Updated 2026-09-07

Building Code Glossary

Discharge Pipe: Building Code Definition

How the IPC 2009 define discharge pipe, 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.

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Direct answer

Discharge pipe is a defined term in the International Plumbing Code (IPC) 2009, in Definitions. The code's own words are: “A pipe that conveys the discharges from plumbing fixtures or appliances.” 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 10 chapters of this corpus, most often in Building Services and Systems (IFC 2009), Sanitary Drainage (IPC 2009), Water Heaters (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?

Discharge Pipe — IPC 2009, Definitions:

A pipe that conveys the discharges from plumbing fixtures or appliances.

Labeled code-term definition diagram: Discharge Pipe: Building Code Definition — How the IPC 2009 define discharge pipe, where the wording differs, and which chapters depend on the term.

What must be verified before using this guidance?

Discharge Pipe is defined once in this corpus, in the Definitions chapter of the International Plumbing Code (IPC) 2009:

A pipe that conveys the discharges from plumbing fixtures or appliances.

Where discharge pipe is used in the code

The term appears in 10 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

Chapter	Code	Mentions
Building Services and Systems	IFC 2009	4
Sanitary Drainage	IPC 2009	3
Water Heaters	IRC 2009	3
Boilers, Water Heaters and Pressure Vessels	IMC 2009	2
Exhaust Systems	IMC 2009	2
Water Supply and Distribution	IPC 2009	2
Plumbing Fixtures	IRC 2009	2
Definitions	IPC 2009	1
Definitions	IRC 2009	1
Sanitary Drainage	IRC 2009	1

The term in use

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

Ammonia diffusion systems shall include a tank containing 1 gallon of water for each pound of ammonia (4 L of water for each 1 kg of ammonia) that will be released in 1 hour from the largest relief device connected to the discharge pipe.

— IFC 2009 §606.12.6

Such valves shall be located above the sump cover required by Section 712.1 or, where the discharge pipe from the ejector is below grade, the valves shall be accessibly located outside the sump below grade in an access pit with a removable access cover.

— IPC 2009 §712.2

The discharge pipe shall be the same diameter as the safety or relief valve outlet.

— IMC 2009 §1006.6

The terms discharge pipe is built out of

The definition above leans on 1 other defined term. Each carries its own code definition, and a local amendment to any of them changes what discharge pipe covers:

Plumbing — IRC 2009: For the purpose of this code, plumbing refers to those installations, repairs, maintenance and alterations regulated by Chapters 25 through 33.

Discharge Pipe: 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	Building Services and Systems (IFC 2009)
Re-check the requirement that uses it	Sanitary Drainage (IPC 2009)
Re-check the requirement that uses it	Water Heaters (IRC 2009)
Re-check the requirement that uses it	Boilers, Water Heaters and Pressure Vessels (IMC 2009)
Confirm the dependent definition	Plumbing
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 discharge pipe?

The International Plumbing Code (IPC) 2009 defines it in Definitions as: “A pipe that conveys the discharges from plumbing fixtures or appliances.” 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 discharge pipe?

In this corpus the term is used across 10 chapters, led by Building Services and Systems 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 are the building code rules for condensate discharge in Florida?

Condensate is a separate defined term. The IRC 2009 defines it as: “The liquid that separates from a gas due to a reduction in temperature, e.g., water that condenses from flue gases and water that condenses from air circulating through the cooling coil in air conditioning equipment.” That is not the same as discharge pipe, which the IPC 2009 defines as “A pipe that conveys the discharges from plumbing fixtures or appliances.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

What is the code for a water heater discharge pipe?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IPC 2009 states, in Definitions: “A pipe that conveys the discharges from plumbing fixtures or appliances.” It is defined in IPC 2009. It is not the same as Water Heater, which the IRC 2009 defines separately as “Any heating appliance or equipment that heats potable water and supplies such water to the potable hot water distribution system.” 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.

What is a discharge pipe?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IPC 2009 states, in Definitions: “A pipe that conveys the discharges from plumbing fixtures or appliances.” It is defined in IPC 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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