 |
The most versatile of all electric heating elements, the tubular heater is capable of being formed into virtually any configuration. The range of ratings, sizes, materials and terminations available makes the tubular heater adaptable to many industrial, commercial and scientific applications. The basic construction consists of a helical coi of nickel-chromium resistance wire precisely centered in a metal sheath. This coil is surrounded by magnesium oxide powder which is vibration loaded to insure even density throughout the length of the heater. This entire assembly is then reduced to the finished diameter, compacting the MgO and "freezing" the coil in the center of the heater. |
 |
| MIMIMUM UNHEATED SECTION ON EACH END: |
| 1-1/4" |
11-1/2" to 50" |
| 1-1/2" |
51" to 80" |
| 1-5/8" |
81" to 110" |
| 1-3/4" |
111" to 140" |
| 2" |
141" to 170" |
| 2-1/4" |
171" to 192" |
| 2-1/2" |
193" and Longer |
* 1½" minimum unheated on .430/.137 and .475/.490
|
| TUBULAR HEATER TOLERANCES |
| DIAMETER |
±.005* |
| WATTAGE |
+5%
-10% |
| RESISTANCE |
+10%
-5% |
| SHEATH LENGTH |
±½% |
| EFFECTIVE HEATED LENGTH |
±1% |
|
| PHYSICAL LIMITATIONS AND ELECTRICAL CHARACTERISTICS |
| Sheath Diameter ±.005* |
.250 |
.312 |
.375 |
.430/.437 |
.475/.490 |
| Minimum sheath Length |
11-½ |
11-½ |
11-½ |
11-½ |
11-½ |
| Maximum Sheath Length |
144 |
240 |
240 |
312 |
312 |
| Maximum Voltage |
250 |
250 |
480 |
480 |
480 |
| Maximum Amps |
15 |
30 |
30 |
40 |
40 |
| PIN Diameter |
.093 |
.125 |
.125 |
.187 |
.187 |
| Thread Size |
8-32/10-32 |
8-32/10-32 |
8-32/10-32 |
10-32 |
10-32 |
|
WELDED |
THREADED PIN |
|
Sheath
Material |
Max. Sheath
Temperature °F |
Max. Watts
Per. Sq. In. |
| Copper |
350 |
55 |
| Steel |
750 |
22 |
| Stainless Steel |
1200 |
30 |
| Incoloy |
1500 |
40 |
| * Other Sheath materials available for specific application considerations. Consult factory. |
|
