... metal tube into the heating wire, and the gap part of the tightly filled in crystallization of magnesium oxide ... Safe using and reliablity, is the preferred electrical heating pipe for manufacturer of various electric appliances.5)Heating pipes ... materials: magnesium oxidetube Material: Stainless steel seamless pipe, welded pipe, copper, yellow brass pipe, carbon steel pipeCommon diameter:Φ22,Φ20,Φ18,Φ ...