A steam trap is a device used to discharge condensates and non-condensable gases with a negligible consumption or loss of live steam. Steam traps are nothing more than automatic valves. They open, close or modulate automatically. The three important functions of steam traps are:

Basic operation

The operation of a steam trap depends on the difference in properties between steam and condensate. Since liquid condensate has a much higher density than gaseous steam, it will tend to accumulate at the lowest possible point in the steam system. Steam properties such as density, latent heat, and saturation/boiling point are affected by pressure. Steam traps can be split into three main categories; Mechanical, Thermodynamic, and Thermostatic. Each type uses a different operating principle to remove condensate and non-condensable gases and keep steam in the system. The vast majority of steam traps in current operation are of the mechanical operated design. Steam traps are sized for specific applications based on amount of condensate they can remove, as well as other factors such as the ability to remove air and non-condensable gases.

Types

Steam traps can be split into three major types:

Performance assessment of steam traps

There are basically three methods for the performance assessment of steam traps.