A network address translation router for connecting an inside network to an outside network. A coupling mechanism firmly couples the needle and the diaphragm for backward movement of the needle in the direction of the retracted position, a return force generated by the diaphragm for moving the needle back in the direction of the retracted position being introduced into the needle shaft. A fluid flow path extends between the fluid inlet and the fluid outlet and is configured to communicate fluids from the fluid inlet to the fluid outlet.