I have a 10an taperd fitting connecting into a fuel filter but, fuel filter does not have that cone tapered surface inside. Do I have to use a straight cut an fitting or if I use an O ring on tapered fitting work? If not mistaking straight cut or tapered an fitting have the samr threads. Is this correct?
I’m not sure I follow what you are asking. All of our fuel filters have tapered male fittings on the inlet and outlet side. Do you have a picture of what you are working with in order to help me understand your setup?