About me

I have been a Control Valve Technology Specialist for 45 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.

Privacy Policy

I have no way of identifying who views this web site, uses the links or downloads files from it. If you send me an email to the address on the CONTACT page, I will attempt to answer any questions you ask to the best of my ability. The only email I will ever send you is an answer to your question, or if you request it, I will advise you of any changes I make to any of the Excel sheets you have specifically asked for. I normally save questions sent to me and the answers I provide. I do not share any of these emails or email addresses with anyone. I sometimes reference questions I am asked in future articles or papers, but never identify the source of the question. All the files offered for download have been checked by the latest version of Norton Anti-Virus software. There are some links to the web sites of others over which I have no control and would refer you to their privacy policy.







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.
  4. Professional Development training file on Final Control Elements. This is a new tab.

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