Consulting-Specifying Engineer, Jan./Feb. 2014, by David Grassl, PE.
http://www.csemag.com/single-article/don-t-blow-your-money-on-a-steam-trap/1ea8d3707c39adae4585b425e07b4f31.html

"Steam and condensate leaks cost buildings and industrial plants millions of dollars in lost energy, while increasing emissions from boilers due to increased operation, creating potential safety hazards, and lowering the reliability of operations. This article will review the many factors that impact the reliability, performance, longevity, and maintenance requirements for condensate return piping systems."