Atmospheric type vacuum breaker

A very specific and technical topic!

An atmospheric-type vacuum breaker is a type of valve used in plumbing systems to prevent backflow and siphoning of water. Here's a breakdown of what it is and how it works:

What is an atmospheric-type vacuum breaker?

An atmospheric-type vacuum breaker is a type of check valve that allows water to flow in one direction (from the potable water supply to the fixture or appliance) while preventing backflow or siphoning of water in the opposite direction. It is designed to operate at atmospheric pressure, hence the name.

How does it work?

The valve consists of two main components:

  1. Spring-loaded check valve: This is the primary component that prevents backflow. It is designed to close when the pressure in the system drops below a certain threshold, typically around 1-2 psi (pounds per square inch).
  2. Atmospheric vent: This is a small opening that connects the valve to the atmosphere, allowing air to enter the system when the pressure drops.

Here's the operation:

  1. When the water supply is turned on, the check valve opens, allowing water to flow from the supply to the fixture or appliance.
  2. If the pressure in the system drops due to a sudden change in demand or a blockage in the line, the check valve closes to prevent backflow.
  3. As the pressure drops, air enters the system through the atmospheric vent, which helps to equalize the pressure and prevent siphoning.
  4. When the pressure returns to normal, the check valve reopens, allowing water to flow again.

Benefits and applications

Atmospheric-type vacuum breakers are commonly used in:

  1. Plumbing systems: To prevent backflow and siphoning in residential, commercial, and industrial plumbing systems.
  2. Water heaters: To prevent backflow and contamination of the potable water supply.
  3. Boilers: To prevent backflow and siphoning of water in boiler systems.
  4. Fire protection systems: To prevent backflow and contamination of the potable water supply in fire protection systems.

In summary, an atmospheric-type vacuum breaker is a critical component in plumbing systems that helps to prevent backflow and siphoning of water, ensuring the safety and integrity of the potable water supply.