Watlow FIREBAR Data sheet

Tubular Heaters

Nickel-Chromium

Resistance Wire

Wire to Pin 360˚

Fusion Weld

Metal Sheath

MgO Insulation

Flexible Lead Wires

Nickel-Chromium

Resistance Wire

Wire to Pin 360°

Fusion Weld

Metal Sheath

MgO Insulation

Flexible Lead Wires

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

• Improving heat transfer with a significantly larger

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. Details are contained in the
FINBAR section, starting on page 110.

Double-Ended Performance Capabilities

One Inch

• Watt densities to 120 W/in2(18.6 W/cm2)

• Incoloy®sheath temperatures to 1400°F (760°C)

• 304 stainless steel sheath temperatures to

• Voltages to 240VAC

• Amperages to 48 amperes per heater or 16 amperes

5

⁄8 Inch

• Watt densities to 90 W/in2(13.9 W/cm2)

• Incoloy®sheath temperatures to 1400°F (760°C)

• Voltages to 240VAC

• Amperages to 32 amperes per heater or 16 amperes

to carry heat from the sheath

boundary layer allowing much more liquid to flow up
and across the sheath’s surface

1200°F (650°C)

per coil

per coil

One Inch Double-Ended FIREBAR Element and

5

⁄8 Inch Double-Ended FIREBAR Element and

Lead Configurations

Lead Configurations

Single-Ended Performance Capabilities

One Inch

• Watt densities to 60 W/in2(9.3 W/cm2)

• Incoloy®sheath temperatures to 1400°F (760°C)

• 304 stainless steel sheath temperatures to
1200°F (650°C)

• Voltages to 240VAC

• Amperages to 48 amperes per heater or 16 amperes
per coil

5

⁄8 Inch

• Watt densities to 80 W/in2(12.4 W/cm2)

• Incoloy®sheath temperatures to 1400°F (760°C)

• Voltages to 240VAC

• Amperages to 16 amperes per heater

WATLOW

®

91

Tubular Heaters

FIREBAR Double-Ended Heaters

Specifications

Applications Direct immersion; water, oils, etc. Direct immersion; water, oils, etc.

Clamp-on; hoppers, griddles Clamp-on; hoppers, griddles
Forced air heating (Also see FINBAR, page 110) Forced air heating
Radiant heating Radiant heating

Watt Density Stock: up to 90 (13.9) Stock: up to 90 (13.9)

W/in2(W/cm2) Made-to-Order (M-t-O): up to 120 (18.6) Made-to-Order (M-t-O) up to 90 (13.9)

Surface Area Per Linear In. (cm) 2.3 in2(14.8 cm2) 1.52 in2(9.80 cm2)

Cross Section

Height 1.010 (25.7) 0.650 (16.5)

± 0.015/0.010 in. (0.381/0.254 mm)

Thickness 0.235 (5.9) 0.235 (5.9)

± 0.005/0.001 in. (0.127/0.025 mm)

Sheath Material—Max. Stock: Incoloy

Operating temperature M-t-O: Incoloy

Sheath Length Stock: 15 to 114 (381 to 2896) Stock: 15 to 51 (381 to 1295)

in. (mm) M-t-O: 11 to 180 (280 to 4572) M-t-O: 11 to 115 (280 to 2920)

Straightness Tolerance

Major axis in./ft (cm/m): 0.062 (0.52) 0.062 (0.52)
Minor axis in./ft (cm/m): 0.062 (0.52) 0.062 (0.52)

No-Heat Length (Refer to page 105) 1 in. min., 12 in. max. (25/305 mm) 1 in. min., 12 in. max. (25/305 mm)

Max. Voltage—Amperage 240VAC—48A 240VAC—32A
Max. Hipotential 1480VAC 1480VAC
Max. Current Leakage Per Coil (cold) 3mA 3mA
Max. Amperage Per Coil 16A 16A
Phase(s) 1-ph parallel/series, 3-ph delta/wye 1-ph parallel/series
Resistance Coils 3 or 2 2

Ohms/In./Unita 0.270Ω min.—2.833Ω max. 0.040Ω min.—4.250Ω max.
Ohms/In./Coila 0.080Ω min.—8.500Ω max. per coil 0.080Ω min.—8.500Ω max. per coil

Terminations Flexible lead wires Flexible lead wires

Quick connect (spade) Quick connect (spade)
Screw lug (plate) Screw lug (plate)
Threaded stud Threaded stud

Seals Stock: Lavacone 221°F (105°C) Stock: Lavacone 221°F (105°C)

