Ultra Controlo Medical gas library

Glossary

The terms behind medical gas systems, defined. 120 pages.

A

  • Activated carbon filterActivated carbon filter: how it adsorbs oil vapour and odours from compressed air, where HTM 02-01 and WHO place it, and the ULTRAK and ULTRAMED figures.
  • Adsorber column (sieve bed)Adsorber column (sieve bed): the zeolite vessel in a PSA oxygen generator, how its two columns cycle, what AIGA 113/20 asks for, and the ULTRACON columns.
  • Adsorption (desiccant) dryerAdsorption (desiccant) dryer: how it dries compressed air to low pressure dew points, how medical air dryers regenerate it, and the ULTRADRY range.
  • AFNOR outlet (NF S90-116)AFNOR outlet: the French medical gas socket and probe system of NF S90-116 (2020 edition), how it relates to ISO 9170-1 and other national outlet styles.
  • AGSSAnaesthetic gas scavenging system: removes waste anaesthetic gases from operating rooms.
  • AGSS disposal systemAGSS disposal system: the fixed pump, pipework and terminal units that remove waste anaesthetic gases from theatres, under ISO 7396-2 and HTM 02-01 (2026).
  • AGSS flow indicatorAGSS flow indicator: the airflow normal indication, dental unit flow indicator and quarterly checks that NHS England's HTM 02-01 (2026) sets for scavenging.
  • AGSS receiving systemAGSS receiving system: the part of the anaesthetic equipment between the transfer hose and the AGSS terminal unit, in HTM 02-01 (2026) and ISO 7396-2.
  • Anaesthetic gas scavenging system (AGSS) terminal unitAGSS terminal unit: where an anaesthetic gas scavenging disposal system meets the receiving system, the two ISO 9170-2 types and HTM 02-01 (2026) rules.
  • Area alarmArea alarm: the ward or theatre panel that monitors medical gas pressure and vacuum in one AVSU zone, as described in the NHS England guidance HTM 02-01 (2026).
  • Area valveA valve box that isolates one zone of the pipeline for maintenance or in an emergency.
  • As-built drawingsAs-built drawings: where WHO (2024), UNDP (2025) and the Global Fund ask for them at oxygen plant handover, and HTM 02-01 as-fitted pipeline drawings.
  • Authorised Person (MGPS)Authorised Person (MGPS): the person who runs a hospital medical gas pipeline day to day under HTM 02-01 (2026), how they are appointed and what they do.
  • Automatic changeoverSwitching from a primary supply to a reserve supply without interrupting the flow.

B

  • Bacterial filterBacterial filter: where it sits in hospital vacuum plant and medical air treatment, what HTM 02-01 (2026) asks of it, and the ULTRAVAC configuration.
  • BMS (building management system)The hospital’s central system for monitoring building and plant equipment.
  • Brazing (medical gas copper)Brazing medical gas copper pipes: CP104 alloy, no flux and an oxygen-free nitrogen shield under HTM 02-01 (2026), plus ACSS and the NFPA 99-2021 dental text.
  • BS (HTM) outletBS (HTM) outlet: the British medical gas terminal unit to BS 5682 that HTM 02-01 asks for, the other national outlet styles, and how it is tested.

C

  • CGA 540 cylinder valve connectionCGA 540 cylinder valve connection: where WHO's 2024 oxygen cylinder, filling and manifold specifications list it, and what the CGA V-1 standard covers.
  • Class 0The most stringent oil class for compressed air in ISO 8573-1. Ultra Controlo describes its oil-less ULTRACECO compressors as Class 0.
  • Cleaned for oxygen serviceCleaned for oxygen service: what degreased, particle-free medical gas pipe means under HTM 02-01 (2026), EN 13348 and ISO 15001, and why oil is a risk.
  • Coalescing filterCoalescing filter: how it removes water and oil aerosols from compressed air, where HTM 02-01, ACSS and WHO place it, and its use in ULTRADRY and ULTRAMED.
  • CommissioningCommissioning: testing and documenting a new or modified medical gas installation before use, under HTM 02-01 (2026) and the 2024 Global Fund PSA guideline.
  • Condensate drain (drain trap)Condensate drain: how drain traps remove water and oil from compressed air, the four types of drain, HTM 02-01 and ACSS rules, and Ultra Controlo examples.
  • Corrective maintenanceCorrective maintenance: WHO's 2011 definition, what it means for PSA oxygen plants per PATH and WHO (2024), and the SLA terms UNDP (2025) asks suppliers for.
  • Cross-connectionCross-connection: a pipeline fault that lets the wrong gas reach an outlet. How ISO 7396-1, ISO 9170-1 and the HTM 02-01 two-stage test prevent it.
  • Cryogenic air separationCryogenic air separation: how air separation units distil air into liquid oxygen, the Ph. Eur. 0417 grade it makes, and how it differs from on-site PSA.

