Profile: Durlmark Industrial Inc. offers an extensive range of pipe, valves, flanges, pipe fittings, fasteners, gaskets and other spare parts. Our products are API and CE (TUV) certified, and are widely used on oil rigs. We are an ISO 9001:2008 certified company. A ball valves is a form of quarter-turn valve which uses a hollow, perforated and pivoting ball also called as a ?floating ball? to control flow through it. It is opened when the hole of ball is in line with the flow and closed when it is pivoted 90-degrees by the valve handle. The handle lies flat in alignment with the flow when opened and is perpendicular to it when closed, making for easy visual confirmation of the valve?s status.