Watlow Heater Catalog

Cartridge/Insertion Heaters FIREROD Cartridge Heaters Applications and Technical Data Dimensional Data This table shows minimum/maximum sheath lengths for available FIREROD diameters.

Camber Camber is defined as the maximum deviation of the heater’s center line from straight. FIREROD camber within allowable tolerances is verified via passage through a cylindrical gauge of specified length and diameter. Normally, slight camber does not present a problem since the heater will flex enough to fit into a straight, close-fit hole.

FIREROD Diameter

Length

Nominal in.

Actual

Min. in. (mm)

Max. in. (mm)

in.

(mm)

1 / 8 1 / 4 3 / 8 1 / 2 5 / 8 3 / 4

7 / 8 7 / 8 7 / 8 7 / 8 1 1 ⁄ 1 1 ⁄

0.122 0.246 0.371

(3.1) (6.3) (9.4)

(22.2) (22.2) (22.2) (22.2) (25.0) (25.0)

12 36

(305) (915)

Camber Measurement

48 (1220) 60 (1520) 72 (1830) 72 (1830) 72 (1830)

0.496 (12.6) 0.621 (15.8) 0.746 (18.9) 0.996 (25.3)

4

Camber Ca ber

4

1 1 / 4 (32.0)

1

Indicates recommended maximum sheath length; however, longer lengths may be available.

Allowable Camber Versus Length 0.000 0.020 0.040 0.060 0.080 0.100 0.120 0.140 0.160 0.180 0.200 0 5 10 15 20 25 Max. Allowable Camber (in.)

30

35

40

Heater Length (in.)

Max. camber = 0.020 in. x (length in feet) 2 or 0.005 in., whichever is greater.

11