About me

I have been a Control Valve Technology Specialist for 35 years and over that time I have gained a lot of insight into the proper application of control valves. I recently retired, but can't bring myself to completely divorce myself from the world of control valves.

Jon Monsen, PhD, PE OR (Ret.), CA, WA


The Author has made a reasonable effort to ensure the accuracy of the information herein. However, the information contained on this site is provided without any representation or warranty as to accuracy or completeness or otherwise and should be used only as a general guideline and not as an authoritative source of technical information. The Author is not offering the information as engineering or other professional services or advice. This site does not constitute an offer or solicitation to perform professional engineering services.

About this site

I have gathered various information onto this site in the hope that it will be useful to someone. There are separate pages for:

  1.  Excel® worksheets that perform calculations that might be of use to those who deal with or apply control valves. Included are valve sizing worksheets
  2.  Links to articles I have written on the subject of control valve application
  3. Books I have written or recommend.

Subjects that are addressed include:

  • Nelprof® 6 sizing software Step-by-Step Guide
  • Control valve sizing
  • Control valve noise
  • Cavitation in control valves
  • Liquid vapor pressure
  • Gas compressibility factor
  • Determining the pressure drop to use in a valve sizing calculation
  • Control valve installed gain
  • Control valve flow characteristics