D

  • Derating (altitude and site conditions)Derating: why PSA oxygen plants rated at 1,000 ft or lower are derated higher up, and the site conditions that WHO, PATH, AIGA 113/20 and HTM 02-01 give.
  • Design life of an oxygen plantDesign life of an oxygen plant: the 10-year lifespan WHO (2020 and 2024) and UNDP (2025) ask manufacturers to guarantee, and HTM 02-01 component design lives.
  • Dew point monitorDew point monitor: the sensor tracking how dry compressed air is after the dryer, HTM 02-01 and ACSS alarm rules, and monitoring on ULTRAAR ME and ULTRAMED.
  • DIN outletDIN outlet: the German medical gas terminal unit and probe system of DIN 13260-2, whose 2025 edition adds probes for oxygen 93, argon and surgical tool gases.
  • DISS connector (Diameter Index Safety System)DISS connector: the Diameter Index Safety System of CGA V-5 for non-interchangeable medical gas connections up to 200 psi, and where it is used.
  • Diversity factorDiversity factor: how medical gas designers size pipes and plant for realistic simultaneous use, with the HTM 02-01 (2026) rules for theatres and dental air.
  • Duty and standbyDuty and standby: one unit of a medical gas supply runs while another waits to take over, as HTM 02-01 (2026) applies it to manifolds, compressors and dryers.

E

  • EDQM (European Directorate for the Quality of Medicines & HealthCare)EDQM: the Council of Europe directorate that compiles and publishes the European Pharmacopoeia, including the monographs for medical oxygen and medicinal air.
  • Emergency supply inletEmergency supply inlet: the pipeline connection through which a mobile liquid oxygen vessel can feed a hospital network, and how HTM 02-01 (2026) treats it.
  • EN ISO 7396-1International standard for pipeline systems for compressed medical gases and vacuum.
  • EN ISO 7396-2International standard for anaesthetic gas scavenging disposal systems.

F

  • FAT (factory acceptance test)FAT (factory acceptance test): checking equipment at the vendor before delivery, as EU GMP Annex 15 (2015) describes it, and what UNDP asks of oxygen plants.
  • Free air delivery (FAD)Free air delivery (FAD): compressor output stated as free air at atmospheric conditions, how HTM 02-01 uses it, and ISO 1217 in Ultra Controlo tables.

G

  • Gas-specific probeGas-specific probe: the connector that fits only one medical gas outlet, the national standards that size it (BS 5682, DIN 13260-2, NF S90-116) and its tests.

H

  • HMI (human-machine interface)HMI (human-machine interface) on an oxygen plant: WHO's 2024 control panel/user interface requirements and the touch-screen controls in UC datasheets.
  • HTM 02NHS England Health Technical Memorandum guidance for medical gas pipeline systems (HTM 02-01).
  • Hub-and-spoke oxygen supplyHub-and-spoke oxygen supply: one central plant fills cylinders for surrounding facilities, with the pros and cons a 2023 Global Fund briefing note lists.

I

  • Instrument airInstrument air: compressed air for surgical tools and drying medical devices, as ACSS ET 08 and CSA Z7396.1 use the term, and why it is not technical air.
  • ISO 13485International standard for the quality management systems of medical device manufacturers.
  • ISO 14001ISO 14001: the environmental management system standard, its 2026 edition replacing ISO 14001:2015, certification, and the Ultra Controlo certificate.
  • ISO 8573-1 purity classISO 8573-1 purity class: how compressed air is rated for particles, water and oil, what [2:4:2] means, and why medical air follows the pharmacopoeia.
  • ISO 9001ISO 9001: the quality management system standard, its 2026 edition replacing ISO 9001:2015, what certification means, and ISO 13485 for medical devices.

