Can the medical gas pipeline be used as an earth for equipment?

Not under HTM 02-01, which says pipelines should not be used for earthing electrical equipment; they should instead be bonded together, to the local distribution board and to the main earth terminal.

Do pipe clips have to be plastic?

HTM 02-01 does not name a material: supports should be of a suitable material or suitably treated so that they minimise corrosion and prevent electrolytic reaction with the pipe.

Do copper medical gas pipes need earthing or isolation from supports?

Q: Do copper medical gas pipelines need electrical bonding under HTM 02-01, and do they need to be isolated from metal supports?

Under HTM 02-01 (2026), the NHS England guidance, copper medical gas pipelines should be electrically bonded together, to the local distribution board and to the main earth terminal where they enter and leave a building, but not used to earth equipment, and their supports should not react electrolytically with the pipe.

Do copper medical gas pipelines need electrical bonding under HTM 02-01, and do they need to be isolated from metal supports?

HTM 02-01 Part A (2026 edition) covers both points: the pipeline should be electrically bonded in accordance with BS 7671 and HTM 06-01, and supports should be of a suitable material, or suitably treated, to minimise corrosion and prevent electrolytic reaction with the pipe. In Portugal, the ACSS specification ET 03/2006 (revised 2024) also asks for medical gas networks to be earthed.

Bonding

Medical gas pipelines should be bonded together and to the local electrical distribution board in accordance with HTM 06-01 and BS 7671, and bonded to the main earth terminal at building entry and exit.
Pipelines should not be used for earthing electrical equipment.
Flexible pipeline connections should be visually bonded across their fixed points to keep earth continuity.
Where a medical gas outlet or pipeline is in a Group 2 location, as defined in Section 710 of BS 7671, the resistance of the bonding connection should meet the required value.
Contact with electrical services should be avoided. Where separation is impractical or the pipe touches other metalwork, for example in metal partitions or where terminal units are mounted on metal bedhead units, the pipeline should be bonded to that metalwork.
Where pipes cross other services and a 25 mm clearance cannot be kept, they should be electrically bonded and wrap-insulated.

Supports and contact materials

Supports should be of a suitable material, or suitably treated, to minimise corrosion and prevent electrolytic reaction between pipes and supports (see pipe support spacing).
Where it is essential for pipes to cross electric cables or conduit, they should be supported at close intervals on either side so that they do not touch.
Pipework may corrode in contact with timber treated with fire-retardant compounds; impermeable non-metallic materials, such as PVC spacers or adhesive PVC tape, should be used at the points of contact.
Enclosures for runs through hazardous areas should be non-combustible and non-corrosive, with no electrolytic reaction with copper.

Lightning, pendants and inspection

To protect it from lightning strikes, pipework should run within a 60-degree cone beneath the lightning conductor, for example along parapet walls. Inside booms and rigid pendants, low voltage, extra-low voltage and data systems should be kept together but separate from the pipelines. HTM 02-01 Part B lists the security of, and any damage to, electrical bonding among the items checked when exposed pipework is inspected.