Types of Steam Traps

An effective steam trap maximizes the efficiency of a steam system in three ways:

• It keeps the system filled with dry steam (saturated steam without entrained condensate)
• It removes by-products (condensate and air) from the system that form insulating barriers that prevent efficient and effective heat transfer
• It makes the hot condensate available for recycling, reducing both waterside care and energy costs at the boiler

In our Steam Basics section we learned the many ways that steam differs from condensate and non-condensables. The laws of physics that govern the behavior of these elements are the basis for the variety in steam trap design.

Mechanical traps operate by using the difference in density between steam and condensate. A float within the trap detects the variance in weight between a gas and a liquid.

Thermostatic traps detect the variation in temperature between steam and condensate at the same pressure. The sensing device operates the valve in response to changes in the condensate temperature and pressure.

Thermodynamic Traps use volumetrics and pressure differences that occur when water changes state into gas. These changes act upon the valve directly.

To see a synopsis for the video "Let's Talk Steam Traps," click here.