Standard Series True Union Ball Valves (3/8" to 4", PVC) Heavy Duty Construction: Standard Series True Union Ball Valves are designed for medium duty industrial and commercial applications. True Union Design: This makes these valve very easy to maintain by allowing for easy removal from a piping system without breaking down piping connections. Just unscrew the two assembly nuts and lift the valve body out of the line. Never a Problem with Corrosion: This is because of the valves all plastic construction. They will never rust or corrode...and they can survive corrosive environments without the need for painting or expensive epoxy coatings. Cost Effective Design: Cepex by Hayward Standard Series True Union Ball Valves are the valves of choice for medium duty, cost sensitive applications in all industries.