Is ISO 9170-1 enough on its own?

No. ISO 9170-1 does not specify probe dimensions and points to regional or national standards for them; HTM 02-01, for example, asks for terminal units to conform to both BS 5682 and BS EN ISO 9170-1.

Can medical gas outlets be mounted in the floor?

Not under HTM 02-01, which does not permit floor-mounted terminal units.

How should medical gas outlets be specified in a tender?

Q: How should a tender specify medical gas outlets: standard, connector style, double closure, mounting and testing?

ISO 9170-1:2017 covers the gas-specific assembly, flow, leakage and pressure drop of medical gas outlets but leaves probe dimensions to regional or national standards, so a tender cannot rely on it alone; NHS England's HTM 02-01 (2026) also asks for BS 5682 and adds mounting, labelling, anti-swivel, "Do not use" plug and test requirements.

How should a tender specify medical gas outlets: standard, connector style, double closure, mounting and testing?

ISO 9170-1:2017 is the international standard for terminal units on medical gas and vacuum pipelines. Its purpose is gas-specific assembly, mechanical resistance, flow, leakage and pressure drop, and preventing a terminal unit from being interchanged between gases, but it does not specify probe dimensions. The ISO summary points to regional or national standards for probe dimensions (see outlet types). HTM 02-01 (2026 edition), the NHS England guidance, asks for terminal units to conform to both BS 5682 and BS EN ISO 9170-1.

What to write into the specification

Standard and connector style: ISO 9170-1 plus the regional or national connector standard in use (HTM 02-01 asks for BS 5682). In Portugal, the ACSS specification ET 03/2006 (revised 2024) asks for double-closure outlets that are not interchangeable between gases.
Performance: pressure losses across terminal units in accordance with ISO 9170-1, as HTM 02-01 asks, and the flows each outlet should pass (see outlet flow test). For vacuum, HTM 02-01 asks for at least 315.5 mmHg at the front of each terminal unit at a design flow of 40 L/min.
Gases and sequence: the services per room and the order of the array, which for a horizontal array in HTM 02-01 runs from left to right as oxygen, nitrous oxide, oxygen/nitrous oxide mixture, medical air, surgical air, vacuum, AGS and carbon dioxide; carbon dioxide uses a NIST connection, not a probe connection.
Mounting (HTM 02-01): wall terminal units between 900 mm and 1600 mm above finished floor level, centres 135 ± 2.5 mm apart for three or more units or 150 ± 2.5 mm for two; floor-mounted terminal units are not permitted.
Anti-swivel (HTM 02-01): terminal units for directly connected equipment, such as flowmeters, should include an anti-swivel device; units for hose connection only do not need one.
Units in medical supply units (HTM 02-01): a male NIST connector and nut brazed to the rear of the terminal unit.
Identification (HTM 02-01): dual-circuit terminal units should carry a colour-coded circular label around the outlet, with the gas at the top and the circuit below; in critical care areas the circuit numbers should match the area valve service units.
"Do not use" plugs (HTM 02-01): single-piece plugs that interlock with the probe-retaining mechanism, left in every second-fix outlet until it has been tested; stickers should not be used instead.

Testing after handover

HTM 02-01 Part B asks for all terminal units other than AGSS units to be tested quarterly, starting with a blank probe to check gas specificity, mechanical function and leaks (see how often outlets are tested).

Ultra Controlo

The ULTRAOX SC datasheet lists medical gas outlets, second stage regulators and valves among the Ultra Controlo accessories for medical gas pipeline systems.