There is no way to tell. It depends on the orifice of the valve and/or atttached unit, the length of the discharge hose/pipe, the characteristics of the pipe feeding the tee, and the dynamic volume available. Depending on the answers to these questions, the dynamic pressure could be zero with a good flow, zero with poor flow, or some pressure between zero and 60 with a proportional flow rate.: I need a water pressure question answered. If I have one outlet with 2 valves on a tee on a main water line with pressure of : 60lbs in the line what will the water pressure be at the end of each outlet source with : a. one valve open and : b. 2 valves open