Significant deposition and corrosion related failures of the steam path in boilers, heat recovery steam generators (HRSGs), steam turbines or process equipment in contact with steam can result if accurate sampling and analysis of saturated, superheated and reheated steam is not carried out. This article reviews the lowest acceptable equipment standards for sampling and on-line analysis of steam from boilers and HRSGs in addition to the need for routine carryover testing. An array of reflective case studies of steam sampling, analysis and purity issues are displayed, highlighting the key lessons.