PVC Single Union Ball Valves are also referred to as dump valves or end of line valves. As the valve has just one union connection for demounting and repair it is not recommended for use within a pipeline but at the end of a pipeline. PVCu Single Union Ball Valves are batch tested 1 in 1000. The valves are available as PVCu Single Union Ball Valves with plain ends for solvent cement gluing in imperial and metric sizes. We also stock BSP threaded PVC Single Union Ball Valves.