What is required to be installed on a sump pump's discharge pipe to prevent backflow?

The installation of a check valve on a sump pump's discharge pipe is crucial to prevent backflow. A check valve is designed to allow fluid to flow in one direction while preventing it from flowing back in the opposite direction. This functionality is essential in sump pump systems because, during heavy rain or flooding, water is pumped from the sump pit to prevent flooding in basements or low-lying areas.

If the water were to flow back into the discharge pipe due to changes in pressure or any backflow conditions, it could undermine the purpose of the sump pump, leading to potential flooding and water damage. By using a check valve, you ensure that once the water is expelled from the sump pit, it cannot return, thus maintaining the integrity of the drainage system and protecting the property from water intrusion.

The other options, while they have their specific uses within plumbing systems, do not provide the same function as a check valve. A ball valve can stop or start the flow of water but does not prevent backflow. A gate valve is used for on/off control rather than flow prevention and can be difficult to seal completely, which may not effectively stop backflow. A pressure relief valve is primarily meant to relieve excess pressure in a system rather than to control