Watlow Heater Catalog

Tubular Heaters

FIREBAR Single/Double-Ended Heaters Technical Data (Continued) Clamp-On Applications Direct immersion in the liquid may not always be

FIREBAR elements are also economical platen heaters. The Platen Heating graph shows FIREBAR’s large, flat surface area allowing it to operate at twice the watt density of round tubular elements … without sacrificing heater life. Clamps should be placed approximately 6 in. (150 mm) apart and torqued down with 60 in.-lbs (6.8 Newton meters).

practical. In these instances the FIREBAR element can be clamped to a tank wall. Heat from the FIREBAR is conducted to the tank wall and into the media.

Platen Heating (˚C)

Platen Heating (˚F)

Allowable Watt Densities of FIREBARs in Clamp-on-Application

Allowable Watt Densities of FIREBARs in Clamp-on-Application

45

7

Subtract 20% of Indicated Watt Density for 2 Element FIREBAR

40

Subtract 20% of Indicated Watt Density for 2 Element FIREBAR

6

1000°F

35

5 Watt Density—W/cm 2 4 3

500°C

30 Watt Density—W/in 2 200°F 25 20 15 10

Sheath Temperature

Sheath Temperature

800°F

400°C

600°F

300°C

400°F

2

200°C

100°C

1

5

200

400

600

800

1000

600

100

200

300

400

500

Platen Temperature—°F

Platen Temperature—°C

Watt Density vs. Sheath Temperature The Watt Density vs. Sheath Temperature graph features sheath temperature curves for commonly heated substances. A FIREBAR element’s watt density will result in the sheath temperature shown at the intersecting point of its vertical watt density line and substance curve.

Watt Density vs. Sheath Temperature

4 Watt Density—W/cm 2 5 6

1

2

3

9

7

8

1000

1800

900

1600

Air

800

1400

700

1200

600

1000

500

800

400

SAE 30 Cooking Oil

600

300

Sheath Temperature—°F

Sheath Temperature—°C

400

200

Water

200

100

0

0

10

20

30

40

50

60

Watt Density—W/in 2

90