A bladder tank concentrate controller may be used for small open head foam/water deluge systems.  A more economical choice would be the use of an eductor system with an atmospheric storage tank.  This system is less expensive than the bladder tank system and easier to install on small deluge systems.  The eductors are designed to produce a strong venturi effect (vacuum) as a given flow range of water passes through the eductor.  The venturi effect causes the concentrate from the concentrate storage tank to be educted into the flow of water. The foam concentrate is stored in an atmospheric pressure container unlike the bladder tank. The container can be located at an elevation lower than the eductor (see eductor technical data sheets for more specific information).  The eductors require a minimum of 35% pressure loss across the device in order to produce the proper venturi effect.  Please refer to technical data sheet for additional information, or contact Viking’s Technical Services team at 877-384-5464 / techsvcs@vikingcorp.com.