Anderson Manufacturing WDP150 Winter Duck Plug Valve;

Allows plumbing lines to be winterized without draining the pool. The patent-pending duck-bill valve allows a large flow of air and water to be blown from the return plumbing but does not allow water back into the linesFeatures. Install plugs into all lines. The double-seal system provides a water tight seal at the face plate or inside the fitting. Use a blower to clear all lines. The Winter Duck Plug provides adequate back pressure to allow all returns to be cleared at the same time without burping.. Once all returns have been bubbling for several minutes turn off the blower. Water will not enter the pipes from the pool. Add optional antifreeze to lines and turn on the blower again until you see some antifreeze blown into the pool. Install yellow safety caps for added piece of mind and protection against ice movement