NK - Natural Kynar Temperature Range -80 °F to 226 °F. Pressure 260 psi at 70 °F. NK material can be autoclaved to 285 °F (140 °C) and meets USP Class VI requirements. Generally, chemically resistant to: most acids, salts, weak bases, halogenated solvents, alcohols, nuclear and UV radiation, oxidants, ozone and deionized water.