To test your home's water pressure, you'll only need a simple, low-cost pressure gauge, which you can get at any hardware or home improvement store. Look for one that has female hose threads for a simple connection, a rubber gasket for a tight seal, and the power to measure up to 300 pounds per square inch.
Water pressure is measured in psi, or pounds per square inch, and represents the force at which water enters your home from the water main. Normal psi for a home pipe system is between 30 and 80 psi. While you don't want the psi to be too low, it violates code to be above 80.
Residential water pressure tends to range between 45 and 80 psi (pounds per square inch). Anything below 40 psi is considered low and anything below 30 psi is considered too low; the minimum pressure required by most codes is 20 psi. Pressures above 80 psi are too high.
For example, since water weighs approximately 62.4 pounds per cubic foot, the pressure exerted by 1 foot of water is 62.4 / 144 =. 433 pounds per square inch. Ten feet of water would exert a pressure of 10 X . 433 4.33 pounds per square inch.
If the gauge reads 40 PSI when the hose is filled with water, we know that the elevation is 92.4 feet.
If it's above 80 psi, you probably need to lower your water pressure. There are several less scientific ways to see if you have high water pressure as well. You might have high water pressure if you notice: Expensive Water Bills: If your water bills seem a lot higher than expected, you're using more water than usual.
Water has the unfortunate quality of being heavier than air. In fact, it weighs 62.4 pounds per cubic foot. This mass requires a pressure of 0.433 psi to lift water one foot (62.4 lbs/144 in in ft). To put it another way, one psi will lift water 2.31 feet (1/0.433).
One foot of water equals 0.433 psi. It would take a column of water 2.31 feet to create one pound of pressure.
As water is heavier than air, water pressure rises quicker than air pressure. Water pressure also includes the air pressure portion from the weight of the air above.
Air escapes from a leak faster than water does.
You will see a much faster pressure drop when air escapes from a leak than when water does. If you're trying to get air to a leak to be able to start pinpointing the leak with a listening device, watch for a dramatic drop in pressure.
Water and air pressure gauges are not the same. While both types of gauges measure pressure, they are designed to measure pressure in different mediums and have different measurement scales and ranges.
One inch of water column is equal to a pressure of approximately 1/28 pound per square inch (psi). Stating this another way, a column water 28-inches high produces pressure that is equal to 1 psi.
Let's do a simple one for a very shallow dive. You're heading down 30 feet in saltwater. P = 13.31 psi.
x 0.433 psi per ft. of column or 43.3 psi pressure at ground level. This is also expressed as 100 "feet of head." To fill the water tank, a pump must develop 43.3 psi or 100 ft. of head to lift water to the top of the water tank.
50 psi x 144 square inches/square feet / 62.4 pounds/cubic feet yields 115 feet of water height. So you'd need a barrel of water 115 feet high to create 50 psi of water pressure.
As the name says it is "pounds of force per square inch", if you have a piston of the area of 1 square inch, with a pressure of one PSI a force of 1 pound will be exerted on the piston.
Many toilets really do leak only at night; that's because people use much less water during these hours and in many municipal water systems, the water pressure rises considerably during this time.
For most houses, 80 psi (pounds per square inch) is about right. If the water pressure is over 100 psi, that's too much. This increase in pressure is usually the fault of the municipal water company, which sets the pressure higher in order to accommodate fire hydrants and tall commercial buildings.
Allison Strube, director of water utility for San Angelo, Texas, explained if the pressure in the system drops below 20 PSI, the system becomes vulnerable for bacteria from groundwater or dirt to seep into the pipe and affect the water supply.