Introduction to Steam

  1. Steam Traps Management

     
    1. The purpose of steam traps management

 

    1. Although steam traps are always installed in steam systems, depending on the size of each factory, the number of installed steam traps shall be different. For example, in case of small-scale laundry facilities or food factories, this may be from a few to dozens, and the number of steam traps can be as many as 20,000 or more in large petroleum refining plants. The operating hours vary from batch operation in process equipment to seasonal operation and continuous operation (24/7). During the process of using any device, the performance degrades, and breaks down. However, as steam traps are used in an environment where pressure is much higher than atmospheric pressure and temperature is well over 100 ℃, Thus, it is the device used in very severe environments.

       

      Steam traps generally fail in one of two ways.

       
      • Steam leaks

      • Clogging

 

 

    1. Steam leaks

 

 

Steam leaks are a problem in which the valve and the valve seat inside the steam trap are corroded by fluid (cavitation), and a gap is formed through which steam flows out. Once steam leak occurs, steam with high energy flows into the gap of valve at high speed, and the deterioration progresses. In addition, steam leak may occur because the valve is blocked by small debris. In this case, the valve may deteriorate due to a sudden steam leak, or it may return to normal operation by blowing away the trapped debris when the condensate is discharged.

 

 

    1. Blockage

 

 

The main cause of a blockage is the accumulation of scale in the piping at the valve or the clogging of the strainer screen with dust or scale. If the valve is completely clogged (blocked), the condensate will accumulate inside the steam traps’ primary equipment, causing the equipment malfunction or water hammer.

 

 

In this way, a defective steam trap will lead to the waste of the original steam or decrease performance of the production equipment and equipment performance. Thus, it is necessary to maintain and exchange failed steam traps through constant surveying of steam traps. It is estimated in factories in which steam traps are not maintained, that the failure rate is around 30-40%. On the other hand, effective maintenance can keep the steam trap failure rate at around 3-5 %. In large factories, in which a lot of steam traps are installed, this can make a difference of tens of millions of yen to more than 100 million yen per year, even looking only at loss caused by steam leakage.

 

Periodic steam traps surveys are generally performed annually for the whole facility.