The amount of pressure exerted at a valve is _____ PSI if water is 35 feet above the source.

To determine the pressure exerted at a valve when water is 35 feet above the source, it's essential to understand how water pressure is generated by elevation. The pressure in a water column is typically measured in pounds per square inch (PSI), and can be calculated using the formula that relates feet of head to pressure: 1 foot of water produces approximately 0.433 PSI.

Calculating the pressure from 35 feet involves multiplying the height (35 feet) by the pressure per foot (0.433 PSI):

35 feet x 0.433 PSI/foot = approximately 15.155 PSI.

When rounded, this value is 15 PSI. Thus, when you have water elevated 35 feet above where it is exerting pressure, the pressure at the valve would be about 15 PSI. This aligns with industry knowledge that pressure increases with the height of the water column due to gravity.

This understanding of how hydraulic pressure works is crucial for contractors to ensure proper water flow and system performance in various landscaping and irrigation applications.