Sprinkler System Backflow Basics

August 01, 2022

Sprinkler System Backflow Basics

sprinkler system backflow

Sprinkler System Backflow Basics

Sprinkler System Backflow is used to describe the situation where water reverses or flows back through the meter, causing water to flow in the opposite direction (backward) through your sprinkler system Backflow.

Sprinkler system Backflow occurs when water pressure in your distribution system is much higher than in your municipal water supply system.

Most sprinkler systems have an underground backflow prevention device (usually located near the front of your home) that is an extra safeguard to prevent contaminated water from entering your drinking water supply.

Causes of Sprinkler System Backflow include:

  • Clogged filter screen on a drip controller.
  • Loose fittings of pipes
  • Improper hose connections near the sprinkler head.
  • Installation Errors
  • Damaged or worn-out O-ring on the system or diaphragm.

Some of the Basics Terms used in Sprinkler System Backflow include:

1. Backflow Preventer

Sprinkler system backflow preventer is a term used to describe a device that, upon detecting the presence of a contaminant, prevents it from flowing in the opposite direction (backward) through your sprinkler system.

Sprinkler system backflow Prevention ensures that water flows only in one direction in a piping system. Backflow prevention is typically required by local code enforcement for any pipe carrying potable water from your home or business to any outside spigot or irrigation system. Most codes also require backflow prevention on lines carrying potable water to sewage systems.

The backflow switch or valve turns on and off the Sprinkler system backflow. If it is switched on, water flows in the direction you want it to flow in.

A backflow preventer is designed to be installed upstream from a sprinkler head. A backflow preventer typically consists of a check valve that activates when the sprinkler system is not operating. It will stop the flow if there is something wrong with your water supply, such as a pipe leaking or if there is a blocked toilet.

The Main Principles of backflow Prevention Measures are:

  • Install backflow preventers at the end of sprinkler lines (backflow valves) which can handle any flow rate up to 1 GPM. If the flow is above 1 GPM, use bypass devices.
  • Make sure the devices operate freely; check by closing and opening the valve multiple times and visually inspect for any sticking or binding.
  • Check for leaks on all sides of the devices, the quick connect connections, and any external piping joints.
  • Check and ensure no debris on device parts, including lines and valves.

Types of Sprinkler System Backflow Preventers:

Pressure-Activated Check Valve

This type of Sprinkler system backflow preventer is installed in the water line. When the water pressure drops, the check valve opens and closes when the water pressure increases again.

Pressure Vacuum Breaker

This is a type of Sprinkler system backflow preventer that uses a vacuum to activate the device. It acts as a check valve but is designed to blow out of the way when there is an overflow (overpressure) and is usually installed in the water pipe.

Air Gap Backflow Preventer

This type of Sprinkler system backflow preventer uses air to activate the device. It acts as a check valve but is designed to open when running an appliance that draws water through the pipe.

Double Check Valve

This type of Sprinkler system backflow preventer uses both an air gap and pressure-activated mechanism. It usually opens when there is not enough pressure to activate the air gap, but it closes if the water pressure drops.

Anti-Siphon backflow preventer

This type of Sprinkler system backflow preventer is installed on the end of the pipe. The Anti-Siphon prevents siphoning by using a check valve with a valve stem to ground the fittings. It is usually used in valves for fire sprinklers, typically metal with rubber seals, and cannot be easily bypassed.

2. Sprinkler Valve Box

Sprinkler Valve describes the box where the sprinklers are connected to their control valves or controller.

Sprinkler Valve Boxes are typically constructed of plastic or metal and have a lid. The lid is usually hinged and can be locked from inside the box. The cover has several markings, including valve numbers, spray pattern numbers, and valve settings. The lid also has an “invert” marking that is sometimes used to indicate a valve that needs to be turned on in the case of a fire.

A sprinkler box is usually installed inside a wall next to your house. This box is typically behind the front door and can be accessed by unplugging the utilities. It has various settings such as water pressure, irrigation interval, sprinkler pattern, and on/off valve settings for each of the sprinklers within one zone.

3. Manifold

A manifold is a tube with a spot, which may also be referred to as a water line or pipe. The spot has an outlet pipe through which the water or sprinklers pass to the sprinkler heads. The outlet pipe does not go inside the house but rather to the point of entry of the sprinklers. The manifold is typically cast iron or plastic and can be installed on any outside spigot or irrigation valve.

The most common type of manifold connector is male threads and is used for quick disconnects at the sprinkler head. Other manifolds are available, such as quick connectors, threaded female, and threaded male. These are all designed for connecting up to different types of pipes or valves and can vary according to your needs and your house plumbing layout.

4. Pump Control Valve

A pump control valve is a valve used to change the water flow from a sprinkler system. They are commonly found in most irrigation systems and operate by applying pressure to one side of the valve, which turns on the flow. The pressure also closes off the discharge port when you want to turn off the water supply.

The pump control valve is installed on the sprinkler line. The pressure is usually supplied at the bottom of the sprinkler valves by pulling a rubber handle between your thumb and forefinger, which opens up the valve. Some sprinkler valves have grips around their outside edges that may be used to open up the valve.

