[ReelMagic]

Are both pictures from the same tank??? If it is you should have a fuel selection panel somewhere. On my 38 Open its located in the engine room. It allows you to select which tank (port or starboard) fuel is taken for each engine. Remember diesels have return fuel lines as well as supply lines. Also there is a supply fuel line going to the generator. On my 38 Open the generator gets its fuel from the starboard tank and cannot be switched to the port tank. The pictures you posted are the valves located near the tank I believe and can be shut off should maintenance be required on the fuel line itself.. Just guessing.. M2C