Steam traps are critical equipment for energy efficiency in various industrial facilities that use steam and steam lines intensively. Our study explains the types of steam traps, usage features, and issues in applications (such as montage, sizing, material compatibility, and working conditions) that lead to some common steam trap problems. The general causes of steam trap problems, methods of maintenance and fixing with where to pay attention are explained in detail. With the leakage measurements of steam lines of an industrial facility, the energy loss cost of steam traps and their fixing and maintenance costs are calculated, illustrating their economic importance. As a result of the analysis, one-year energy loss cost from the steam traps of the factory with 105 steam traps was determined to be 375,842 USD.