What maintenance does a medical gas cylinder manifold need?

HTM 02-01 Part B (2026 edition), NHS England's guidance on operational management, says every medical gas pipeline system should be subjected to a planned preventive maintenance schedule under the responsibility of the Authorised Person (MGPS); daily and weekly tasks are usually done by the hospital's estates team. For the whole system, see what maintenance a medical gas pipeline needs.

Routine checks

• Weekly: check plant and manifold gauges and indicators for abnormal conditions, absent displays or damage; check every manifold for security, heating and lighting, cylinder contents, cylinder dates and spare cylinders within the manifold room; check that cylinders are properly stored and secured.
• Weekly: check that manifold rooms and cylinder stores are free from combustible material, accessible for maintenance and not obstructed for natural ventilation.
• Monthly: check that safety notices are displayed and that cylinder batch labels are correct and in date.
• Daily, where a cylinder manifold backs up a liquid oxygen (VIE) plant: check and record that the pressures of its cylinders are above 50%.

At PSA oxygen plants, the daily checklist that Build Health International wrote for the Global Fund's Project BOXER asks whether the manifold pigtails are in good working condition and whether a backup manifold not used in the past day is maintaining pressure.

Before servicing: prove the reserve

HTM 02-01 Part A says there should be no maintenance or repairs on a manifold while it is in service; an alternative source of supply should be used. For an automatic manifold this is the emergency reserve manifold (ERM), which should be confirmed fully tested before it becomes the sole supply. Its capacity is much less than the automatic manifold's, so adequate stocks of replacement cylinders should be on hand; the appropriate personnel should be notified, and signage displayed at the plant alarms, that the system is to be tested and alarms are likely.

Servicing an automatic manifold

1. Transfer the supply to the ERM and monitor its cylinders constantly, with a second operative when heavy flow is expected.
2. Inspect components and cylinder restraints, with each cylinder individually secured, and verify any panel heaters.
3. Soap test the safety valve exhaust; a passing valve is replaced with a sealed, certificated unit.
4. Check full flow through each regulator, then watch its static pressure for 5 minutes: creepage means service or replacement.
5. Test the pressure switches on each bank: they should close at a maximum of 14 bar and raise a "change cylinders" alarm on the manifold panel and the main alarm system.
6. Test the non-return valve, then close all cylinder valves and watch the gauges for at least 10 minutes; a soap test or ultrasonic detector does not replace this static leak test.
7. Check each tailpipe (pigtail) non-return valve by disconnecting one tailpipe at a time: a minor weep is permissible, an obvious major leak means failure and replacement.
8. Run a changeover test on each bank: changeover at no more than 14 bar, then the "change cylinders immediately" indication, then the low-pressure alarm, whose pressure is recorded.
9. Hand the supply back from the ERM and check that the ERM is set to come online as the low pressure of the automatic manifold initiates.

The separate ERM procedure includes a test that its "reserve low" alarm operates when the pressure falls to 50% of the nominal full-cylinder pressure for compressed gas cylinders.

Longer intervals and records

HTM 02-01 does not recommend lifting safety valves; they are replaced every five years. A manifold backing up a liquid oxygen plant is tested annually to come online if the VIE fails, ward emergency supply manifolds at a frequency agreed with clinical colleagues, and a signed, dated report follows every visit.

Ultra Controlo supplies oxygen cylinder manifolds with automatic or manual switchover between primary and standby banks, and offers the UltraCare programme of preventive and corrective maintenance for its systems.