PVC Internal Waterstop Without Valve is a type of waterstop that is used to prevent the passage of water through concrete joints in construction projects. It is made of PVC material and is designed to be installed within the concrete joint before the concrete is poured. The waterstop creates a barrier that prevents water from passing through the joint, which helps to ensure the durability and longevity of the structure. The version without a valve means it doesn't have a feature that allows for the release of built-up water pressure.