M-t-O: Ceramic base 2800°F (1535°C) M-t-O: Ceramic base 2800°F (1535°C)

Min. Axis Bending Radius Major: 1 (25) Major:3⁄4 (19)

in. (mm) (Do not field bend) Minor:1⁄2 (13)

Minor:5⁄32 (4) 180° bend Minor:5⁄32 (4) 180° bend

Mounting Options Brackets (Type 1, 2 and 3) Brackets (Type 1, 2 and 3)

Threaded bulkhead or fitting Threaded bulkhead or fitting

Surface Finish Options Bright anneal, passivation Bright anneal, passivation

Agency Recognition UL®Component recognition to 240VAC UL®Component recognition to 240VAC

CSA Component recognition to 240VAC CSA Component recognition to 240VAC

a

Resistance values valid for three coil 1 in. (25 mm) FIREBAR only.

One Inch FIREBAR

®

1400°F (760°C) Stock: Incoloy

®

1400°F (760°C) M-t-O: Incoloy

304 SS 1200°F (650°C) 304 SS 1200°F (650°C)

Silicone rubber 392°F (200°C) Silicone rubber 392°F (200°C)
Lavacone 221°F (105°C) Lavacone 221°F (105°C)
Epoxy resin 266/356°F (130/180°C) Epoxy resin 266/356°F(130/180°C)

090° bend Minor:1⁄2 (13) 090° bend

(File # E52951) (File # E52951)

(File # 31388) (File # 31388)

5

⁄8 Inch FIREBAR

®

1400°F (760°C)

®

1400°F (760°C)

92

WATLOW

®

Tubular Heaters

FIREBAR Single-Ended Heaters

One Inch Single-Ended FIREBAR

5

⁄8 Inch Single-Ended FIREBAR

Specifications (Continued)

Applications Clamp-on; hoppers, griddles Clamp-on; hoppers, griddles

Forced or convection air heating Forced or convection air heating
(Also see FINBAR, page 110)

Watt Density Stock: up to 40 (6.2) Stock: up to 20 (3.1)

W/in2(W/cm2) M-t-O: up to 60 (9.3) M-t-O: up to 60 (12.4)

Surface Area Per Linear In. (cm) 2.3 in2(14.8 cm2) 1.52 in2(9.80 cm2)

Cross Section

Height ± 0.015/0.010 in. (0.381/0.254 mm) 1.010 (25.7) 0.650 (16.5)
Thickness ± 0.005/0.001 in. (0.127/0.025 mm) 0.235 (5.9) 0.235 (5.9)

Sheath Material—Max. Stock: 304 SS 1200°F (650°C) Stock: Incoloy

Operating temperature M-t-O: Incoloy

Sheath Length Stock: 11 to 461⁄4 (280 to 1175) Stock: 111⁄2 to 52 (280 to 1321)

in. (mm) M-t-O: 11 to 120 (280 to 3048) M-t-O: 11 to 116 (280 to 2946)

Straightness Tolerance

Major axis in./foot (cm/m): 0.062 (0.52) 0.062 (0.52)
Minor axis in./foot (cm/m): 0.062 (0.52) 0.062 (0.52)

No-Heat Length (Refer to page 105)

Top Cold End 1 in. min., 12 in. max. (25/305 mm) 1 in. min., 12 in. max. (25/305 mm)
Bottom (blunt end) Cold End 1 ph- 0.5 min., 2 in. max. (13/51 mm) Only available at 1.25 in.

3 ph- 0.75 min., 2 in. max. (19/51 mm) N/A

Max. Voltage—Amperage 240VAC—48A 240VAC—16A
Max. Hipotential 1480VAC 1480VAC
Max. Current Leakage (cold) 3mA 3mA
Max. Amperage Per Coil 16A 16A
Phase(s) 1-ph, 3-ph wye 1-ph
Resistance Coils 3 or 1 1

Ohms/In./Unit 0.200Ω min.—14.00Ω max.
Terminations Flexible lead wires Threaded stud Flexible lead wires

Quick connect (spade) Quick connect (spade)
Screw lug (plate) Screw lug (plate)

Seals Stock: Lavacone 221°F (105°C) Stock: Lavacone 221°F (105°C)

M-t-O: Ceramic base 2800°F (1535°C) M-t-O: Ceramic base 2800°F (1535°C)

Min. Axis Bending Radius Major: 1 (25) Major:3⁄4 (19)

in. (mm) (Do Not Field Bend) Minor:1⁄2 (13)