L

  • Line isolation valveLine isolation valve: the valve used to isolate risers, branches and supply connections of a medical gas pipeline, and how HTM 02-01 (2026) specifies it.
  • Litres per minute (L/min, LPM)Litres per minute (L/min, LPM): the flow unit for patient and outlet oxygen, how WHO converts it to m³/h for PSA plants, and how plant ratings use it.
  • Long-term agreement (LTA) in UN procurementLong-term agreement (LTA) in UN procurement: UNGM and UN Handbook (2022) definitions, how buyers use LTAs, and UNDP's 2025 duties for oxygen plant awardees.
  • Low pressure switchLow pressure switch: how Ultra Controlo describes its switch for medical gas alarm triggering, and what HTM 02-01 (2026) says about pressure switches.
  • Low-pressure hose assemblyLow-pressure hose assembly: what ISO 5359:2014 covers for medical gas hoses, its limits and revision, and how HTM 02-01 (2026) says hoses should be used.

M

  • ManifoldAn assembly that connects cylinder banks to the pipeline at a constant pressure.
  • Manifold pigtailManifold pigtail: the flexible link from a gas cylinder valve to a manifold, how Global Fund procedures change and check it, and the WHO warning on leaks.
  • Master alarmMaster alarm: the alarm system that, in 2021 NFPA 99 text, watches supply sources and main line pressure of medical gas pipelines, and the HTM plant alarm.
  • Medical airCompressed air of pharmacopoeia quality, supplied through the pipeline to patients and medical equipment.
  • Medical gas alarm relayMedical gas alarm relay: how Ultra Controlo describes its relays for pipeline pressure and zone valve alarms, and the HTM 02-01 (2026) fail-safe relay rule.
  • Medical vacuumMedical vacuum: the hospital piped suction service, from pumps and bacteria filters to terminal units, with the HTM 02-01 (2026) design vacuum.
  • MGPSMedical gas pipeline system: the network that carries medical gases and vacuum from the supply to each point of use.
  • MTBF (mean time between failures)MTBF (mean time between failures): WHO's 2011 definition as a corrective maintenance measure, its use in a CMMS, and what WHO (2024) asks of oxygen plants.

N

  • NIST connector (non-interchangeable screw-threaded)NIST connector: the non-interchangeable screw-threaded medical gas connector of ISO 18082:2014, and where HTM 02-01 (2026) asks for it in a pipeline.
  • Normal cubic metre (Nm³)Normal cubic metre (Nm³): gas volume stated at fixed reference conditions, the EU definition of 273.15 K and 101,325 Pa, and how oxygen datasheets use it.

O

  • Oil-injected compressorOil-injected compressor: what the injected oil does, how it is separated from the air, how HTM 02-01 treats it for medical air, and the ULTRASCREW range.
  • Outlet check valve (terminal unit check valve)Outlet check valve: the valve in a terminal unit that closes when the socket is removed, so one outlet can be repaired live, as HTM 02-01 (2026) describes.
  • Oxygen 93Medical oxygen produced from air by PSA, with 90.0% to 96.0% oxygen by volume (Ph. Eur. 2455; USP Oxygen 93 Percent).
  • Oxygen 99.5 (medical oxygen, Ph. Eur. 0417)Oxygen 99.5: medicinal oxygen of at least 99.5% made by cryogenic distillation, as in Ph. Eur. 0417 and the International Pharmacopoeia, versus PSA oxygen.
  • Oxygen concentratorOxygen concentrator: a device that removes nitrogen from air on molecular sieves, its ISO 80601-2-69 standard and limits, and the ULTRACON in ULTRAOX plants.
  • Oxygen flowmeterOxygen flowmeter: what it is, the Thorpe tube, Bourdon and dial types, ISO 15002:2023 and the HTM 02-01 (2026) warnings on gas and paediatric ranges.
  • Oxygen Plant-in-a-BoxOxygen Plant-in-a-Box: UNICEF's emergency PSA plant package (brief, November 2021), its standard and containerized versions, and how oxygen reaches patients.
  • Oxygen receiver (buffer tank)Oxygen receiver or buffer tank: the vessel that stores PSA oxygen before the pipeline, how AIGA 113/20 asks for it to be sized, and the ULTRAOX oxygen tanks.
  • Oxygen securityOxygen security: the aim of the Lancet Global Health Commission (2025), its system view and figures, WHO's facility-level system security and WHA76.3.
  • Oxygen-enriched airOxygen-enriched air: the term the withdrawn ISO 10083 used for concentrator gas in medical gas pipelines, and its other meaning as a fire hazard in room air.

