3/4-260W 0.260" Bore Diameter Socket-Weld Design Thermowells

Supported Applications

The Omega Series 260W Socket-Weld Design Thermowells are engineered for temperature measurement using standard length ¼" diameter elements. The series is designed to resist corrosion and is specified for use in chemical baths. These thermowells feature color-coded sensors intended for process control applications.

Operating Conditions & Performance

The Series 260W accommodates a socket-weld design with nominal pipe sizes of ¾" or 1", fitting ASA welding fittings and flanges. The internal bore diameter is fixed at 0.260 in (¼"). Pressure ratings are material-dependent and vary by temperature, as defined in the series pressure-temperature table:

• Brass: Rated up to 5000 psi at 70°F; rating decreases with increasing temperature.
• Carbon Steel (C-1018): Rated up to 5200 psi at 70°F, decreasing to 3500 psi at 800°F and 1500 psi at 1000°F.
• A.I.S.I. 304: Rated up to 7000 psi at 70°F; maintains ratings through 600°F (5400 psi) down to 1650 psi at 1200°F.
• A.I.S.I. 316: Rated up to 7000 psi at 70°F and 200°F; decreases to 6100 psi at 800°F, 5100 psi at 1000°F, and 2500 psi at 1200°F.
• Monel: Rated up to 6500 psi at 70°F; decreases to 5300 psi at 600°F and 1500 psi at 1000°F.

The series supports stem lengths (A) of 4, 6, 9, 12, 15, 18, or 24 inches. Insertion lengths (U) are available in increments from 2½ to 22½ inches.

Configuration Options

The Series 260W offers configurable dimensions and materials to match specific process requirements:

• Pipe Size & Shank Diameter: Available in ¾" nominal (1.050" diameter) with a ¾" shank, or 1" nominal (1.315" diameter) with a 7/8" shank.
• Wetted Materials: Standard options include Carbon Steel (C-1018), A.I.S.I. 304, A.I.S.I. 316, and Brass. Other materials are available upon request.
• Insertion Lengths: Configurable in U2½, U4½, U7½, U10½, U13½, U16½, or U22½ inches.
• Stem Lengths: Available as 4, 6, 9, 12, 15, 18, or 24 inches.

Options and Accessories

The series supports several optional configurations to enhance functionality or protection:

• Caps and Chains: Add suffix "-CC" for a 304 SS cap, or "-CC-Brass" for a Brass cap (additional cost).
• Lagging Extensions: Available to permit standard element use; consult Series 260L and 385L lengths.
• Protective Coatings: PFA, Epoxy, and other materials are available upon consultation with Sales.
• Response Rate Enhancement: Use OT-201 Conductive Silicon Paste to increase response rate (see omega.com).

Compatibility Notes

The Series 260W is compatible with OMEGA® NB1, NB2; PR-12, PR-14, and NPT-style probes, as well as DialTemp™ Thermometers. Metric models are available via omega.com.

Key Product Differences

The Series 260W is distinguished by its socket-weld design intended for permanent installation into piping systems using ASA welding fittings or flanges. Model numbers follow the format PipeSize-260W-UInsertLength-MaterialSuffix. For example, a model designated "3/4-260W-U7½-304SS" indicates a ¾" pipe size thermowell with a 7½" insertion length and A.I.S.I. 304 stainless steel construction.

Material selection directly impacts the maximum allowable pressure at elevated temperatures, as detailed in the series-specific rating table. While Carbon Steel offers high strength at lower temperatures (5200 psi at 70°F), it is not rated for service above 1000°F. Conversely, A.I.S.I. 316 maintains a higher pressure rating (2500 psi) at 1200°F compared to Carbon Steel and Monel.

Shank diameter varies by pipe size: the ¾" nominal model utilizes a ¾" shank, while the 1" nominal model uses a 7/8" shank. Both configurations maintain the standard ¼" internal bore for element compatibility.