In a piping system connected to the outlet of an crude oil tank, process man has located the expansion joint after the valve which is connected to tank's nozzle. Since this expansion joint is located after the valve, it must be able to withstand the design pressure of the piping system. However, if this expansion valve were located before the valve, and was connected to the tank's nozzle, it should have only withstand the pressure due to fluid height in the tank, which is one-twentieth of the piping design pressure. I was wondering whether it is practical to connect the expansion joint directly to the tank's nozzle. I appreciate it if could share your similar experience.