Steam Pipe sizing is a crucial aspect of steam system design

Steam Pipe sizing is a crucial aspect of steam system design. This page offers detailed advice on standards, schedules, materials and sizing for various saturated and superheated steam duties.

The objective of the steam distribution system is to supply steam at the correct pressure to the point of use. It follows, therefore, that pressure drop through the distribution system is an important feature.

There are a number of piping standards in existence around the world, but arguably the most global are those derived by the American Society of Mechanical Engineers (ASME) and the American Petroleum Institute (API), where pipes are categorised in schedule numbers.

Pipes for steam systems are commonly manufactured from carbon steel ASTM A106. The same material may be used for condensate lines, although copper tubing is preferred in some industries.

For high temperature superheated steam mains, additional alloying elements, such as chromium and molybdenum, are included to improve tensile strength and creep resistance at high temperatures.

Piping lengths from the factory not exactly cut to length but are normally delivered as:

    Single random length has a length of around 5-7 meter
    Double random length has a length of around 11-13 meter