Ptfe pipe 1) makes from pure ptfe 2) it has an expanded network composed of superfine fivers and joints 3) the combination of flexbility high longitudinal strength and easy deformability in the transverse direction makes expanded ptfe unsintered tape very suitable for packing and threadsealing applications. 4) it is not be suitable for use in certain critical application, for example when contact with high concentration of gaseous oxygen or liqud oxygen involved.