The latest series of R & D Multiple’s Combination type : (Air Vacuum + Air Release Valves) amalgamates exotic features with excellent workmanship to make them the unique solution for any challenging application. Be it the filling / draining of the pipeline, on-line (under flow & pressure) air release, or the anti-vacuum function at the time of pump tripping, the ‘R & D Multiple's Bi-Stream Air Release Valve’' is the ultimate & most reliable solution.