Emerson
The Rosemount Twisted Square thermowell (photo) is said to reduce dynamic stress, simplify process calculations and provide more accurate temperature measurements than other thermowells on the market. Twisted Square thermowells improve reliability and reduce risk of fatigue failure through their ability to dampen dynamic stresses caused by oscillating vortex pressures. These dynamic stresses can result in vortex-induced vibration (VIV), which is the primary source of thermowell stress failures. The new design is said to reduce VIV by over 90%. This helps to simplify process calculations by eliminating the need to size thermowells to reduce dynamic and frequency limits, thereby saving engineering time and lowering costs without requiring design changes. It is suitable for use where conventional thermowells fail to meet the ASME PTC 19.3 TW standard for safe and reliable thermowell design. — Emerson, St. Louis, Mo.