Petro-Tape is made of a virgin polytetrafluoroethylene (PTFE). This rugged, inert and highly resistant tape is impervious to steam, salt water, air, refrigerants, fuels, acids and alkalis, solvents and gases. Its characteristics make it far superior to other PTFE tapes for heavy-duty use. Use on threaded pipe connections, valve stems, hydraulic pressure lines, etc.