Instrumentation

Temperature Thermowells

Technology

Thermowells are basically brought into use for creating isolation between temperature sensing element and its immediate environment which can be either in the form of liquid or gas or slurry. The main purpose of a thermowell is to protect the temperature sensor to insure long life and accurate measurement. Maintenance is aided by allowing the sensor to be removed without having to drain the pipe or tank. Sensor changes can be done on the fly. There are many variations of two basic kinds; low pressure and high pressure. They are used to provide an isolation between a temperature sensor and the environment, either liquid, gas or slurry. A thermowell allows the temperature sensor to be removed and replaced without compromising either the ambient region or the process. Thermowell types are designated by the style of stem or wetted portion of the well. Thermowells are available in a variety of materials, along with a wide variety of thread or flange fittings depending on your installation requirements. Most thermowells are machined from bar stock to insure integrity for high pressure applications. Flanges are joined to a thermowell stem most commonly by a welding process. Smaller wells may be constructed from tubing and have the end welded closed and a process connection welded on.

Manufacturers

Endress + Hauser offers 28 different variations of thermowell products, some of which are made of drilled barstock material, allowing them to be used in heavy duty or general purpose applications. Website
SOR Inc. manufactures multiple types of thermowells and protection tubes with a variety of materials and process connections for both. All metallic wells are constructed in strict compliance with ASTM and ANSI specifications. Ceramic protection tubes are available for high temperature thermowells. Fluid flowing by a thermowell forms a turbulent wake that has a defined frequency. Website
United Electric Controls is a leading manufacturer of custom made thermowells. They offer a complete line of sold-bore thermowells in a variety of materials and constructions. Serving customers worldwide, their professional engineering and production teams collaborate with process and design engineers to manufacture products that meet the most challenging demands of the food and beverage, dairy, nuclear, military, petrochemical, pharmaceutical, and oil and gas industries. Website