5. Master Valve

The master valve is an electric valve that controls the main water supply, which goes to all the sprinkler valves. The master valve is installed upstream from the zone valves, which control water flow to each zone. The master valve has a small pump, which turns on and off depending on the signal received.

Master Valve helps reduce water loss in case of a leaky station valve. They also are used to turn off all the drives on the irrigation system at once.

The master valve can be connected to a computer to operate automatically per programmed settings such as switch on/off time, watering hours, and soil sensing. The computer can also operate the valves at different times of day, depending on the needs of your lawn or other plant life in your yard.

6. Electric Solenoid valves

These are used for quick-disconnecting valves and are connected to the irrigation system. They often have a pressure relief valve on the side of the solenoid valve, which will let out pressure if there is a pressure loss.

Electric Solenoid Valves usually operate at low voltage, normally 24 volts (V) AC. These valves are activated by either pushing a button or pulling on a handle. They are typically used on sprinklers or irrigation valves but can also be found on the residential side of the plumbing system.

7. Lawn Nozzles

On the residential side of the plumbing system, there can be various types of sprinkler heads designed for different things. There are straight lines, curved lines, and many more. The nozzles can open up any combination of sprinklers to suit your needs and the suitability of your lawn or outdoor space.

The nozzles have a flow pattern that can be adjusted by rotating them in one direction or moving them back and forth. The water pressure supplied to each nozzle is controlled by a different pressure control device on each nozzle. The flow pattern can vary depending on what you need.

The nozzles have different types of fittings or nozzles. They vary from ABS plastic, aluminum, brass, and even PVC. The nozzles are typically connected to the sprinkler valve via a quick connect fitting screwed onto the valve. The nozzle valves are usually topped with a rubber gasket to seal them against any dirt getting into the sump from the backflow prevention devices in the system.

There are various types of Sprinkler Heads used in the residential plumbing system. These include:

Fixed spray head

These are umbrella-shaped sprinkler heads with a straight line pattern. Depending on the design, there may be either one or two nozzles. The spray pattern can vary from a single arc to a complete 120-degree broad way of coverage.

Rotating spray head

Rotating spray heads are very similar in construction to the fixed spray head. They use the same sprinkler connection type and have one or two nozzles. The nozzle will cover a specific pattern depending on the position of the head. Some of these sprinkler heads rotate 360 degrees, so if you have a rectangular space to cover, one of these would be a good option.

Drip nozzle

These are pretty similar to the sprinkler heads used for fixed lines. The only difference is the rotational pattern of this type of sprinkler head. Wax rings are used in place of sprays and allow a good, even distribution of water to be delivered to the grass. This reduces soil compaction and erosion and gives your lawn better health.

Backflow for Sprinkler

Backflow for sprinkler can be defined as a plumbing system used in many commercial and residential structures to provide water supply to irrigation systems, firefighting systems, and other auxiliary devices or equipment. Backflow for sprinkler preventers is essential as they prevent the main water supply from being contaminated by impure liquid flow back into the supply.

The concept of backflow for sprinkler is quite simple. The main pressurized water supply enters the system through pipes, valves, or fittings and then gets dispersed to different parts of the system through more conventional valves.

Backflow for sprinkler devices contains the volume of water in a system, prevents water supply contamination, and controls water flow. This helps to minimize wastage and the use of precious resources.

Backflow for sprinkler devices is necessary as they prevent water supplies from becoming contaminated. Some examples of contamination include the following:

Backflow for sprinkler devices is also used to provide water for firefighting, irrigation, and other purposes. These require high-pressure conditions, which can be higher than usual household pressure. Backflow for sprinkler devices is necessary to ensure that the main water supply is not contaminated by impure liquid flow back into the system.

Backflow for sprinkler devices is easy to install, requires no additional pipes and fittings, and can be installed in a very short time.

The principle of operation for backflow for sprinkler devices is straightforward as they act as a double-check system. By this, the Water Supply is fed into the supply pipe from outside, and then water is dispensed through the sprinkler heads. At any one point in time, the water supply is at its highest pressure, and there is no possibility of contamination to that water flow.

Importance of Sprinkler system backflow preventers:

Plant Protection

Backflow for sprinkler systems protects not only the water supply but also the plants. This is because the water supply is not contaminated by other impure liquids, which may damage the plants.

Environment Protection

Backflow for sprinkler systems prevents contamination of our environment by harmful pollutants and pollutants from some industries such as factories, etc.

Cost Saving

Backflow for sprinkler systems can save on costs in case the supply is contaminated, and it also eliminates energy wastage.

Health Protection

Backflow for sprinkler systems ensures the water supply is protected at all times.

Easy Installation

Backflow for sprinkler systems are very easy to install, no additional piping is needed, and they can be installed in a short period.


Backflow for sprinkler systems is essential in protecting the environment and all living things around us. They ensure our water supply is uncontaminated, thus reducing the possibility of any water-related problems. Backflow for sprinkler systems can also be used in firefighting, irrigation, and many other things, depending on the flow rate and pressure needed.