Above are five different types of steam traps. Which one is the Inverted Bucket Steam Trap?
And the answer is…
D. The Inverted Bucket Steam Trap
The inverted submerged bucket steam trap is a mechanical trap that operates on the difference in density between steam and water. Steam entering the inverted submerged bucket causes the bucket to float and close the discharge valve. Condensate entering the trap changes the bucket to a weight that sinks and opens the trap valve to discharge the condensate. Unlike other mechanical traps, the inverted bucket also vents air and carbon dioxide continuously at steam temperature.
Here are descriptions of the other steam traps shown:
A. The Control Disc Steam Trap
The controlled disc steam trap is a time-delayed device that operates on the velocity principle. It contains only one moving part, the disc itself. Because it is very lightweight and compact, the CD trap meets the needs of many applications where space is limited. In addition to the disc trap’s simplicity and small size, it also offers advantages such as resistance to hydraulic shock, the complete discharge of all condensate when open and intermittent operation for a steady purging action.
B. The Float and Thermostatic Steam Trap
The float and thermostatic trap is a mechanical trap that operates on both density and temperature principles. The float valve operates on the density principle: A lever connects the ball float to the valve and seat. Once condensate reaches a certain level in the trap the float rises, opening the orifice and draining condensate.
C. The Bimetallic Steam Trap
Bimetallic steam traps have the ability to handle large start-up loads. As the trap increases in temperature, its stacked nickel-chrome bimetallic elements start to expand, allowing for tight shutoff as steam reaches the trap, thus preventing steam loss. In addition to its light weight and compact size, it offers resistance to water hammer.
E. The Thermostatic Steam Trap
Thermostatic steam traps operate on the difference in temperature between steam and cooled condensate and air. Steam increases the pressure inside the thermostatic element, causing the trap to close. As condensate and non-condensable gases back up in the cooling leg, the temperature begins to drop, and the thermostatic element contracts and opens the valve. The amount of condensate backed up ahead of the trap depends on the load conditions, steam pressure and size of the piping. It is important to note that an accumulation of non-condensable gases can occur behind the condensate backup.
For complete descriptions of each trap as well as instructions on how to trap, download Armstrong’s Steam Conservation Guidelines for Condensate Drainage.