Updated 2026-09-07

Building Code Glossary

Cylinder: Building Code Definition

How the IFC 2009 define cylinder, where the wording differs, and which chapters depend on the term.

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Last updated September 7, 2026 · Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control.

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Direct answer

Cylinder is a defined term in the International Fire Code (IFC) 2009, in Hazardous Materials-general Provisions. The code's own words are: “A pressure vessel designed for pressures higher than 40 psia (275.6 kPa) and having a circular cross section. It does not include a portable tank, multi-unit tank car tank, cargo tank or tank car.” No other I-Code in this corpus defines it, so the IFC 2009 definition is the one to work from. The term is used in 21 chapters of this corpus, most often in Compressed Gases (IFC 2009), Highly Toxic and Toxic Materials (IFC 2009), Motor Fuel-dispensing Facilities and Repair Garages (IFC 2009). These pages transcribe the 2009 model text; verify the definition against the edition and amendments your authority having jurisdiction has adopted.

Content and cited inputs reviewed by Scott Barrington, Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.

What does this term mean?

Cylinder — IFC 2009, Hazardous Materials-general Provisions:

A pressure vessel designed for pressures higher than 40 psia (275.6 kPa) and having a circular cross section. It does not include a portable tank, multi-unit tank car tank, cargo tank or tank car.

Labeled code-term definition diagram: Cylinder: Building Code Definition — How the IFC 2009 define cylinder, where the wording differs, and which chapters depend on the term.

What must be verified before using this guidance?

Cylinder is defined once in this corpus, in the Hazardous Materials-general Provisions chapter of the International Fire Code (IFC) 2009:

A pressure vessel designed for pressures higher than 40 psia (275.6 kPa) and having a circular cross section. It does not include a portable tank, multi-unit tank car tank, cargo tank or tank car.

Where cylinder is used in the code

The term appears in 21 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

Chapter	Code	Mentions
Compressed Gases	IFC 2009	150
Highly Toxic and Toxic Materials	IFC 2009	82
Motor Fuel-dispensing Facilities and Repair Garages	IFC 2009	58
Flammable Gases and Flammable Cryogenic Fluids	IFC 2009	41
Welding and Other Hot Work	IFC 2009	40
Hazardous Materials-general Provisions	IFC 2009	36
Semiconductor Fabrication Facilities	IFC 2009	20
Oxidizers, Oxidizing Gases and Oxidizing Cryogenic Fluids	IFC 2009	15
Masonry	IBC 2009	13
Pyrophoric Materials	IFC 2009	9
Liquefied Petroleum Gases	IFC 2009	7
Fire Protection Systems	IFC 2009	6

9 further chapters mention the term.

The term in use

How the code actually writes about cylinder, quoted from the 2009 text hosted here:

Compressed gas container, cylinder and tank valves shall be protected from physical damage by means of protective caps, collars or similar devices in accordance with Sections 3003.6.1 and 3003.6.2.

— IFC 2009 §3003.6

The maximum flow rate of release for portable tanks and cylinders shall be calculated based on the total release from the cylinder or tank within the time specified in Table 3704.2.2.7.5.

— IFC 2009 §3704.2.2.7.5

The discharge of CNG from motor vehicle fuel cylinders for the purposes of maintenance, cylinder certification, calibration of dispensers or other activities shall be in accordance with Sections 2208.8.1 through 2208.8.1.2.6.

— IFC 2009 §2208.8

The terms cylinder is built out of

The definition above leans on 2 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what cylinder covers:

Pressure Vessel — IFC 2009: A closed vessel designed to operate at pressures above 15 psig (103 kPa).
Vessel — IFC 2009: A motorized watercraft, other than a seaplane on the water, used or capable of being used as a means of transportation.

Cylinder: what to open, and in what order

Every row is a document this term depends on. The ICC code library and the ICC adoption maps cover the middle rows.

Check	Where	Confirmed
Read the definition in the adopted IFC	Hazardous Materials-general Provisions
Re-check the requirement that uses it	Compressed Gases (IFC 2009)
Re-check the requirement that uses it	Highly Toxic and Toxic Materials (IFC 2009)
Re-check the requirement that uses it	Motor Fuel-dispensing Facilities and Repair Garages (IFC 2009)
Re-check the requirement that uses it	Flammable Gases and Flammable Cryogenic Fluids (IFC 2009)
Confirm the dependent definition	Pressure Vessel
Confirm the dependent definition	Vessel
Local amendment to any of the above	Jurisdiction's amendment list

A research aid, not a code determination. The authority having jurisdiction decides which edition and which amendments apply.

Sources and method

Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The ICC code library publishes the current model text and the ICC adoption maps show which edition a jurisdiction has adopted; those sources control.

Source links

Frequently asked questions

What is the code definition of cylinder?

The International Fire Code (IFC) 2009 defines it in Hazardous Materials-general Provisions as: “A pressure vessel designed for pressures higher than 40 psia (275.6 kPa) and having a circular cross section. It does not include a portable tank, multi-unit tank car tank, cargo tank or tank car.” The 2009 model text is reproduced here; the definition that binds your project is the one in the edition your jurisdiction has adopted, as amended locally.

Which parts of the code depend on cylinder?

In this corpus the term is used across 21 chapters, led by Compressed Gases in the IFC 2009. Those are the sections whose scope moves if the definition is amended locally, so read them together with Chapter 2 rather than on their own.

What is the definition of a building code?

Building is a separate defined term. The IBC 2009 defines it as: “Any structure used or intended for supporting or sheltering any use or occupancy.” That is not the same as cylinder, which the IFC 2009 defines as “A pressure vessel designed for pressures higher than 40 psia (275.6 kPa) and having a circular cross section. It does not include a portable tank, multi-unit tank car tank, cargo tank or tank car.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

What does the code on a gas cylinder mean?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IFC 2009 states, in Hazardous Materials-general Provisions: “A pressure vessel designed for pressures higher than 40 psia (275.6 kPa) and having a circular cross section. It does not include a portable tank, multi-unit tank car tank, cargo tank or tank car.” It is defined in IFC 2009. Because it is a defined term, whatever the adopted edition says it means is what every section using it means — so check Chapter 2 of that edition and any local amendment before relying on this wording.

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