Emerson Provides Online Resource Tool for PTC 19.3 TW

Thermowells, a circular cylinder installed like a cantilever inside process piping, provide process condition protection and a process seal for temperature sensors. ASME PTC 19.3-1974 has been the standard by which most thermowells were designed, but it has had its problems. A new standard, PTC 19.3TW, has just been approved and Emerson Process Management has created an online resource for understanding the changes.

The Thermowell Calculation Tool web site includes a video explanation of the new standard, whitepaper describing its history and application, and tools to help users comply with the new standard. A free online tool, for example, can provide a preliminary calculation that gives an immediate pass/fail score. More in-depth calculations are available via Emerson’s R21 report function.

Emerson makes and sells Rosemount brand thermowells. Starting in 2010, Emerson joined other vendors, users, agencies and academia to help the American Society for Mechanical Engineers (ASME) update the thermowell calculation standard from PTC 19.3 to PTC 19.3 TW. According to an Emerson spokesperson, the Emerson expert calculation team has performed more than 35,000 thermowell calculations a year since then.

 “We perform a calculation with the requested thermowell geometry, material and process conditions. If the design doesn’t meet ASME requirements, we’ll make recommendations for achieving an acceptable outcome,” said the spokesperson. “We use industry-standard ASME material properties in every calculation so you are ensured of consistent and correct results. In addition, all Rosemount thermowells are manufactured with these properties, so you are guaranteed the report will match your thermowell.”