Is a bigger oxygen tank enough for a surge?

Not necessarily. HTM 02-01 (2026) notes that during COVID-19 bulk supply was generally sufficient and the limiting factor was often the pipeline's ability to deliver the required flow to patients.

How many ward beds should allow high-flow oxygen?

Portugal's ACSS ET 03/2006 (v.2024) recommends that 20% of ward beds, and all intensive care and emergency observation beds, can receive up to 60 L/min.

How can an oxygen pipeline be upgraded for surge ICU demand?

Q: How can an existing hospital oxygen pipeline be upgraded when wards are converted to high-flow or ICU use during a surge?

Under HTM 02-01 (2026), the NHS England guidance, areas designed for CPAP, BiPAP or non-invasive ventilation can have their complete flow loops upgraded, typically by one pipe size; this is the preferred solution, and a dedicated pipeline is not recommended because it can cause control and flow issues.

How can an existing hospital oxygen pipeline be upgraded when wards are converted to high-flow or ICU use during a surge?

What COVID-19 showed

The 2026 edition of HTM 02-01 explains that, while bulk oxygen supply was generally sufficient during the pandemic, the limiting factor was often the ability of the pipeline system to deliver the required flow to patients, and that modern therapies and the concentration of high-dependency patients exposed constraints in pipeline capacity and configuration. It notes that high flow use risked starving terminal units downstream of a significant load, and places more emphasis on designing for peak and surge demand. Portugal's ACSS specification ET 03/2006 (revised 2024) notes that, given the constraints identified during the COVID-19 pandemic, there was some difficulty providing oxygen for high-flow nasal oxygen, since existing systems had not been designed for it, and that, according to feedback from several hospitals, high flows may range from 15 to 60 L/min.

Check the existing network first

Recalculate: HTM 02-01 Part B asks for a risk-based design process whenever additions or alterations are made, with design flow and pressure drop checked and recalculated so there are no pinch points. In a fully operational hospital, it is standard practice to run the calculations from several locations, including main pipe runs, high flow areas, theatres and the furthest points.
Design basis: the overall pipeline design is based on a 5% pressure drop from the source to the terminal unit outlet at the specified test flows, and Table 2 gives oxygen terminal units a design flow of 60 L/min in critical care units against 10 L/min in all other areas.
Older systems: insufficient capacity may prevent safe operation at today's flow rates; a risk assessment and flow calculations are required before work, and pinch points found are put right before the project is completed.
Users: the hospital's procedures should make users aware of the system's capacity and limits; HTM 02-01 notes that adopting CPAP can significantly increase oxygen consumption.

Upgrade options

Source	Option
HTM 02-01 Part A, paras 4.10 to 4.12	For areas designed for CPAP, BiPAP or non-invasive ventilation: upgrade the complete flow loops for the higher flows, typically by increasing the pipe size by one size, or install dedicated pipelines. HTM 02-01 does not recommend the dedicated option (dedicated high-flow terminal units are likely to cause confusion in an emergency, and a dedicated pipeline can cause control and flow issues); the preferred solution is to increase the flow-loop pipe size.
HTM 02-01 Part A, para 4.8	Ladder arrangements and ring mains for distribution, and flow loops in wards and departments, for greater resilience.
ACSS ET 03/2006 (v.2024), section 6.7	A dedicated network, connected directly from the manifold or as a ring, for intensive care and emergency observation services; pressure reduction sets as close as possible to the points of use. ACSS recommends that all intensive care and emergency observation beds, and 20% of ward beds, can receive high flow up to 60 L/min.

At the supply end

HTM 02-01 notes that the vaporisers of a liquid oxygen (VIE) installation may ice up where demand is high or continuous, and lists options such as additional vaporisers, automatic changeover between vaporisers, automatic de-icing and larger vaporisers. Each backfeed kit for emergency supply should be risk-assessed against the department's flow and duration needs, with high-flow scenarios considered, where icing of regulators and hoses may cause supply failure. For the effect of high-flow oxygen on the plant itself, see how high-flow oxygen changes demand; for carrying out the works in a live hospital, see extending a pipeline in a working hospital.