Pipeline systems
Cross-connection
A cross-connection is a fault in a medical gas pipeline where one gas or vacuum service is joined to the pipework or outlets of another, so that a patient or a device can receive the wrong gas.
Preventing cross-connection is a basic aim of the pipeline standards. ISO 7396-1 sets requirements for non-interchangeability between the components of different gas and vacuum systems, ISO 9170-1 requires terminal units that are gas-specific and cannot be interchanged between gases and services, and ISO 7396-2 requires anaesthetic gas scavenging disposal systems to avoid cross connections with medical gas and vacuum pipelines.
HTM 02-01 (2026) states that it is essential to rule out any possibility of a cross-connection between parts of the medical gas pipeline system, and that every part users can connect to is gas-specific. Its validation and verification include a cross-connection test in two stages: from the plant to the departmental area valve service units (AVSUs), then from the AVSUs to the terminal units. In the first stage, each gas supply system is opened in turn and gas flow is checked at the departmental AVSUs; the results go on form B21.
The pipeline equipment Ultra Controlo supplies, from manifolds and valves to alarms and outlets, is built to EN ISO 7396-1.
Sources
- ISO 7396-1:2016, Medical gas pipeline systems, Part 1 (ISO summary)
- ISO 9170-1:2017, Terminal units for medical gas pipeline systems (ISO summary)
- ISO 7396-2:2007, Anaesthetic gas scavenging disposal systems (ISO summary)
- HTM 02-01 (2026) Part A, paragraphs 2.5 and 19.226 to 19.228 (NHS England)
- Ultra Controlo, Medical gas answers: MGPS equipment built to EN ISO 7396-1
Ultra Controlo figures come from its technical datasheets. Third-party facts were read at the source on the date shown.