Stainless Steel Thermowell is a specialized component used in temperature measurement applications to protect temperature sensors, such as thermocouples or RTDs (resistance temperature detectors), from the process fluid or gas being measured. Stainless steel is a common material used in thermowell due to its corrosion resistance and durability. The Stainless Steel thermowell is a hollow tube that is inserted into the process stream and typically welded onto a piping system.