# Piping System: Building Code Definition

> How the IRC 2009 define piping system, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/piping-system/
- Last updated: 2026-09-07
- Data source: 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.

## Key facts

| Fact | Value |
| --- | --- |
| Defined in | IRC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IRC 2009 Fuel Gas (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 40 (counted across the codes hosted here) |
| Wording identical across codes | Single code (compare before citing one code's wording under another) |

## Direct answer

Piping system is a defined term in the International Residential Code (IRC) 2009, in Fuel Gas. The code's own words are: “All fuel piping, valves and fittings from the outlet of the point ofdeliveryto the outlets of the appliance shutoff valves.” No other I-Code in this corpus defines it, so the IRC 2009 definition is the one to work from. The term is used in 40 chapters of this corpus, most often in Fuel Gas (IRC 2009), Flammable and Combustible Liquids (IFC 2009), Cryogenic Fluids (IFC 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](https://nz.linkedin.com/in/barrington), Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.*

## What does this term mean?

**Piping System** — IRC 2009, Fuel Gas:

> All fuel piping, valves and fittings from the outlet of the point ofdeliveryto the outlets of the appliance shutoff valves.

![Labeled code-term definition diagram: Piping System: Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/piping-system/diagram-1344.webp)

*How the IRC 2009 define piping system, where the wording differs, and which chapters depend on the term.*

## What must be verified before using this guidance?

**Piping System** is defined once in this corpus, in the [Fuel Gas](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md) chapter of the International Residential Code (IRC) 2009:

> All fuel piping, valves and fittings from the outlet of the point ofdeliveryto the outlets of the appliance shutoff valves.

## Where piping system is used in the code

The term appears in 40 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Fuel Gas](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md) | IRC 2009 | 82 |
| [Flammable and Combustible Liquids](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/flammable-and-combustible-liquids.md) | IFC 2009 | 33 |
| [Cryogenic Fluids](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/cryogenic-fluids.md) | IFC 2009 | 31 |
| [Water Supply and Distribution](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/water-supply-and-distribution.md) | IRC 2009 | 19 |
| [Motor Fuel-dispensing Facilities and Repair Garages](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/motor-fuel-dispensing-facilities-and-repair-garages.md) | IFC 2009 | 17 |
| [Hydronic Piping](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/hydronic-piping.md) | IMC 2009 | 16 |
| [Compressed Gases](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/compressed-gases.md) | IFC 2009 | 13 |
| [Building Services and Systems](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/building-services-and-systems.md) | IFC 2009 | 9 |
| [Fuel Oil Piping and Storage](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/fuel-oil-piping-and-storage.md) | IMC 2009 | 8 |
| [Use and Occupancy Classification](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/use-and-occupancy-classification.md) | IBC 2009 | 7 |
| [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/ipc-2009/definitions.md) | IPC 2009 | 7 |
| [Hazardous Materials-general Provisions](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/hazardous-materials-general-provisions.md) | IFC 2009 | 6 |

_28 further chapters mention the term._

### The term in use

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

> Each above-ground portion of a gas piping system other than corrugated stainless steel tubing (CSST), that is likely to become energized shall be electrically continuous and bonded to an effective ground-fault current path.

— [IRC 2009 §G2411.1](https://harth.build/resources/building-codes/us-states/maryland/irc-2009/fuel-gas.md)

> Piping system components shall be designed and fabricated in accordance with the applicable standard listed in Table 3403.6.2 and Chapter 27 of NFPA 30, except as modified by Section 3403.6.2.1.

— [IFC 2009 §3403.6.2](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/flammable-and-combustible-liquids.md)

> Pressure relief valves shall be installed where liquid is capable of being trapped between shutoff-valves in the piping system (see Section 3203.2).

— [IFC 2009 §3205.1.2.3.2](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/cryogenic-fluids.md)


## The terms piping system is built out of

The definition above leans on 3 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what piping system covers:

- **[Appliance](https://harth.build/resources/glossary/appliance.md)** — IRC 2009: Utilization equipment, normally built in standardized sizes or types, that is installed or connected as a unit to perform one or more functions such as clothes washing, air conditioning, food mixing, deep frying, etc.
- **[Outlet](https://harth.build/resources/glossary/outlet.md)** — IRC 2009: A point on the wiring system at which current is taken to supply utilization equipment.
- **[Piping](https://harth.build/resources/glossary/piping.md)** — IRC 2009: Where used in this code, “piping” refers to either pipe or tubing, or both.

## Piping System: what to open, and in what order

Every row is a document this term depends on. The [ICC code library](https://codes.iccsafe.org/codes) and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) cover the middle rows.

| Check | Where | Confirmed |
| --- | --- | --- |
| Read the definition in the adopted IRC | Fuel Gas | |
| Re-check the requirement that uses it | Fuel Gas (IRC 2009) | |
| Re-check the requirement that uses it | Flammable and Combustible Liquids (IFC 2009) | |
| Re-check the requirement that uses it | Cryogenic Fluids (IFC 2009) | |
| Re-check the requirement that uses it | Water Supply and Distribution (IRC 2009) | |
| Confirm the dependent definition | Appliance | |
| Confirm the dependent definition | Outlet | |
| Confirm the dependent definition | Piping | |
| 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?

- [Explore all glossary guidance](https://harth.build/resources/glossary.md)
- [Appliance: Building Code Definition](https://harth.build/resources/glossary/appliance.md)
- [Piping: Building Code Definition](https://harth.build/resources/glossary/piping.md)
- [Outlet: Building Code Definition](https://harth.build/resources/glossary/outlet.md)

## 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](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.

### Source links

- [codes.iccsafe.org](https://codes.iccsafe.org/codes)

- [iccsafe.org](https://www.iccsafe.org/advocacy/code-adoption-maps/)

## Frequently asked questions

### What is the code definition of piping system?

The International Residential Code (IRC) 2009 defines it in Fuel Gas as: “All fuel piping, valves and fittings from the outlet of the point ofdeliveryto the outlets of the appliance shutoff valves.” 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 piping system?

In this corpus the term is used across 40 chapters, led by Fuel Gas in the IRC 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 a piping system?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IRC 2009 states, in Fuel Gas: “All fuel piping, valves and fittings from the outlet of the point ofdeliveryto the outlets of the appliance shutoff valves.” It is defined in IRC 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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