P

  • Paramagnetic oxygen analyserParamagnetic oxygen analyser: measures oxygen through its paramagnetic properties; HTM 02-01 (2026) specifies it for oxygen identity tests and PSA plants.
  • Performance bond (performance security)Performance bond (performance security): the UN Procurement Practitioner's Handbook (2022) definition, typical 10% value, forms and when it is returned.
  • Ph. Int. (International Pharmacopoeia)Ph. Int.: the International Pharmacopoeia published by WHO, its purpose, and the 13th edition (2025) monograph that defines Oxygen 93%, 98% and 99.5%.
  • Pin index safety systemPin Index Safety System (PISS): valve pins and holes unique to each medical gas, ISO 407:2023 yoke-type connections, and where pin-index valves are used.
  • Pipeline purgePipeline purge: flushing a medical gas pipeline with nitrogen or its working gas to clear air, shield gas and particles, under HTM 02-01 (2026) and NFPA 99.
  • Piston (reciprocating) compressorPiston (reciprocating) compressor: how a piston compresses air, lubricated and oil-less designs, HTM 02-01 notes, and the ULTRACECO ESW piston range.
  • Plant alarmPlant alarm: the medical gas alarm that reports manifolds, compressors and vacuum plant to a 24-hour central panel, with the HTM 02-01 (2026) signals.
  • PLC (programmable logic controller)PLC, programmable logic controller: the controller whose program runs the valves of a PSA oxygen plant, what operators read on it, and the ULTRAOX screen.
  • Plume evacuationPlume evacuation: removing surgical smoke from lasers and electrosurgery, the HTM 02-01 (2026) advice on piped vacuum, and what CSA Z7396.1 says.
  • Potential-free contactA relay contact with no voltage of its own, used to pass an alarm signal to another system.
  • Pressure dew pointThe temperature at which water starts to condense from compressed air at its working pressure. The lower it is, the drier the air.
  • Pressure relief valve (medical gas line)Pressure relief valve on a medical gas line: where HTM 02-01 (2026) says relief and safety valves go, their capacity, discharge and five-year replacement.
  • Preventive maintenancePreventive maintenance: planned servicing of medical gas systems under HTM 02-01 (2026), what PSA plant schedules cover, and the UltraCare programme.
  • PSA (pressure swing adsorption)Separates oxygen from air: a molecular sieve holds back nitrogen under pressure and releases it when the pressure drops. The process inside ULTRAOX.

Q

  • QuAirQuAir: the PLC controller in ULTRACECO scroll compressors, how it starts and stops the skids, the QuAir 3 touch screen, and where else Ultra Controlo uses it.
  • QuPHARMQuPHARM: the wall-mounted analyser from Ultra Controlo that measures O2, CO and CO2 in on-site medical oxygen, its sensors, alarms and BMS outputs.
  • QuVACQuVAC: the digital touch-screen controller of ULTRAVAC medical vacuum plants, which in ULTRAVAC DENTAL units rotates the pumps and starts them progressively.

R

  • Refrigeration dryerRefrigeration dryer: how cooling removes water from compressed air, where it stops short of an adsorption dryer, and the ULTRASEC refrigeration dryer.
  • Rotary screw compressorRotary screw compressor: how two meshing rotors compress air, why oil-injected types need oil separation, and where ULTRASCREW compressors are used.
  • Rotary vane vacuum pumpRotary vane vacuum pump: a vane-type positive displacement pump, oil-lubricated or dry, required for medical vacuum by Portugal's ACSS and used in ULTRAVAC.

