A backflow resistant stop valve for an aircraft galley plumbing system comprises a valve body defining an inlet, and inlet chamber, a transfer chamber, an outlet chamber, and an exit. The valve incorporates an anti-backflow device at the exit to prevent backflow, and flow through the body is controlled by a pivoting paddle disposed within the valve body having an upper flap, a spindle, and a lower flap, where the upper flap seals against the inlet chamber and the lower flap seals against the outlet chamber when the paddle is rotated to a first position. The valve utilizes a negative pressure at the outlet chamber that biases the valve closed until a sufficient column of water overcomes the bias.