What does AFV mean in NASA

An Anti-Flood Valve (AFV) is a device typically found in residential and commercial plumbing systems that helps prevent flooding due to backflow or pressure surges by acting as a check valve so that water only flows out of the main supply line and not back into it.

Yes, there are various types of AFVs available such as swing check valves, poppet valves, diaphragm valves, and globe valves.

An AFV is installed onto the main line between the street connection or other source of water supply and the house. When pressure builds up on the upstream side of the valve due to backflow or pressure surges, it will open against gravity to release excess pressure and prevent flooding.

It depends on your local regulations and building codes. If you live in an area prone to floods due to storms, hurricanes, etc., then it may be mandatory for you to install one for safety reasons. In any case, having an AFV can provide protection from costly plumbing damages caused by flood water entering your home.

You can purchase an AFV from most hardware stores or online retailers that specialize in plumbing supplies. Make sure you get one that's compatible with your system's specific requirements such as size, material type, etc., so it fits properly without any leaks.