Study Guides/Learn/Difference Between Pipe and Tube
Study Guide · Learn

Difference Between Pipe and Tube

The words 'pipe' and 'tube' are often used to mean the same thing, but in engineering they are different. Both are hollow, round sections, but they differ mainly in how they are measured and what they are used for. A pipe is usually measured by its inside diameter (the bore) and is mainly used to carry fluids like water, gas and oil. A tube is usually measured by its outside diameter and is mainly used for structural and mechanical purposes where exact size and strength matter. This guide explains the difference between a pipe and a tube.

Question (Click to Flip)

What is the difference between a pipe and a tube?

Answer

A pipe is measured by its inside diameter (nominal bore) and is mainly used to carry fluids like water, gas and oil. A tube is measured by its outside diameter and wall thickness, is made to tighter tolerances, and is mainly used for structural and mechanical purposes. In short, a pipe focuses on flow capacity, while a tube focuses on exact size and strength.

Card 1 of 3 free previews

Key Facts

A pipe is mainly used to carry fluids; a tube is mainly used for structural purposes.

A pipe is measured by its inside diameter (nominal bore).

A tube is measured by its outside diameter (OD) and wall thickness.

Pipe wall thickness is described by a 'schedule' number.

Tubes are made to more precise (tighter) tolerances than pipes.

Pipes are usually round; tubes can be round, square, rectangular or oval.

For pipes, flow capacity matters; for tubes, strength and exact size matter.

What is a Pipe?

A pipe is a hollow, round section that is mainly used to carry (transport) fluids such as water, gas, steam and oil.

Features: • It is measured by its nominal bore (roughly the inside diameter). • The inside diameter is important because it decides how much fluid can flow through it. • Its wall thickness is given by a 'schedule' number. • It is usually available in standard sizes. • It is mostly round in shape.

So, for a pipe, what matters most is the flow capacity, which depends on the inside diameter.

What is a Tube?

A tube is a hollow section that is mainly used for structural, mechanical and instrumentation purposes, where exact dimensions and strength are important.

Features: • It is measured by its outside diameter (OD) and wall thickness. • The outside diameter is important because tubes are often fitted into other parts. • It is made to closer (more precise) tolerances than pipes. • It can be round, square, rectangular or oval in shape. • It is used in structures, frames, furniture, heat exchangers and machines.

So, for a tube, what matters most is the exact outside size and strength.

Difference Between Pipe and Tube

Pipe: • Measured by inside diameter (nominal bore) • Mainly used to carry fluids (water, gas, oil) • Wall thickness given by 'schedule' • Less strict (looser) tolerances • Usually round in shape • Flow capacity is the main concern

Tube: • Measured by outside diameter (OD) and wall thickness • Mainly used for structural and mechanical purposes • Made to precise (tight) tolerances • Can be round, square, rectangular or oval • Strength and exact size are the main concern

In short, a pipe is for carrying fluids and is measured by its bore, while a tube is for structural use and is measured by its outside diameter.

Questions and Answers

What is the difference between a pipe and a tube?+

A pipe is measured by its inside diameter (nominal bore) and is mainly used to carry fluids like water, gas and oil. A tube is measured by its outside diameter and wall thickness, is made to tighter tolerances, and is mainly used for structural and mechanical purposes. In short, a pipe focuses on flow capacity, while a tube focuses on exact size and strength.

How is a pipe measured?+

A pipe is measured by its nominal bore, which is roughly its inside diameter, because the inside diameter decides how much fluid can flow through it. Its wall thickness is described by a 'schedule' number. The flow capacity is the main concern for a pipe.

How is a tube measured?+

A tube is measured by its outside diameter (OD) along with its wall thickness, because tubes are often fitted into other parts where the exact outer size matters. Tubes are made to precise tolerances and can be round, square, rectangular or oval in shape.

Are pipe and tube the same thing?+

In everyday language they are often used to mean the same thing, but in engineering they are different. A pipe is mainly for carrying fluids and is measured by its inside diameter, while a tube is mainly for structural use and is measured by its outside diameter, with more precise dimensions.

More in Learn

Study Smarter with Shinyu.ai

Turn this guide into revision flashcards, a practice exam, or an AI-generated podcast — free, no signup required.