what is epm in boilers, condensers, evaporators, feed water tanks

epm meaning = equivalents per million
- a water analysis reporting method in which the results are on an ion basis
- an ion is an atom or molecule with a net electric charge because of gaining or losing electron(s).
- chemical components of analysis are based on a common denominator which is the chemical equivalent weight
- not a commonly accepted standard, not recommended for use in plants
- advantage of this approach is mainly for simplicity of calculation


ppm meaning = parts per million
1 ppm = 0.0001% which is one ten-thousandth of one percent
one part (by weight) per million parts (by weight)
example: 1 kg of salt is dissolved in 1,000,000 kg of water [ 1 ppm salt in water ]
simpler, reliable, commonly accepted standard for water analyses reports
for feed water analysis in boilers, condensers, evaporators, and other steam plant equipment