... Safe using and reliablity, is the preferred electrical heating pipe for manufacturer of various electric appliances.5)Heating pipes are ... materials: magnesium oxidetube Material: Stainless steel seamless pipe, welded pipe, copper, yellow brass pipe, carbon steel pipeCommon diameter:Φ22,Φ20,Φ18,Φ16 ... usersQuality certification : UL TUVquality gurantee TUV / UL certification spiral heating pipe