Most spray and rotator heads are designed to work their best at about 30 psi. When pressure is lower, the watering radius will be reduced, so you may need to place your heads closer together to get the coverage you need. Higher pressures – those above about 40 psi – will cause the head to mist or fog.
The optimum operating pressure for most residential sprinkler heads is between 30 and 50 pounds per square inch (PSI). With correct water pressure, each head will perform the way they were designed, and the result will be even spray-patterns and efficient use of water.
A drip system that operates at high pressure (above 40 psi) may appear to be operating adequately, however it is more likely to develop problems over time.
If the gauge reads 40 PSI when the hose is filled with water, we know that the elevation is 92.4 feet. We simply take 40 PSI x 2.31 which equals 92.4. This is not distance, but feet of head.
Drip irrigation systems are designed to work at an even lower pressure than is set for the house, with the optimal pressure for a drip system between 15 and 30 PSI.
Most spray sprinklers have recommended operating pressures between 30 pounds per square inch (psi) and 45 psi. Operating a sprinkler system at a pressure higher than recommended can cause significant water waste, due to excessive flow rates, misting, fogging, overspray, and uneven coverage.
The most common cause of low water pressure in sprinklers is the backflow preventer valves not opening fully. There are two main pipes in your backflow preventer – one horizontal and one vertical. Each pipe has a handle that can be turned to run with the line or across to open the valve.
Maintains constant outlet pressure at 30psi (2.1 bar). Spray nozzles perform best at 30psi.
Adjust the dial and deflector on impact sprinklers manually.
If you have a system with these sprinklers, try manually adjusting the heads to increase pressure. Every brand of sprinkler is different, but there's typically a pressure valve on the top that you can turn manually to increase the pressure.
Divide the farmland or garden into zones
If you notice that the water pressure in your drip irrigation system is low, you can divide the farmland onto zones using valves. With the division of the farmland into zones, few drip laterals will serve each zone; this will increase the water pressure in the drip system.
For spray heads, it is 30 psi, with an operating range of 15 to 30 psi. For drip lines, this is about 20 psi, with an operating range of 15 to 30 psi. Remember, flow rate and pressure are directly related to one another. If pressure is not well-controlled, irrigation efficiency will suffer.
Turn the water flow up or down to affect the spray distance.
This is the easiest way to adjust how far your sprinkler sprays. Twist the knob of your water source to the right to increase the water flow. Turn it to the left to decrease water flow.
Impact sprinklers are excellent for low-pressure water sources. This type of sprinkler is built with integrated regulation valves that control water flow. Using impact sprinklers will still allow you to achieve healthy growth of grass and plants, even if the water pressure in your house is less than ideal.
The screw acts as a water pressure regulator. If you tighten the screw the water pressure will be more and if you loosen the screw the water pressure will be less. Turn the screw clockwise to tighten it and increase the pressure, or turn it counterclockwise to decrease the pressure.
The most commonly used residential sprinklers are 4.9 k-factor pendant sprinklers. The minimum pressure and flow for these sprinklers is 7 psi at 13 gpm for spacing up to 16 feet by 16 feet.
The average usage of water in a residential sprinkler system is between 12 – 30 gallons per minute depending on the type and size of the sprinkler head.
Most residential water pressures are generally in the 40 - 80 PSI range. Under 40 is considered low, so you may need to boost pressure if installing an irrigation system. Over 80 is high, and many household water appliances may be at risk of damage over this range. A pressure reducing valve may be necessary.
You need pressure regulators to achieve the intended distribution pattern and application rate. If you do not control the system pressure, it can negatively affect the sprinkler performance. Without regulators, the throw radius can alter, fitting, and emitters could even take damage or blow out of the tubing.
Summary. When you increase the size of your pipes and fittings, it can increase the water pressure and decreases the velocity, through water flow will be increased. This means that the amount of force that water can exert on a pipe or fitting is decreased.
The relationship between the pressure in the pipe and the flow rate is proportional. That is, the higher the pressure, the higher the flow rate. The flow rate is equal to the velocity multiplied by the cross section. For any section of the pipe, the pressure comes from only one end.
In a water flowing pipeline, water pressure and pipe size are dependent on each other. If the diameter of a pipe decreases, the pressure in the pipe will automatically rise. As per the scientific approach, pressure can be reduced by reducing the area of conveyance.
“If you put your thumb over the end of the hose, the velocity of the water coming out increases. It's the same for the blood in your arteries—blood pressure is the force at which you're pushing the blood through.”
Pressure regulators are generally installed on the outflow side of the valves. It should be placed after the backflow preventer and filter.
Do I need a water pressure regulator? Building code requires that homes that receive water with pressure greater than 80 PSI have a water pressure regulator. A home's water pressure should stay in the range of 40 to 60 PSI.