Threaded Thermowells are common to all types of low pressure, low temperature industrial applications. They can also be installed in higher pressure, higher temperature applications where appropriate installation considerations are made. Threaded thermowells are often threaded into a threaded branch outlet connector which is itself welded to the process. In some cases the threaded thermowell may be threaded directly into a tapped pipe or other structure.
Threaded thermowells most commonly connect by means of a tapered thread (ex: NPT thread), but machined thread, SAE and other thread styles are also common in industry. Where a tapered thread is installed the threads themselves should have a sufficient number of threads of engagement to hold pressure. Welding applied is typically not to hold pressure but to prevent the thermowell from backing out.
If desired, wake frequency calculations per ASME/ANSI PTC 19.3TW can be performed on these products using JMS’s free SwiftyCalc software.