Thermowell

A thermowell is a tubular protective sleeve fitted over a thermocouple's sheathed probe; the thermocouple core is housed inside the sleeve, isolating the temperature-sensing element from direct contact with the medium being measured.
Mechanical protection: Resists fluid erosion, material impact, solid abrasion, and high-pressure surges, preventing probe bending or damage.
Corrosion and temperature resistance: Isolates the probe from high-temperature flue gas, acidic or alkaline liquids, oils, and corrosive gases, preventing thermocouple corrosion and oxidation. Available materials include SS304, SS316, SS321, and Inconel 600. Common configurations include straight, tapered, flanged, threaded, and weld-in types. Standard thread sizes include NPT 1/2, M20×1.5, and G 1/2.
Thermowell applications:
1. Industrial heating equipment
Temperature measurement protection for air duct heaters, tubular heating furnaces, molten salt furnaces, and hot-air circulation ovens.
2. Chemical, oil & gas, and pressure vessel industries
Temperature monitoring for liquids and gases in pipelines and inside reaction vessels; standard equipment for temperature measurement points involving high-pressure, flammable/explosive, or corrosive media.
3. Metallurgy and heat treatment industries
High-temperature flue gas protection for quenching, tempering, sintering, and forging furnaces; resistance to high-temperature oxidation and dust erosion.
6. Boilers and power plant heating systems
Temperature monitoring in high-temperature, high-pressure environments such as boiler flues and steam pipelines.

Materials include seamless stainless steel tubing and seamless Inconel high-temperature alloy tubing; argon arc welding is used for joints; flanges and threaded connectors are machined as integral parts of the assembly. Free Thermowell Selection Guidance
We match the thermowell material and wall thickness to the specific application based on medium temperature, pressure, corrosiveness (pH levels), and installation method (threaded, flanged, or welded).
Custom Manufacturing
We offer fully customizable lengths, diameters, wall thicknesses, tapers, and flange dimensions; we provide quick prototyping and handle orders ranging from small batches to large-scale production.
Comprehensive One-Stop Supply
We supply complete packages—including thermowells, thermocouples, terminal boxes, thermocouple plugs, and various heating elements—allowing customers to source all temperature-sensing and heating components from a single provider.
Robust Protection to Extend Thermocouple Lifespan
Shields against corrosive gases, oil contamination, high-temperature oxidation, and fluid erosion; significantly reduces thermocouple wear and replacement frequency, thereby lowering procurement costs.
High-Integrity Welds and Excellent Pressure Sealing
Manufactured using argon arc welding for a seamless, airtight seal free of porosity or cracks; capable of withstanding high-pressure pipeline media without leakage.
Wide Range of Materials and Specifications for All Operating Conditions
Options range from standard stainless steel to high-temperature, corrosion-resistant alloys, suitable for diverse environments—including ambient or high temperatures, standard or high pressures, and neutral or corrosive media.
High-Precision Machining for a Perfect Fit
CNC precision machining ensures accurate threading and dimensions, resulting in a precise fit with thermocouples and terminal boxes, a tight seal upon installation, and stable temperature-sensing response.