Minor:5⁄32 (4) 180° bend Minor:5⁄32 (4) 180° bend

Mounting Options Bracket (Type 2) Bracket (Type 2)

Threaded bulkhead Threaded bulkhead

Surface Finish Options Bright anneal Bright anneal

Optional Internal Thermocouple — —

Single-end Configuration Stock: Slotted Stock: Slotted

M-t-O: Slotted, sealed or welded M-t-O: Slotted, sealed or welded

Agency Recognition UL®Component recognition to 240VAC UL®Component recognition to 240VAC

CSA Component recognition to 240VAC CSA Component recognition to 240VAC

®

1400°F (760°C) M-t-O: Incoloy

304 SS 1200°F (650°C) 304 SS 1200°F (650°C)

➀

Silicone rubber 392°F (200°C) Silicone rubber 392°F (200°C)
Lavacone 221°F (105°C) Lavacone 221°F (105°C)
Epoxy resin

(File # E52951) (File # E52951)

(File # 31388) (File # 31388)

266/356°F (130/180°C)

090° bend Minor:1⁄2 (13) 090° bend

0.200Ω min.—14.00Ω max.

®

®

Epoxy resin

1400°F (760°C)
1400°F (760°C)

➀

266/356°F (130/180°C)

➀

Based on 1-phase, single voltage heater.

WATLOW

®

93

Tubular Heaters

FIREBAR Single/Double-Ended Heater

Features and Benefits

One Inch Features and Benefits

Double-Ended

Streamline, 0.235 x 1.010 in. (5.9 x 25.6 mm) normal

to flow dimension

• Reduces drag

70 percent greater surface area per linear inch
compared to a 0.430 in. (11 mm) diameter round
tubular heater

• Reduces watt density or packs more kilowatts in

smaller bundles

Compacted MgO insulation

• Maximizes thermal conductivity and dielectric strength

Nickel-chromium resistance wires

• Precision wound

0.040 in. (1 mm) thick MgO walls

• Transfers heat more efficiently away from the

resistance wire to the sheath and media—conducts
heat out of the element faster

Three resistance coil design

• Configurable to either one- or three-phase power,

readily adapts to a variety of electrical sources and
wattage outputs

Lavacone seals

• Provides protection against humid storage conditions,
moisture retardant to 221°F (105°C)

Single-Ended

Single-ended termination

• Simplifies wiring and installation

Streamline, 0.235 x 1.010 in. (5.9 x 25.6 mm) normal
to flow dimension

• Reduces drag

70 percent greater surface area per linear inch

• Reduces watt density from that of the 0.430 in.
(11 mm) diameter round tubular

Slotted end

• Provides installation ease in clamp-on applications

Lavacone seals

• Provides protection against humid storage conditions,
moisture retardant to 221°F (105°C)

s

5

⁄8 inch Features and Benefits

Double-Ended

Special sheath dimensions, 0.235 x 0.650 in.
(5.9 x 16.5 mm)

• Results in a lower profile heater

10 percent greater surface area per linear inch

• Reduces watt density from that of the 0.430 in.
(11 mm) diameter round tubular heater

0.040 in. (1 mm) thick MgO walls

• Transfers heat efficiently away from the resistance
wire to the heated media—conducts heat out of the
element faster

Lavacone seals

• Provides protection against humid storage conditions,
moisture retardant to 221°F (105°C)

Single-Ended

Single-ended termination

• Simplifies wiring and installation

Special sheath dimensions, 0.235 x 0.650 in.
(5.9 x 16.5 mm)

• Results in a lower profile heater for more wattage in
a smaller package

Slotted end

• Provides installation ease in clamp-on applications

Lavacone seals

• Provides protection against humid storage conditions,
moisture retardant to 221°F (105°C)

94

WATLOW

®

Tubular Heaters

0.430 in.

0.235 in.

FIREBAR Single/Double-Ended Heate

Performance Features

FIREBAR’s flat tubular element geometry produces
performance features and benefits not possible with
traditional round tubular technology. The following
describes how and why the FIREBAR is functionally
superior for many applications—especially those
requiring large wattage with low watt density.

By using the FIREBAR element it will:

• Lower the element’s watt density

• Reduce element size and keep the same watt density

• Increase element life by reducing sheath temperature

Flat Shape Produces Lower Sheath Temperature

The FIREBAR element operates at a lower sheath
temperature than a round tubular element of equal
watt density because of three factors.

