Methods for performing flow reactions utilizing high temperature hydrofluoric acid

A method of performing a reaction is disclosed comprising flowing a reaction mixture (50) comprising HF past a compression seal (40) within a flow reactor (20), wherein the compression seal (40) includes an O-ring or gasket (30, 32) and where the O-ring or gasket (30, 32) comprises fluoroelastomer (to include fluoroelastomers and perfluoroelastomers), while maintaining the reaction mixture comprising HF at a temperature of 50° C. or greater [generally at a temperature in the range of from 50° C. and greater (60, 70, 80, 90, 100, 120, 150, and 180° C.) up to 220° C.], using O-rings or gaskets (30, 32) that comprise a fluoroelastomer having a pre-use tensile strength in the range of from 0.1 to 14 MPa measured according to IS037, and desirably further having a compressive set in the range of from 0 to 12% measured according to IS0815.