One exemplary embodiment can be a process for treating an interior of equipment for an isomerization unit. Generally, the isomerization unit includes at least one of a drying zone, an isomerization reaction zone, and a stabilizer zone, for receiving a feed stream. Usually, the feed stream includes one or more C4-C8 hydrocarbons. The process can include combining an anhydrous hydrogen stream and anhydrous organic chloride stream to form a hydrogen chloride feedstock, and passing the hydrogen chloride feedstock to a reaction zone containing a catalyst including at least one of nickel, palladium, and platinum on an alumina support to form a hydrogen chloride stream, and passing the hydrogen chloride stream upstream of the isomerization reaction zone.