Pop-Up drainage emitters act as the discharge point of a drainage system, opening easily when needed to allow water to flow freely from the pipe and away from structural foundations. The patented spring-loaded cap opens with the hydro-static pressure of water flowing through the drainpipe, then closes as the flow diminishes. Use with 4" Schedule 40 PVC pipe and fittings. Shop the selection below! Don't see what you're looking for? Send us a message.