Only a handful of manufacturers have been approved by UOP and ConocoPhillips for use under their license. End users are obliged to use hf acid valves made by these manufacturers alone, and otherwise risk to loose the licensor's guarantees for the safety of the plant and the integrity of the alkylation process.
Although alkylation valves are made of relatively common steel -- they either come in carbon steel body and monel trim, or monel body and trim -- they also come with a series of safety and performance features that are unique to these valves. For the time being, only gate, globe, check and plug valves are approved for UOP and ConocoPhillips alkylation plants.
Other materials used at alkylation plants often follow NACE norm 5A-171 "Materials for Storing and Handling Commercial Grades of Aqueous Hyrofluoric Acid and Anhydrous Hydrogen Fluoride". This norm os one of the most demanding ones in the process industry.