Tubular Heaters
Tubular Element & Assembly Selection Guide
The chart will help you select an appropriate heater based on your application and watt density restrictions. These charts are application driven. The total wattage required by your application should be known before selecting a specific heater type(s) from Watlow stock. If your required wattage is not known, please contact your Watlow representative.
FIREBAR® Single/Double-Ended Heaters
FIREBAR heating elements provide added heating performance over standard round tubular heating elements—especially for immersion applications in petroleum-based liquids requiring high kilowatts.
The FIREBAR's unique flat surface geometry packs more power in shorter elements and assemblies, along with a host of other performance improvements. These include:
-Minimizing coking and fluid degrading
-Enhancing the flow of fluid past the element's surface to carry heat from the sheath
-Improving heat transfer with a significantly larger boundary layer allowing much more liquid to flow up and across the sheath's surface
FIREBAR elements are available in single- and double-ended constructions with one inch or 5⁄8 inch heights. These two configuration variables make it possible to use FIREBAR elements instead of round tubular elements in virtually all applications.
FINBAR is a special version of the one inch, single-ended FIREBAR. FINBAR is specially modified with fins to further increase surface area for air and gas heating applications.
High-Temperature Tubular Heaters
Watlow manufactures high-temperature tubular heaters to bridge the gap between standard tubular heaters and Watlow MULTICELL™ heaters. This high temperature heater is well suited for process air heating applications in excess of 1300˚F (704˚C), resulting in a maximum sheath temperature of 1800˚F (983˚C). Controlled lab testing between the new design and current tubular designs shows an increase in life of approximately 50 percent.
The high-temperature heaters consist of an engineered tubing with an outer sheath of Alloy 600 and a special internal construction. The outer sheath offers high temperature capabilities, reduced oxidation as well as corrosion resistance.
The tubular heater offering is available in 0.430 and 0.375 inch diameters that are configurable either as formed tubulars or process heaters. The tubular heaters can also be welded to flanges and plates for mounting purposes. Maximum sheath length available is 275 inches for the 0.430 inch and 0.375 inch diameters. The factory should be contacted for longer sheath lengths.
Milled Groove Tubular Heaters
WATROD milled groove heaters are precision-formed and customized to your hot runner mold application. Even tight radius bends of 0.250 inch maintaining tolerances of ±0.062 to ±0.002 inch are possible. This capability not only allows you freedom to design for the optimum uniform heating pattern for your plastics process, but also guarantees quick and easy installation.
Simply send your groove dimensions in a detailed drawing or on CAD file. Depending on the formation requirements, the resulting CAD design will be transferred to either Watlow's CNC bending equipment or a highly skilled bending operator.
A variety of sheath materials are available including alloy 800, 304 stainless steel and 316 stainless steel, each offering unique advantages of long life in high temperature molds, rigidity to maintain shape during shipment and corrosion resistance.
MULTICOIL™ Heaters
The MULTICOIL heater tubular element with multiple coils and/or thermocouples inside one sheath answers the need for a versatile, innovative tubular multiple coil heater. Watlow's patented method of packaging a thermocouple inside of a heater with one or more resistance coils gives the ability to sense a heater's internal temperature accurately, every time.
Moreover, this is the first tubular heater in the industry with three-phase capability. The three coil, three-phase heater will offer a compact package solution while delivering the full power required in a compact heater package. Previously three separate heaters would have been required to do the same job; therefore Watlow's MULTICOIL heater capabilities save money.
WATROD™ Tubular Heaters
Available in single- or double-ended termination styles, the versatile and economical WATROD tubular heating element from Watlow lends itself to virtually the entire range of immersion and air heating applications.
The single-ended WATROD tubular heater design has both terminals at one end. The opposite end is sealed. Flexible lead wires are 12 in. (305 mm) crimp connected to the terminal pin and have silicone-impregnated fiberglass oversleeves.
The double-ended WATROD, with its round cross-sectional geometry, are highly adaptable for bending—especially when bending is performed in the field. Watlow's double-ended MULTICOIL tubular elements offer various combinations of resistor coils and thermocouples inside one sheath. They have the ability to sense the heater's internal temperature accurately every time, or offer three-phase capability in one element.
Both single- and double-ended WATRODs share many construction features delivering long life—the resistance wire is centered in the heater sheath and electrically insulated with compacted, high-grade magnesium oxide for superior heating performance.
WATROD tubular heating elements have a variety of mounting and termination options making them highly popular among industrial customers.
FINBAR™ Single- Ended Heaters
Composed of aluminized steel fins press-fitted to a one-inch single-ended FIREBAR element, the FINBAR finned tubular heater is designed to improve heat transfer to the air and permits putting more power in tighter spaces—like forced air ducts, dryers, ovens and load bank resistors.
Heat transfer, lower sheath temperature and element life are all maximized by the FINBAR heater's finned construction. Installation is simplified by terminations exiting at one end and mounting accommodations on both ends.