... . Twist and turn resistance wire in axial direction,that is,the single resistance wire is bended to U shape ... of electrothermal heater tube is called bending resistance wire heater tube.This tube,because fall of screening ... 500 C and 800 C,because of steady,single even solid fusant form,It has good normal ... of surface is too large,big diameter of wire should be chosen.Currently because of limitation of ...