3/4-260L 0.260" Bore Dia Threaded Lagging Extension Thermowells

Supported Applications

The Omega Series 260L is a standard threaded thermowell designed for temperature sensing applications. It accommodates standard length, ¼" stem bimetal thermometers; #20-gage thermocouple elements; unarmored liquid-in-glass test thermometers; and other temperature-sensing elements with a maximum diameter of 0.252".

Documented media compatibility includes water, steam, air, gas, and similar density fluids.

Operating Conditions & Performance

The Series 260L features a ¼" (0.250") probe diameter with an internal bore of 0.260". Insertion lengths range from 2½" to 19½", while stem lengths vary between 6" and 24" depending on the specific model configuration.

Maximum fluid velocity limits are provided in feet per second (fps) based on well type, material, and insertion length. For shorter insertion lengths, values in parentheses represent safe velocities for water flow considering velocity pressure effects; unbracketed values apply to steam, air, gas, and similar density fluids.

Configuration Options

The series is configurable across multiple dimensions including process connection size, wetted material, insertion length, stem length, lagging extension, and shank diameter. PFA coating is available as an option.

• Process Connections: Threaded (NPT) in ½ NPSMT, ¾ NPT, or 1 NPT sizes.
• Wetted Materials: Brass (ASTM B-16), Carbon Steel (C-1018), Stainless Steel A.I.S.I. 304 and A.I.S.I. 316, and Monel®.
• Lagging Extension Type: Designed with a lagging extension to accommodate insulation thickness; specific dimensions vary by model (e.g., T + 1 ¾" wrench allowance).
• Cap Options: Brass cap available via suffix "-CC-Brass"; 304 SS cap available via suffix "-CC".

Model numbers follow the format: Ext Thread P - Model Number - Stem Length A - Insert Length U - Lag Ext T - Shank Dia. Q (example: 3/4-260L-U71/2-304SS).

Key Product Differences

Variants differ primarily by the external thread size, insertion length, stem length, and material selection.
• Thread Sizes: Available in ½ NPT, ¾ NPT, and 1 NPT configurations.
• Insertion Lengths (U): Options include 2½", 4½", 7½", 10½", 13½", and 19½".
• Stem Lengths (A): Corresponding stem lengths range from 6" to 24" based on the insertion length selected.
• Lagging Extension (T): Typically 3", with a 2" extension available for shorter models.
• Shank Diameter (Q): Varies by model, including sizes such as —, ¼", ⅜", and ¾" depending on the thread size and insertion length combination.