1-260HL 0.260" Bore Dia Threaded Heavy Duty Lagging Thermowells
Heavy Duty Threaded Thermowell for 1/4 Inch Diameter Elements
Supported Applications
The Omega Series 260HL is a heavy-duty threaded thermowell designed for temperature sensing applications. It accommodates standard length, ¼" 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. The series is manufactured in the USA.
Operating Conditions & Performance
The Series 260HL features a threaded process connection available in standard sizes of 3/4 NPT and 1 NPT; other thread sizes are available upon request. Internal pipe threads (NPSM) accept both NPT and NPS male threads.
Maximum fluid velocity limits vary by material, insertion length, and media type as defined in the specification tables:
• Brass (ASTM B-16): Velocity ratings range from 305 ft/s for a 2½" insertion to lower values at greater lengths.
• Carbon Steel (C-1018): Ratings begin at 386 ft/s for the shortest insertion length.
• A.I.S.I. 304 & A.I.S.I. 316 Stainless Steel: Maximum velocity starts at 440 ft/s for a 2½" insertion on the ¾" model.
• Monel®: Ratings begin at 354 ft/s for the shortest insertion length.
Note: In maximum fluid velocity data, values in parentheses are safe for water flow; unbracketed values apply to steam, air, gas, and similar density fluids. Pressure-temperature ratings require consultation of omega.com resources.
Configuration Options
The series supports a configurable envelope across wetted materials, insertion lengths, stem lengths, and shank diameters. Selection is driven by the specific process connection size (3/4 NPT or 1 NPT) and dimensional requirements.
• Wetted Materials: Brass (ASTM B-16), Carbon Steel (C-1018), Stainless Steel A.I.S.I. 304, Stainless Steel A.I.S.I. 316, and Monel®.
• Insertion Lengths (U): Available in increments including 2½", 4½", 7½", 10½", 13½", and 19½" inches.
• Stem Lengths (A): Configurable options include 6, 9, 12, 15, 18, and 24 inches.
• Lagging Extension: The series includes a lagging extension type with specific allowances for wrench clearance and thread allowance as detailed in the ordering guide.
Additional options include cap and chain configurations: add suffix '-CC-Brass' for brass caps or '-CC' for 304SS caps (additional cost). PFA coating is available via omega.com. Metric models are also offered.
Key Product Differences
Variants within the Series 260HL differ primarily by process connection size, material composition, and dimensional configuration:
• Process Connection Size: Models begin with '3/4' for ¾" NPT or '1' for 1" NPT connections.
• Material Suffixes: Model numbers specify material as '-BRASS', '-CS' (Carbon Steel), '-304SS', or '-316SS'. Monel® is available but requires specific ordering guidance via omega.com.
• Dimensional Codes: The model number structure follows the pattern: Ext Thread P - Model Number - Lag Ext. T - Stem Lgth A - Insert Lgth U - Shank Dia Q (e.g., 3/4-260HL-U71/2-304SS).
Shank diameter (Q) varies by insertion length; for example, the ¾" NPT series lists a shank diameter of "—" for the 2½" insertion and 7/8" for insertions from 4½" to 19½". The 1" NPT series uses a 1¼" shank diameter for longer insertions.