Millrose 70661 Monster Roll PTFE Thread Seal Tape, 1/2-Inch x 520-Inch, Blue Has been used to seal fittings carrying water and oil at pressures up to 10,000 PSI -450 Degree to +500 Degree (-268 Degree to +260 Degree) PTFE is completely stable up to +500o F or +260 Degree Use 3/4" (19mm) wide tape for fittings up to 2" (51mm) in diameter Use 1" (25mm) wide tape for fittings larger than 2" (51mm) in diameter Do not use Mill-Rose Blue Monster Thread Sealing Tape on oxygen lines