Building Code Glossary
Safety Valve: Building Code Definition
How the IMC 2009 define safety valve, where the wording differs, and which chapters depend on the term.
On this page
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.
Direct answer
Safety valve is a defined term in the International Mechanical Code (IMC) 2009, in Definitions. The code's own words are: “A valve that relieves pressure in a steam boiler by opening fully at the rated discharge pressure. The valve is of the spring-pop type.” No other I-Code in this corpus defines it, so the IMC 2009 definition is the one to work from. The term is used in 3 chapters of this corpus, most often in Boilers, Water Heaters and Pressure Vessels (IMC 2009), Definitions (IMC 2009), Fuel Gas (IRC 2009). These pages transcribe the 2009 model text; verify the definition against the edition and amendments your authority having jurisdiction has adopted. Record the jurisdiction, the adopted edition, the application date and any local amendment that rewrites the definition before you use it on a live project, because a term redefined by amendment changes every requirement that depends on it.
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?
Safety Valve — IMC 2009, Definitions:
A valve that relieves pressure in a steam boiler by opening fully at the rated discharge pressure. The valve is of the spring-pop type.
What must be verified before using this guidance?
Safety Valve is defined once in this corpus, in the Definitions chapter of the International Mechanical Code (IMC) 2009:
A valve that relieves pressure in a steam boiler by opening fully at the rated discharge pressure. The valve is of the spring-pop type.
Where safety valve is used in the code
The term appears in 3 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.
| Chapter | Code | Mentions |
|---|---|---|
| Boilers, Water Heaters and Pressure Vessels | IMC 2009 | 4 |
| Definitions | IMC 2009 | 1 |
| Fuel Gas | IRC 2009 | 1 |
The term in use
How the code actually writes about safety valve, quoted from the 2009 text hosted here:
All steam boilers shall be protected with a safety valve.
The terms safety valve 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 safety valve covers:
- Boiler — IRC 2009: A self-contained appliance from which hot water is circulated for heating purposes and then returned to the boiler, and which operates at water pressures not exceeding 160 pounds per square inch gage (psig) (1102 kPa gauge) and at water temperatures …
- Valve — IRC 2009: A device used in piping to control the gas supply to any section of a system of piping or to an appliance.
Safety Valve: 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 IMC | Definitions | |
| Re-check the requirement that uses it | Boilers, Water Heaters and Pressure Vessels (IMC 2009) | |
| Re-check the requirement that uses it | Definitions (IMC 2009) | |
| Re-check the requirement that uses it | Fuel Gas (IRC 2009) | |
| Confirm the dependent definition | Boiler | |
| Confirm the dependent definition | Valve | |
| 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.
Where can you explore related guidance?
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 safety valve?
The International Mechanical Code (IMC) 2009 defines it in Definitions as: “A valve that relieves pressure in a steam boiler by opening fully at the rated discharge pressure. The valve is of the spring-pop type.” 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 safety valve?
In this corpus the term is used across 3 chapters, led by Boilers, Water Heaters and Pressure Vessels in the IMC 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 legal definition of a safety valve?
In the 2009 I-Codes hosted here it is a defined term rather than a description. The IMC 2009 states, in Definitions: “A valve that relieves pressure in a steam boiler by opening fully at the rated discharge pressure. The valve is of the spring-pop type.” It is defined in IMC 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.
Related pages
- Rough-in: Building Code Definition
Rough-in — IRC 2009 definition: The installation of all parts of the plumbing system that must be completed prior to the …
- Running Bond: Building Code Definition
Running Bond — IBC 2009 definition: The placement of masonry units such that headjoints in successive courses are horizontally offset at least …
- Safety Can: Building Code Definition
Safety Can — IFC 2009 definition: An approved container of not more than 5-gallon (19 L) capacity having a spring-closing lid and …
- Sanitary Sewer: Building Code Definition
Sanitary Sewer — IRC 2009 definition: A sewer that carries sewage and excludes storm, surface and groundwater.
- Scissor Stair: Building Code Definition
Scissor Stair — IBC 2009 definition: Two interlocking stairways providing two separate paths of egress located within one stairwell enclosure.
- Scupper: Building Code Definition
Scupper — IBC 2009 definition: An opening in a wall or parapet that allows water to drain from a roof.