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 3" & 4" Schedule 40 PVC pipe and fittings. Shop the selection below! Don't see what you're looking for? Send us a message.