Building Code Glossary
Drainage Fittings: Building Code Definition
How the IPC 2009 define drainage fittings, 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
Drainage fittings is a defined term in the International Plumbing Code (IPC) 2009, in Definitions. The code's own words are: “Type of fitting or fittings utilized in the drainage system. Drainage fittings are similar to cast-iron fittings, except that instead of having a bell and spigot, drainage fittings are recessed and tapped to eliminate ridges on the inside of the installed pipe.” No other I-Code in this corpus defines it, so the IPC 2009 definition is the one to work from. The term is used in 4 chapters of this corpus, most often in Sanitary Drainage (IRC 2009), Definitions (IPC 2009), Sanitary Drainage (IPC 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?
Drainage Fittings — IPC 2009, Definitions:
Type of fitting or fittings utilized in the drainage system. Drainage fittings are similar to cast-iron fittings, except that instead of having a bell and spigot, drainage fittings are recessed and tapped to eliminate ridges on the inside of the installed pipe.
What must be verified before using this guidance?
Drainage Fittings is defined once in this corpus, in the Definitions chapter of the International Plumbing Code (IPC) 2009:
Type of fitting or fittings utilized in the drainage system. Drainage fittings are similar to cast-iron fittings, except that instead of having a bell and spigot, drainage fittings are recessed and tapped to eliminate ridges on the inside of the installed pipe.
Where drainage fittings is used in the code
The term appears in 4 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.
| Chapter | Code | Mentions |
|---|---|---|
| Sanitary Drainage | IRC 2009 | 8 |
| Definitions | IPC 2009 | 3 |
| Sanitary Drainage | IPC 2009 | 3 |
| Definitions | IRC 2009 | 1 |
The term in use
How the code actually writes about drainage fittings, quoted from the 2009 text hosted here:
Drainage fittings shall have a smooth interior waterway of the same diameter as the piping served.
In multiple installations, the connections between a bedpan washer local vent and a local vent stack shall be made with tee or tee-wye sanitary pattern drainage fittings installed in an upright position.
The terms drainage fittings 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 drainage fittings covers:
- Drainage System — IPC 2009: Piping within a public or private premise that conveys sewage, rainwater or other liquid wastes to a point of disposal.
- Fitting — IRC 2009: An accessory such as a locknut, bushing or other part of a wiring system that is intended primarily to perform a mechanical rather than an electrical function.
- System — IFC 2009: An assembly of equipment consisting of a tank, container or containers, appurtenances, pumps, compressors and connecting piping.
Drainage Fittings: 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 IPC | Definitions | |
| Re-check the requirement that uses it | Sanitary Drainage (IRC 2009) | |
| Re-check the requirement that uses it | Definitions (IPC 2009) | |
| Re-check the requirement that uses it | Sanitary Drainage (IPC 2009) | |
| Re-check the requirement that uses it | Definitions (IRC 2009) | |
| Confirm the dependent definition | Drainage System | |
| Confirm the dependent definition | Fitting | |
| Confirm the dependent definition | System | |
| 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
- Drainage System: Building Code Definition
- Fitting: Building Code Definition
- System: Building Code Definition
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 drainage fittings?
The International Plumbing Code (IPC) 2009 defines it in Definitions as: “Type of fitting or fittings utilized in the drainage system. Drainage fittings are similar to cast-iron fittings, except that instead of having a bell and spigot, drainage fittings are recessed and tapped to eliminate ridges on the inside of the installed pipe.” 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 drainage fittings?
In this corpus the term is used across 4 chapters, led by Sanitary Drainage 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 are the 6 mandatory requirements for a drainage system?
Drainage System is a separate defined term. The IPC 2009 defines it as: “Piping within a public or private premise that conveys sewage, rainwater or other liquid wastes to a point of disposal. A drainage system does not include the mains of a public sewer system or a private or public sewage treatment or disposal plant.” That is not the same as drainage fittings, which the IPC 2009 defines as “Type of fitting or fittings utilized in the drainage system. Drainage fittings are similar to cast-iron fittings, except that instead of having a bell and spigot, drainage fittings are recessed and tapped to eliminate ridges on the inside of the …” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.
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