The gate valve on the right is the fuel shutoff valve from the tank. The tank does not have a pickup tube, fuel goes directly from the bottom of the tank to your fuel manifold. The valve on the left is for sampling fuel from the tank or draining sediment from the low point of the tank. There is a screw cap on the bottom. Remove the cap, loosen the stem and pull the stem up, fuel will drain from the low point of the tank.