Dura Cooperation has a Dura manifold that is designed with O-Rings that allows you to hand tighten them on to the valve without any leakage or teflon tape. If by chance you have used a tool that has tighten down to tight it has a chance to compromise the features of the manifold system. As Shown in this Picture:
There is a valve manufactured by Irritrol called the 2400 series. (This is a 1" size valve ) If this valve is installed in reverse it will act as a normally open valve. Have A Great Day!