Water Pressure Explained

When we turn on the kitchen faucet or start a bath, how the water is coming out may not be something we think about. (Unless of course it is just dripping or not coming out at all!) But, water pressure is something that we should all be familiar with. Water pressure is a measure of the force in which water flows through our pipes. We need this pressure to push the water through the pipes and into our homes, businesses and industries.. Many appliances will not work if the pressure is low, for example a fire hydrant cannot extinguish water if the pressure is minimal or down to a trickle at 10psi.

Water Tower

Most households receive water from a municipal water system. In this method, the water is usually extracted from various groundwater sources and then treated to remove impurities. It is then pumped to water towers, and then gravity takes over to provide the pressure that forces the water through pipes, and eventually to our homes. A similar process will take place in closed systems, as well as in lakes and reservoirs. Water pressure may vary for homes with city water due to old infrastructure issues with the city system or being located a long distance from the main water line. Homes with conventional private wells will often experience inadequate or lower water pressure as well.

The pressure of water may also vary according to their elevation to the water source, as well as with the system that is delivering the water in. A plumbing company website says, "A cubic foot of water weighs 62.4 lb. and exerts .4333 lbs of pressure per square inch on the bottom of its container at a depth of one foot. Therefore, the discharge pressure of a water storage tower 100 ft. tall will be 43.33 psi. If your house is in a valley 50 ft. below the bottom of the tower, the theoretical water pressure at your house will be approximately 65 psi, reduced by the friction in the pipes." Water pressure can vary at different times of the day. Pressure is normally higher later at night when there is less of a water demand, and lower in the morning when more water is being shared by many. No matter what the cause, fluctuating water pressure and flow can disrupt the way your home works.

Typical residential water systems are designed to function under a pressure of 40-70 psi. If the water pressure exceeds 100 psi, a pressure regulator may need to be installed in the line to reduce the pressure to an acceptable range. This protects the equipment in your home from damage caused by excess force exerted by the water. The opposite can occur too; if pressure is below 40 psi, a pressure-booster could be needed to bring it up to acceptable levels. Also, hard water can reduce pressure. High water pressure is also known to waste a lot more water and can rupture pipes, damage fixtures, and injure the people using them. Any wasted water is not good when you consider that many municipalities today not only charge homeowners and businesses high rates for water consumption, but also charge consumers equally high rates for the disposal of wastewater.

It is also important to note that water flow is not the same thing as water pressure. Water flow is the result of your water pressure on the amount of water available for delivery (volume). It is the measure of how much volume passes a specific point per second. Water pressure is the measure of the force of gravity being exerted on the mass of the water. Thus, it depends on the height above the reference and the density of the water. To keep it simple water flow is how much water is flowing off the waterfall and water pressure is how hard the water falls down the waterfall. Low water flow could be a result of an obstruction on the water line, and old pipe with contain mineral build-up or corrosion that reduces the pipe's internal diameter. So, if a water pressure gauge is reading at an acceptable level but the pressure seems off, it may be a flow problem.

If you are unsure of the water pressure at your home, there are a few easy ways to test it. Home Depot carries water pressure gauges and we also carry them here. However, most tanks will already have this feature. Also, a constant pressure valve can easily be installed. This gadget will automatically set flow with the set pressure level for the system. A variable speed pump can also be installed, as well as additional pressure tank capacity-- this will require a professional plumber. With all that said, there is really nothing to stress about. If your water pressure is too high or too low there is always a solution out there that you can easily fix yourself or with the help of a good plumber!

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