Steam traps are a type of automatic valve that filters out condensed steam and non-condensed steam, such as air without letting steam escape. Steam is used for regularly for heating or as a driving force for mechanical power. Used to ensure that the steam is not wasted in such applications.
Mechanical traps sense the difference in density between steam and condensate. Condensate from this type of trap is continually discharged, leaving none to the process. These are the most commonly used steam traps utilised today in systems that require large discharge capacities.
Bucket traps use an inverted bucket as a float device that releases the condensate once the bucket to loses buoyancy and sinks, opening the valve allowing the condensate to be released.
A floating ball trap is a simple mechanical trap that uses the weight of the ball, which acts as a lever keeping the valve closed. As condensate enters the trap it raises the float, opening the valve releasing the condensate.
Thermostatic traps utilise a temperature sensing element to determine when to discharge the condensate.
Balanced pressure traps operate by balancing the steam pressure and internal pressure of the thermostatic element. At start-up the valve is open, but once the steam reaches a certain temperature bellow expand to close it. These steam traps can be used in steam tracing applications.
Thermodynamic traps use the difference in velocity between steam and condensate to operate. As steam enters, it can be freely discharged through a valve. When steam reaches the underside of the disc its velocity is much higher than condensate, creating a pressure drop which closes the valve head. The valve stays shut until the steam pressure above the disc drops, allowing the valve to open and the discharge cycle to repeat.
Steam Trap Types
There are three main types of steam traps to consider, these are:
Steam traps can be used anywhere there is a steam system and a need to discharge condensate. These include: