Print this page

Thermowells and Protection Tubes

Thermowells and protection tubes are designed to allow for uninterrupted servicing of temperature sensors without opening pressurized lines or tanks. They also protect the sensors from hostile environments where they may otherwise fail from corrosive, abrasive or pressurized systems.

  • Also called "drilled wells", thermowells are manufactured from drilled bar stock using various materials and alloys, and may be coated to protect against corrosive mediums.
  • Many thermowell types have different process connection options available, including threaded, flanged, weld in, socket weld and Van Stone wells
  • Metal protection tubes (pipe wells) are manufactured from seamless pipe of various pipe sizes and alloys (see "Material Selection Guide"). Can be supplied with or without process threads or a flange
  • Ceramic protection tubes are used for high temperature applications (above 2200°F 1205°C), such as with a type R thermocouple

For "drilled wells," instrument connection is 1/2"-14 NPT. The length below the threads of the flange is considered the stem, immersion length or "U" length. Proper consideration should be given to temperature, flow, pressure and environment when choosing the correct thermowell type.


Material selection guide

contact us