Pentane-Hexane Cut Isomerization Unit is designed to convert normal paraffines in straight-run gasoline cut into their isomers which have higher octane numbers. Target product of the unit is isomerizate, used as a high octane component for motor gasoline. Incorporation of Isomerization Unit into the plant network allowed solving such significant issues as: - adjustment of benzene/aromatic hydrocarbons content in commercial motor gasoline; - increase of commercial motor gasoline production with high octane number in acc. with requirements of Technical Regulation on "Requirements to motor and aviation gasoline, diesel and marine fuels, fuel for jet engines and furnace fuel oil" approved by RF Government Decree No. 118 on 27.02.2008 (in latest revision). Capital construction project "Pentane-Hexane Cut Isomerization Unit" was executed by company JSC "Salavatneftekhimremstroy" from April, 2011 based on the license and basic design of French company Axens. Project documentation was developed by design institute CJSC "PMP" (General Designer) during less than 1 year. Specialists of CJSC "PMP" Rostov Branch Office were also involved in the execution of design works, as well as LLC "Design Institute SGNKHP" (subcontractor as per client's request) who was responsible for development of PSTS (Environment Protection, Engineering and Technical Measures of Civil Defense and Prevention of Emergency Situations, Fire Safety Declaration), project documentation for control room with transformer substation and intermediate tank farm. Glavgosexpertize approval and construction permit were obtained in September, 2013, and development of detail design documentation was began immediately. In the course of work it turned out that fire-fighting system was required. CJSC "PMP" designed fire-fighting pump station with three fire tanks. This system is used not only for the Isomerisation Unit, but for the needs of the whole plant. Overall water storage capacity is 6000 m3 which can ensure normative time for extinguishing 2 fires (3 hours) with pump station rate 1742,4 m3/h. During project execution CJSC "PMP" developed informational 3D Model of Pentane-Hexane Cut Isomerization Unit which contained all design disciplines and 100% attributes. This model was used by the Client during the whole project and for construction and installation works, which began from October, 2013. General Contractor on construction was LLC "ZSMiK". Individual testing procedures began in May, 2016 and after receiving the feed in November, 2015 comprehensive testing was started. One of the final project stages was loading of platinum catalyst into reactors R-201, R-202 and execution of operational testing under increased capacity up to 110%. On March, 5th 2017 all performance guarantees acc. to product specification and volume were accomplished.