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!