# ISO 18082:2014 NIST low-pressure connectors for medical gases

ISO 18082:2014 is the ISO standard for the dimensions, allocation and marking of non-interchangeable screw-threaded (NIST) low-pressure connectors for medical gases, at operating pressures up to 1 400 kPa and for vacuum; it is in force with Amendment 1:2017, and its revision has been at DIS ballot since 25 September 2026.

## What the standard covers

ISO 18082 specifies the dimensions, allocation and marking of NIST connectors intended for operating pressures up to 1 400 kPa and for vacuum systems at pressures not greater than 60 kPa absolute. The connectors are specified for oxygen, nitrous oxide, medical air, helium, carbon dioxide, xenon, specified mixtures of these gases, oxygen-enriched air, air and nitrogen for driving surgical tools, and vacuum.

## Edition in force and status

- ISO 18082:2014 is the first edition, published in June 2014 (12 pages, ISO/TC 121/SC 1). Amendment 1 was published in July 2017, and ISO lists it as available free of charge in read-only format.
- ISO states that the standard was last reviewed and confirmed in 2020; it is now at stage 90.92 (to be revised), and ISO expects it to be replaced by ISO/DIS 18082 within the coming months.
- ISO/DIS 18082 (edition 2, 10 pages) was approved as a project on 6 October 2025, registered as a draft on 23 July 2026, and has been at DIS ballot since 25 September 2026.

## How NIST connectors are used

Under HTM 02-01 (2026), the NHS England guidance, NISTs are threaded connection devices designed to prevent cross-connection, and for all pressure gases they incorporate a check valve. They should be installed where gas testing, emergency backfeeding or connection of flexible hoses is required, and where carbon dioxide is specified, a NIST connection is required, not a probe connection.

## Related standards

- [ISO 5359](https://library.ultracontrolo.com/standards/iso-5359/): low-pressure hose assemblies for medical gases; it does not specify the dimensions and allocation of the gas-specific connectors of the hose assemblies.
- [ISO 9170-1](https://library.ultracontrolo.com/standards/iso-9170-1/): terminal units for compressed medical gases and vacuum; it does not specify the dimensions of probes.

### What pressures does ISO 18082 cover?

Operating pressures up to 1 400 kPa, and vacuum systems at pressures not greater than 60 kPa absolute.

### Is ISO 18082 being revised?

Yes. ISO/DIS 18082 has been at DIS ballot since 25 September 2026, and ISO expects it to replace the 2014 edition within the coming months.

## Sources

- [ISO 18082:2014, NIST low-pressure connectors (iso.org)](https://www.iso.org/standard/61329.html)
- [ISO 18082:2014/Amd 1:2017 (iso.org)](https://www.iso.org/standard/68681.html)
- [ISO/DIS 18082, edition 2 (iso.org)](https://www.iso.org/standard/93004.html)
- [NHS England, HTM 02-01 (2026), Part A: Design, installation, validation and verification](https://www.england.nhs.uk/wp-content/uploads/2016/05/health-technical-memorandum-02-01-medical-gas-pipeline-systems-part-a-design-installation-validation-verification-aug-2026.pdf)
- [ISO 5359:2014, Low-pressure hose assemblies (iso.org)](https://www.iso.org/standard/59953.html)
- [ISO 9170-1:2017, Terminal units, Part 1 (iso.org)](https://www.iso.org/standard/67451.html)

Reviewed: 2026-10-22. Ultra Controlo engineering. https://library.ultracontrolo.com/standards/iso-18082/