What should a medical gas cylinder manifold tender specify?

HTM 02-01 Part A (2026 edition), the NHS England guidance on medical gas pipeline systems, sets out in chapter 5 what a cylinder manifold should do, and the points below follow it. Other countries apply their own references.

Role and size

• Type and role: an automatic changeover manifold (ACM) is required as the primary source when the main supply is cylinders, and as the secondary source backing up a mechanical or liquid system; a manual manifold should not be used as the secondary source in that case.
• Cylinders: both banks have the same number of cylinders, at most ten per bank on an ACM, with header racks that can be shortened or extended in place without brazing. Sizing by duration is explained in how to size a cylinder manifold.
• Flow: the control panel should pass the full pipeline design flow of the system it supplies, and be designed for gas that may fall to -30 °C through the regulator at maximum capacity.

Changeover and power

• Changeover from duty to standby bank should be automatic and controlled by cylinder pressure, leaving no more than 1400 kPa in the cylinders.
• The control system should let one bank be changed without loss of continuity of supply.
• If the changeover control depends on electricity, a power failure should not disrupt the flow of gas, and when power returns the bank that was running should be back online unless it has been depleted. HTM 02-01 warns that some older designs default to a fixed bank after a power failure.

Pressure control, valves and connections

• High-pressure regulators complying with BS EN ISO 10524-2, supplied with auto-ignition test results, and a separate pressure-regulating valve for each bank. ISO 10524-2 covers manifold regulators for manifold systems with a nominal inlet pressure of up to 300 bar.
• Manifolds and control panels designed and certificated for cylinders at 23,000 kPa.
• Self-closing pressure safety valves downstream of the regulators and upstream of the isolation valves, discharging outside the building (see pressure relief valves).
• A replaceable check valve in each manifold header, so that a ruptured tailpipe does not empty the whole bank.
• Flexible connections from cylinder to manifold to BS EN ISO 21969, which, as HTM 02-01 Part B summarises it, says non-metallic hoses should not be used.
• A test point on every manifold.

Indication, alarms and the room

Pressure in each bank and in the pipeline should stay visible even if power to the manifold or the display fails, and indicators should have a design life of at least five years; the alarm conditions are listed in manifold alarms. Manifolds should be located in a dedicated manifold room, with cylinder restraints between 60% and 75% of the cylinder body height (excluding the valve) and spare cylinders for one complete bank change held in the room.

Ultra Controlo

The ULTRAOX SC datasheet lists automatic changeovers and line regulators among the Ultra Controlo accessories for medical gas pipeline systems.