and safety.

Copper tube is cut with a wheel cutter, deburred, and fitted without contamination. Pipes must be separated from electrical cables, identified at intervals and supported so that they do not sag or transfer loads to joints.

Keep a simple pipe-cleanliness log. Each delivery, capped end and opened bundle can be recorded, so that if contamination is found later its origin can be traced quickly.

• Capped, oxygen-cleaned pipe and fittings only
• Brazing by qualified brazers with approved procedure
• Supports at the spacing required by the design
• Valve boxes and outlets located per the schedule

Brazing with nitrogen purge

While brazing, oxygen-free nitrogen flows through the pipe to prevent internal oxide scale. Scale can later flake off and block regulators, outlet valves and equipment. The purge flow should be controlled and continue until the joint has cooled, and open ends should be vented safely.

Use the filler alloy and flux (or flux-free alloys for copper-to-copper) that the specification allows. Qualified personnel should record each brazer's identity against the joints they made, so any failure can be traced.

Brazing in confined ceiling voids needs fire precautions, hot-work permits and a fire watch, because the hospital is normally occupied and adjacent materials may be combustible.

Second fix, labelling and the medical gas piping system

After wall finishes are complete, second fix connects outlets, zone valve units, alarm panels, bed head units and ceiling pendants. This is also when the pipework is labelled with gas names and flow direction, and when outlets are fitted with gas-specific connectors.

Items such as digital area valve service units and alarm monitoring units must be mounted at the heights and positions in the design. For how the parts of the system fit together read medical gas pipeline components.

Plan access for future service: valve boxes and alarm panels should be reachable without moving furniture or removing finished ceilings, and every box should carry a legible label.

Testing, contractor qualifications and services

Typical tests include pressure and leakage tests, cross-connection checks, flushing and purging, pressure drop and flow tests at outlets and verification of gas identity and purity before use. The tests must be witnessed and recorded; see medical gas testing and commissioning for details.

When selecting medical gas pipeline services, ask for evidence of qualified brazers, a quality plan, calibrated test equipment and relevant project references. Beckfinity represents MZ Liberec in the UAE; contact our specialists to discuss your project.