Leaky Steam Traps

Q: When I drive up to my plant in the mornings I see lots of steam blowing out of the return tank exhaust. This seems like a lot of steam being wasted and it’s sure to be costing me money. Is there some way I can capture all this steam and recycle it?

A: You already have a steam recycling system in place. Your steam traps are designed to draw in condensation and steam from equipment, condense the steam back into hot water, and discharge all of this condensation to your return tank. Once in the return tank, the water is pumped back into the boiler. Since the water is already hot the boiler doesn't need to work as hard to reheat it to the desired temperature.

In this case, there is a large amount of steam blowing out of the exhaust we would recommend checking to see if one or several of the steam traps are malfunctioning. There should be a difference of at least 75 degrees F (23.8 degrees C) from the inlet and discharge line of the trap.

Steam traps can be checked by several different methods. Wax crayons, heat sensitive paper, and laser testers can all be used. Wax crayons are one of the most common. Simply wipe the crayon across the inlet side of the trap. The wax should melt. Wipe the crayon again on the outlet side. Here it should not melt since the outlet side should be at least 75 degrees F (23.8 degrees C) cooler. If the wax melts on the outlet side you have steam leaking through the trap. It should be repaired or replaced.

With laser testers as shown in the images, simply aim and pull the trigger for a digital temperature reading. Repeat this process for each and every steam trap. And most of all, don't forget to check the trap on the main steam header. This trap is quite often the culprit.

Suggested Reading
DLI Silver, Gold, and Premier members may access more information on this topic in the following bulletins available in DLI's Encyclopedia of Drycleaning Online:

  • Technical Operating Information (TOI) 709: Eight Simple Energy Savers