Presents review for guidance of present day operators of anhydrous hydrogen fluoride alkylation process. Covers early laboratory and pilot plant tests and metallurgical problems encountered in first commercial units. Steel was recognized early as a material for construction of principal components of process units but was not satisfactory for all services. Morel, ruled out initially, later was found satisfactory for service as trim and in various kinds of valves. Valves with steel corks failed when the H.F attacked then, often sealing then into inoperable condition. Grease used for lubrication was troublesome in the stream.
Numerous kinds of packing were tried, but none were entirely satisfactory at first. Monel and fluorocarbons made available later solved packing and valve seat problems and also problem of protecting glass sight level gauges.
Steel bolts failed rapidly from stress corrosion cracking when small leaks resulted in acid attack. K. Monel bolts also failed. Duranickel bolts were satisfactory.
Dangers of contamination of process stream by water or water by acid are cited. Constant pH checks are advocated as a control measure. External corrosion is small when good housekeeping is maintained.
