MBH-Nozzle

Supported Applications

The Omega MBH Nozzle series comprises DuraBand® band heaters with built-in straps designed for heating cylindrical surfaces in industrial applications. The product overview identifies typical uses including plastic injection molding machines, extruders, oil reclamation equipment, and food processing machinery.

Operating Conditions & Performance

The series features a specially treated rust-resistant steel sheath casing with mica insulation and nickel-chrome resistance ribbon wire. The maximum operating temperature for the standard sheath is 482°C (900°F). Electrical ratings support a maximum voltage of 480 Vac, with dual voltage or 3-phase availability depending on heater design.

Performance specifications include:

• Nominal Watt Density: 3 to 7 Watt/cm² (20 to 45 Watt/in²)
• Maximum Watt Density: Dependent on heater size and operating temperature
• Resistance Tolerance: 10%, -5%
• Wattage Tolerance: 5%, -10%

A caution note states that failure to adhere to the maximum allowable watt density per heater size will result in poor operating life.

Configuration Options

The MBH Nozzle series is offered in various construction styles, including one-piece bands, two-piece bands, and one-piece expandable bands. Clamping variations include standard built-in strap, wedge lock, and separate straps configurations.

Construction Styles and Minimum Dimensions:

• Type NB (One-Piece Band): 50.8 mm (2") minimum ID; 31.8 mm (1¼") minimum width
• Type NS (Two-Piece Band): 76.2 mm (3") minimum ID; 31.8 mm (1¼") minimum width
• Type NE (One-Piece Expandable Band): 63.5 mm (2½") minimum ID; 31.8 mm (1¼") minimum width
• Type TWL (Wedge Lock One-Piece Band): 25.4 mm (1") minimum ID; 25.4 mm (1") to 88.9 mm (3½") maximum width
• Separate Strap Styles: Minimum IDs range from 22.2 mm (7/8") for Type SB to 63.5 mm (2½") for Type SE; minimum widths are 19.1 mm (¾") or 31.8 mm (1¼").

Electrical Connections:

• General purpose terminal box with a 13 mm (1/2") trade size knockout (actual diameter 22 mm (7/8")) for standard conduit or flexible armor cable connectors.
• Screw terminals: 8-32 UNF—20 Amp; 10-32 UNF—25 Amp.
• Lead wire termination: 10 Amp.

Physical Construction Limits:

• Minimum Width: 19.1 mm (¾")
• Width Tolerance: 1.59 mm (±1/16")
• Nominal Gap: 9.5 mm (³/₈"); larger gaps for probes or thermocouples must be specified when ordering.

Built-In Brackets: The number of built-in brackets varies by heater width, ranging from one bracket for widths between 38 to 76 mm (1½ to 3") up to five brackets for widths between 257 to 381 mm (10¼ to 15").

Key Product Differences

The series distinguishes itself through specific construction and clamping variations. One-piece bands are available in standard, expandable, and wedge lock configurations. Two-piece bands offer alternative mounting for larger diameters or restricted access areas.

• Built-In Strap: Standard configuration featuring a unique built-in strap for superior clamping with torque-resistant screw terminals.
• Wedge Lock (Type TWL): A one-piece band style available from 25.4 mm (1") minimum ID up to an 88.9 mm (3½") maximum width.
• Separate Straps: Styles SB, SS, and SE utilize separate straps for clamping rather than a built-in strap mechanism.

A note specifies that the one-piece expandable band should not be opened and closed more than twice. Additionally, unheated areas must be subtracted from calculations: 1" × width for one-piece bands; 2" × width for two-piece bands; and Size + ½" × width for holes and cutouts.