Case Study: Steam Traps

A forest products company in the Northwest U.S. uses the UL101 ultrasound sensor to find failing steam traps. When lumber is cut into size, it is put into a kiln. A steam radiator system is used to control the temperature to cure the lumber. Steam is pumped through a series of radiators to heat up the kiln to about 360 to 370 degrees. If steam turns into condensate, the system is less effective and more steam has to be pumped through the system. Steam costs are even higher than compressed air costs, so it is very important that the steam trap works to return the condensate back to the boiler. If condensate remains in the steam pipes, the system has to work much harder.

Once a month, a potlatch crew checks steam traps and makes repairs. They first look for escaping steam visually, which would adversely affect the production system. Premature steam leaks could be found with the use of the UL101.

When a steam trap is not working properly, more steam is pumped into system to get the end amount of steam required for the kiln. Without the UL101, the steam traps had to be taken apart to inspect for mechanical wear. The UL101 is used in contact mode to listen for trap operation. If the steam trap is operating, the user will hear a roar. If steam trap is not cycling, there is silence. As it cycles there is a roar, silence, roar. If nothing can be heard, the trap is stuck closed.

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