1. Flat Surface Geometry

FIREBAR’s flat, vertical geometry is streamline. The
liquid’s flow past the heating element’s surface is not
impaired by back eddies inherent in the round tubular
shape. The FIREBAR’s streamline shape results in fluids
flowing more freely with more heat carried away from
the sheath.

rs

Comparative Widths

Watt Density and Surface Area Advantages

The surface area per linear inch of a 1 in. FIREBAR is
70 percent greater than the 0.430 in. (11 mm) diameter
round tubular element. The5⁄8 in. FIREBAR is nearly
10 percent greater.

2. Normal to the Flow

The element’s width (thickness) of both 1 inch and

5

⁄8 inch FIREBAR elements is just 0.235 in. (5.9 mm).
Compared to a 0.430 in. (11 mm) round tubular
element, this relative thinness further reduces drag
on liquids or gases flowing past the heater.

3. Buoyancy Force

The FIREBAR element’s boundary layer, or vertical side,
is greater than virtually all round tubular elements. This
is 1.010 and 0.650 in. (25.6 and 16.5 mm) for the one
inch and5⁄8 in. FIREBARs respectively, compared to a

0.430 in. (11 mm) diameter on a round tubular
element. The FIREBAR element’s increased height,
relative to flow, increases the buoyancy force in
viscous liquids. This buoyancy force can be as much as
10 times greater depending on the FIREBAR element
and liquid used.

WATLOW

®

Surface Area Per
Linear inch (cm)

Element Type in

1 in. FIREBAR 2.30 in

5

⁄8 in. FIREBAR 1.52 in

0.430 in. Round 1.35 in

2

2

2

2

(cm2)

(5.84 cm2)
(3.86 cm2)
(3.43 cm2)

Flat vs. Round Geometry Comparisons

The unique flat surface geometry of the FIREBAR
element offers more versatility in solving heater problems
than the conventional round tubular element. The
following comparisons show how the FIREBAR element
consistently outperforms round tubular heaters.
FIREBAR elements can:

• Reduce coking and fluid degrading

• Increase heater power within application space
parameters

• Provide superior heat transfer in clamp-on applications
resulting from greater surface area contact

• Lower watt density

Reducing watt density or sheath temperature extends life.
The FIREBAR element allows you to do either, without
sacrificing equipment performance … as is proven by the
accompanying Heater Oil Test, Air Flow and Watt Density
vs. Sheath Temperature graphs.

95

Tubular Heaters

Oil Temperature —°F

Sheath Temperature —°F

700

650

600

550

500

450

400

350

300

150 200 250 300 350 400 450 500

1 Inch FIREBAR Heater

0.430 Inch Round Tubular

350

325

300

275

250

225

200

175

150

75 100 125 150 175 200 225 250

Sheath Temperature —°C

Oil Temperature —°C

40 W/

i

n

2

(

6.2 W/

cm

2

)

30 W

/i

n

2

(4.7 W

/

cm

2

)

40 W/i

n

2

(6.2

W/

cm

2

)

30 W

/i

n

2

(

4.7 W/cm

2

)

FIREBAR Single/Double-Ended Heater

Technical Data

The FIREBAR Heater Oil Test graph compares sheath
temperatures of 40 W/in2(6.7 W/cm2) flat and round
tubular elements. The FIREBAR element consistently
operates at a lower sheath temperature than the round
tubular element, even when light oils are tested at
different temperatures. This reduces the chance that
coking and fluid degradation will occur.

In fact, the FIREBAR element’s sheath temperature
at 40 W/in2(6.7 W/cm2) is lower than a 30 W/in
(4.6 W/cm2) round tubular element.

2

s

FIREBAR Heater Oil Test

Heater Size and Power

The Heater Size Comparison chart shows, at the same
wattage and watt density, the FIREBAR element is
38 percent shorter than a 0.430 in. (11 mm) round
tubular element. The FIREBAR element requires less
space in application and equipment designs.

The Heater Power Comparison chart demonstrates equal
watt density, element length and increased total wattage
for the FIREBAR element. The power in the FIREBAR
element is 70 percent greater.

96

Heater Size Comparison

Heated Length

Element in. (mm) Wattage W/in2(W/cm2)

1 in. FIREBAR Element 197⁄8 (504.8) 1000 23 (3.6)

0.430 in. Round
Tubular Element 321⁄4 (819.0) 1000 23 (3.6)

Heater Power Comparison

Heated Length

Element in. (mm) Wattage W/in2(W/cm2)

1 in. FIREBAR Element 321⁄4 (819.0) 1700 23 (3.6)

0.430 in. Round
Tubular Element 321⁄4 (819.0) 1000 23 (3.6)

WATLOW

®