A medical gas network is not ordinary pipework: it feeds patients whose survival depends on uninterrupted flow and gas purity. ISO 7396-1 governs the whole chain, from the source to the wall outlet.
Three requirements come up at every technical acceptance: redundancy of supply sources, traceability of materials — degreased copper compliant with directive 93/42/EEC, a class IIA medical device — and continuous monitoring through service alarms.
The calculation is based on peak flow rates, never on averages.
Sizing is the second pitfall. An undersized plant passes the tests and fails in service, when several theatres run at once. The calculation is based on peak flow rates, never on averages.
In practice the feasibility study determines everything else: that is when the number of sources, the network topology and the position of the second-stage regulators are decided.
