Sterling Seal and Supply (STCC)  1500.37550 1500/Teadit 24B White PTFE Joint Sealant for Applications in Steel, Glass Lined, PVC and Fiber Glass Pipe Flanges, Fume Ducts, Concrete Lids, Heat Exchangers, 3/8" Wide, 50' Sterling Seal 1500/SSS 24B PTFE Joint Sealant is highly compressive; only light flange bolt pressure is required to effect a seal, particularly useful in plastic, glass and ceramic vessels and pipe Compatible with most chemicals, solvents and petroleum products (except molten alkali metals and elemental fluorine) It's perfectly suited for cryogenic applications 0-14 pH range and will not contaminate flow media; Temperature -450/ + 500 F It comes in the form of a continuous cord with PSA (pressure sensitive adhesive) to aid installation