Steam Systems - Piping Systems
October 21, 2002

Introduction

The design of steam piping systems is generally covered by the following codes and standards:

ASME B31.1     Power Piping

ASME B16.5    Pipe Flanges and Flanged Fittings

ASME B16.34     Valves-Flanged, Threaded, and Welding End

Steam Line Sizing

It is important that the steam generated in the boiler arrives at the end user at the desired pressure.  Steam lines should be sized to ensure that the line losses are not excessive.  Velocities should also not be too high as this can lead to excessive noise being generated.  The following criteria can be used for sizing main steam lines.

• High pressure: 2 to 3 psig/100 ft
• Medium pressure: 1 psig/100 ft
• Low pressure: 0.5 psig/100 ft

Specification and Materials