STEAM TRAPS Steam traps are designed to retain the steam in a radiator or other using device until it changes into condensate. After the steam has turned into condensate, the trap releases the water so it can enter the return lines. However, it keeps the steam coming into the radiator from escaping. The trap performs an important function, since the excessive accumulation of water prevents the proper heating of the radiator or other steam equipment. Also, steam that is permitted to blow through a defective trap results in heat loss.Types of Traps Traps are generally classified according to their operation. The most common types of traps are float, bucket thermostatic, float thermostatic, impulse, thermodynamic, throttling, and bimetallic element.

FLOAT TRAP The float trap normally consists of a body, float, linkage, seat, and valve. As water enters the trap, the float rises, opens the valve, and allows the accumulation of water to flow into the return lines that take it to the boiler. When the water has run out, the float falls, closes the valve, and traps the steam. The maintenance to be done on a float trap is of a simple nature. One of the most common difficulties is that of the float getting water in it and not rising. In this case, the float must be replaced. The valve sometimes gets plugged or worn and has to be cleaned or replaced.

BALL-FLOAT TRAP In a ball-float trap, the valve of the trap is connected to the float so the valve opens when the float rises. When the trap is in operation, the steam and water that may be mixed with it flow into the float chamber. As the water level rises, the float is lifted, there by lifting the valve plug and opening the valve. The condensate drains out and the float moves down to a lower position, closes the valve. The condensate that passes out of the trap is returned to the feed system.