# What is a medical gas ceiling pendant?

**What is a medical gas ceiling pendant, and where is it used?**

A medical gas ceiling pendant is a ceiling-mounted medical supply unit that brings gas outlets, electrical sockets and data services to the patient in operating theatres, intensive care and recovery rooms, either as a fixed unit or on movable arms fed by flexible hoses.

HTM 02-01 Part B, the NHS England guidance (2026 edition), lists booms and ceiling pendants among medical supply units, the category covered by ISO 11197:2019 for basic safety and essential performance. For a circular array of terminal units, for example on the underside of a pendant, HTM 02-01 uses the same order as a horizontal wall array, clockwise when viewed from below, with the AGS outlet allowed in the centre.

## Fixed or multi-movement

- HTM 02-01 makes fixed pendants the default, to remove the need for flexible connections. A multi-movement pendant needs review by the Authorising Engineer (MGPS) and approval from the hospital's Medical Gas Safety Group.
- In movable pendants, hoses complying with BS EN ISO 5359 run from the terminal unit NIST through the unit to a female NIST in the ceiling, with minimal excess length; excess length can lead to kinking, twisting and increased pressure drop.
- Hoses are replaced every five years unless environmental conditions or the manufacturer's recommendations call for sooner replacement, and the replacement date is displayed on the outside of the pendant.
- A separate 600 mm x 600 mm access hatch close to the pendant is recommended for the ceiling NISTs.
- When planning operating-room pendants, the position of the operating luminaire and other ceiling devices is taken into account. With an ultra-clean ventilation (UCV) system, it may be more practicable to build the services into the UCV system; HTM 02-01 notes that this is particularly advantageous for surgical air, as rigid pipework avoids the pressure losses of flexible assemblies in pendants.

## Brakes, electrics and maintenance

- Electrical brakes are preferred for moving pendants. Medical air should not power pendant control or braking systems; where pneumatic brakes are used, each pendant needs its own surgical air AVSU and flow control system.
- Electrical, communications and data services are kept together but separate from the pipelines, and unprotected live parts inside the pendant can be reached only with a tool.
- During quarterly tests, the probe must be free to rotate in a pendant or boom outlet, whereas it should not swivel in a wall outlet.
- Moving or replacing pendants with flexible hoses on NIST connectors is listed under high-hazard work in the permit to work system, as a case where a cross-connection hazard may arise.

Ultra Controlo supplies ceiling-mounted medical gas pendants for intensive care units, operating theatres and recovery rooms, with oxygen, air, vacuum and electrical services, and a pendant with a double swivel arm for theatres and intensive care bays.

### How often are pendant hoses replaced?

HTM 02-01 asks for replacement every five years, unless environmental conditions or the manufacturer's recommendations call for sooner replacement.

### Can medical air drive pendant brakes?

Not under HTM 02-01, which says medical air systems should not power pendant control and braking systems, and prefers electrical brakes for moving pendants.

## Sources

- [NHS England, HTM 02-01 (2026) Part B, paragraphs 4.10 and 7.77, and the quarterly terminal unit tasks in chapter 11](https://www.england.nhs.uk/wp-content/uploads/2016/05/health-technical-memorandum-02-01-medical-gas-pipeline-systems-part-b-operational-management-aug-26.pdf)
- [NHS England, HTM 02-01 (2026) Part A, paragraphs 3.12, 3.19, 3.23, 3.24, 3.45, 3.48, 3.55, 3.69, 7.100, 15.33 and 15.162](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 11197:2019 Medical supply units (iso.org summary)](https://www.iso.org/standard/74384.html)
- [ultracontrolo.com: Medical Gas Ceiling Pendants for ICU and Theatre](https://www.ultracontrolo.com/accessories/medical-gas-pendants)
- [ultracontrolo.com: Medical Gas Pendants with Double Swivel Arm](https://www.ultracontrolo.com/accessories/medical-gas-pendants-with-double-swivel-arm)

Reviewed: 2026-10-22. Ultra Controlo engineering. https://library.ultracontrolo.com/answers/what-is-a-medical-gas-pendant/