Since 1856, A.Y. McDonald Mfg. Co. has been providing the solution to make water work for you and your community. The curb stop itself plays a pivotal role in the process. By trusting in our many years of experience and talented team of experts, you know you can rely on our Straight Ball Valve Style Flare, FNPT (Female National Pipe Thread), Compression x MNPT (Male National Pipe Thread) Curb Stops.