The Mod. VDP is a deviator valve used to facilitate the testing of foam systems like those protecting the fixed or floating roof tank. The device prevent the foam flow from being discharged on the tank or within the protected area. Inside this testing valve, a movable shutter diverts, for duration of the test, the flow of the foam solution to a lateral outlet, preventing the foam solution to reach the foam chambers or pourers. The deviator valve can be flanged 3 “, 4” or 6 “UNI or ANSI. The Mod. VDP is available in brass material, suitable for industrial water, sea water and foam concentrate using.