Steam Trap Working Principle And Selection

Steam trap Working Principle and Selection

The steam trap plays the role of steam blocking and drainage in the steam heating system. Choosing the proper steam trap can make the steam heating equipment reach the highest working efficiency. In order to achieve the most ideal results, it is necessary to fully understand the working performance and characteristics of various types of steam traps.

There are many types of steam traps, each is with different performance. When selecting a steam trap, first select its characteristics to meet the best operation of the steam heating equipment, and then consider other objective conditions, so that the steam trap you need is correct and effective.

The steam trap must be able to "recognize" steam and condensate in order to play a role in steam blocking and drainage. "Identify" steam and condensate are based on three principles: density difference, temperature difference and phase change. Therefore, three types of steam traps were manufactured based on three principles: Mechanical type steam trap, Thermostatic type steam trap, and Thermodynamic type Steam Trap.

The mechanical type Steam Trap is also called the float type, which uses the difference in the density of condensate and steam to change the level of the condensate, so that the float rises and falls to drive the valve flap to open or close to achieve the purpose of steam blocking and drainage. The mechanical type steam trap has a small degree of supercooling and is not affected by changes in working pressure and temperature. If there is water, it is discharged, and there is no water in the heating equipment, which can make the heating equipment achieve the best heat exchange efficiency. The maximum back pressure rate is 80%, and the working quality is high. It is the most ideal trap for production process heating equipment.

Mechanical Steam traps include free float type, free Semi-float type, lever float type, inverted bucket type, etc.

Thermostatic steam traps use the temperature difference between steam and condensate to cause the deformation or expansion of the temperature sensing element to drive the valve core to open and close the valve. The supercooling degree of the thermostatic trap is relatively large, generally the supercooling degree is 15 degrees to 40 degrees, it can use part of the sensible heat in the condensed water, there is always high temperature condensate in front of the valve, no steam leakage, and the energy saving effect is remarkable . It is the most ideal steam trap on steam pipelines, heat tracing lines, small heating equipment, heating equipment, and small heating equipment with low temperature requirements.

Thermostatic Steam traps are available in Capsule type Steam Trap, bellows type Steam Trap and Bimetallic type Steam Trap

According to the principle of phase change, thermodynamic traps rely on the different thermodynamic principles of changes in flow rate and volume when steam and condensate pass through, so that different pressure differences are generated across the valve plate, and the valve plate is driven to switch the valve. Because the working power of the thermodynamic steam trap comes from steam, the steam waste is relatively large. The structure is simple, resistant to water hammer, the maximum back is 50%, there is noise, the valve plate works frequently, and the service life is short.

Thermodynamic steam traps include thermodynamic type (disc type) Steam Trap, pulse type Steam Trap and Orifice plate type Steam Trap.