Due to the consumption of compressed natural gas (CNG) as an alternative fuel in cars and its cost-effectiveness compared to gasoline, there are a large number of dual-fuel vehicles in our country, which create irreparable risks if safety precautions are not followed. In order to prevent these risks, according to the national standards of cars and tanks of dual-fuel vehicles should be inspected. With legal licenses and certificates from Iran’s National Certification Center, we carry out technical inspections of dual-fuel vehicles according to standards 9426-9747, as well as technical inspections of vehicle tanks and monitoring the hydrostatic test process of tanks according to standards 6792-9426.