Different Types of Backflow Preventers that You Should Know About

backflow prevention installation inspection

Backflow is a term that refers to the unwanted reverse flow of any liquid, solid, or gas into the potable piping system. You can get backflow prevention installation services from experts like Apna Fire & Electrical Ltd. They are experts in installing and maintaining backflow preventers. But, do you know that there are various types of backflow preventers that are used in the market. We have created a list of different types of backflow preventers. You can read about them below. But, before that, we want to provide you with information about two forms of backflow.

Also read: Some Common Backflow Preventer Installation Mistakes

Forms of Backflow

There are mainly two forms of backflow. They are back-siphonage and backpressure. We have discussed briefly about them below.

  • Back-siphonage: This type of backflow occurs when contaminants are pulled into the potable water supply. The main reason for this to happen is due to a broken water main or when nearby fire hydrants are in use. The materials are pulled into the water line due to pressure.
  • Backpressure: The backpressure backflow happens when contaminants are pushed into the potable water supply. Another reason for backpressure backflow is when there is a loss of pressure in the potable water supply, similar to the scenarios described for back-siphonage. The increased pressure on the non-potable supply, like heat from a boiler or pump, also causes this to happen. So, if the downstream pressure exceeds the supply pressure which is possible without backflow prevention installation services,then there will be a chance to have backpressure.

So, these are two forms of backflow. Now, let us discuss different types of backflow preventers.

Types of backflow preventers

There are five types of backflow preventers available in the market. We have created a list below. You canconsult with a backflow prevention installation services provider about these types.

  1. Anti-Siphon Valve: In this type of valve there is aspring-loaded flap. It works in a single direction.
  2. Pressure Vacuum Breaker: This type of backflow preventer has one check valve and one air inlet valve. The shut-off valve and test cocks are also equipped witha pressure vacuum breaker. This can be effective against back-siphonage.
  3. Atmospheric Vacuum Breaker: This type of backflow preventer is a vertical, physical separation between the end of a water supply outlet and the flood level rim.
  4. Double Check Backflow Preventer: This type of backflow preventer device has two check valves in a row. You will not find any vent to allow air to enter the lines or allow water to exit. It makes use of tight seals to prevent backflow.
  5. Reduced Pressure Backflow Preventer: This is also a mechanical backflow preventer that is equipped with a shut-off valve and test cocks. It also has two independent check valves and a pressure differential relief valve. 

So, these are different types of backflow preventers that are commonly used. You can get backflow prevention installation services from experts. This is because the experts will provide you with the correct information about backflow preventers installation. You need to remember that not all types of backflow preventers are installed for all types of applications. Once you identify plant locations where backflow can occur, then you can get backflow prevention installation services and install the correct backflow preventers for the system.


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