This number 16 pool plug with valve creates a tight seal for a 4 inch PVC pipe. Includes a blow through valve for inserting compressed air into lines.
Open stem plugs (or plugs with blow thru valves) use the same rubber, large wing-nuts and corrosion free materials as closed plugs except they have an opening that passes through the center of the stem. They are similar to bike tire valves. This opening allows introduction of air or water pressure into the system you are testing. This is commonly used for clearing blocked lines, blowing out lines for winterization, or pressure testing.
Safely seal off inground plumbing lines during freezing conditions! Winter freeze plugs are used to plug your swimming pool pipes after they have been drained to prevent water from entering the pipes and causing freeze damage.