S

  • SAT (site acceptance test)SAT (site acceptance test): testing equipment once it reaches site, as EU GMP Annex 15 (2015) describes it, and the on-site tests asked of PSA oxygen plants.
  • Scroll compressorScroll compressor: how two spiral scrolls compress air, why oil-free scrolls suit medical air, and the ULTRACECO SC range used in ULTRAAR SC plants.
  • Second-stage regulatorSecond-stage regulator: the regulator that makes the second pressure reduction in a medical gas network, under ISO 10524-2, HTM 02-01 and ACSS ET 03/2006.
  • Side channel blowerSide channel blower: the rotary vacuum and pressure machine behind anaesthetic gas scavenging and dental suction, and where Ultra Controlo uses it.
  • Skid-mounted oxygen plantSkid-mounted oxygen plant: WHO's 2024 delivery options for oxygen generator plants, size limits per WHO (2023), housing needs per UNDP and PATH.
  • Soft starter (compressor motor)Soft starter: why WHO's 2024 oxygen plant specifications ask for it on the air feed compressor, and the starting current data UNDP (2025) asks suppliers for.
  • Suction collection jarSuction collection jar: the container that holds aspirated fluid, the HTM 02-01 (2026) rules on suction jars, and the jars fitted in vacuum plants and risers.
  • Suction regulatorSuction regulator: the device on a medical vacuum outlet that sets suction at the point of care, the HTM 02-01 (2026) slam-shut and filter rule, ISO 10079.
  • Surgical air (air for driving surgical tools)Surgical air (air for driving surgical tools): pipeline pressures in HTM 02-01 and ACSS ET 03/2006, supply options, and how it differs from medical air.
  • Synthetic medical airSynthetic medical air: medical air blended from oxygen and nitrogen, covered by Ph. Eur. monograph 1684 and by ISO 7396-3:2025 for proportioning units.

T

  • Terminal unitThe gas outlet where medical equipment connects to the pipeline, on a bed-head unit, a wall or a ceiling pendant.
  • Third-source panelThird-source panel: the control panel of a three-source medical gas cylinder manifold, and how HTM 02-01 and the ACSS name and define the three sources.

U

  • ULTRACECOULTRACECO: the Ultra Controlo compressor family, from oil-less scroll and piston air compressors to oil-free high pressure oxygen compressors.
  • UNGM (United Nations Global Marketplace)UNGM (United Nations Global Marketplace): the UN system's common procurement portal, what suppliers and UN buyers do there, and UNICEF's use of it.
  • UPS (uninterruptible power supply)UPS, uninterruptible power supply: battery back-up for the controls of a PSA oxygen plant, the 1 kW size Open Critical Care advises, and plant back-up.
  • USP (United States Pharmacopeia)USP: the United States Pharmacopeia, its FDA-enforceable USP-NF standards, and its oxygen monographs, Oxygen (99.0%) and Oxygen 93 Percent (90 to 96%).

V

  • Vacuum receiverVacuum receiver: the vessel that lets medical vacuum pumps run efficiently at low use, the HTM 02-01 (2026) and ACSS rules, and ULTRAVAC vessel sizes.
  • VIE (vacuum-insulated evaporator)VIE (vacuum-insulated evaporator): how a bulk liquid oxygen vessel stores and vaporises oxygen for the pipeline, per NHS England's HTM 02-01 (2026).
  • VIPR (valve with integrated pressure regulator)VIPR (valve with integrated pressure regulator): what ISO 10524-3:2019 covers, how HTM 02-01 (2026) describes it, and WHO's 2024 cylinder valve options.
  • VPSA (vacuum pressure swing adsorption)VPSA (vacuum pressure swing adsorption): oxygen made with low-pressure feed air and vacuum purging, as WHO and a 2025 Global Fund note describe it.
  • VSA (vacuum swing adsorption)A related process that works at low pressure and releases the nitrogen under vacuum. The process inside ULTRAOX VSA.
  • VSD (variable speed drive)Motor control that matches compressor speed to demand, to save energy.

W

  • WAGD (waste anesthetic gas disposal)WAGD (waste anesthetic gas disposal): the NFPA 99 term, its scope per the US CMS rule (2016), OSHA disposal methods and the AGSS term of ISO and HTM 02-01.
  • WHO Listed Authority (WLA)WHO Listed Authority (WLA): WHO's 2024 definition, how regulators are listed, regulatory reliance, and how UNDP and the Global Fund use WLA approval.

Z

  • Zeolite molecular sieveThe adsorbent in a PSA column that holds back nitrogen and lets oxygen through.
  • Zirconia oxygen analyserZirconia oxygen analyser: how a zirconia cell measures oxygen through the Nernst voltage, and where zirconia and paramagnetic sensors are used on PSA plants.