PHB Type High Back Pressure foam makers are classified as Type II discharge devices in accordance with NFPA Standard 11. When used with properly expanded fluoroprotein type low expansion foam, these foam makers can provide application of the foam through the product directly onto the fuel surface with a minimum of fuel pick-up and saturation of the foam bubble. Using PHB Type High Back Pressure foam makers with fixed discharge outlets has the added advantage of directing the entire flow to the hazard area, regardless of weather conditions, for the most effective utilization of foam resources. The PHB Type High Back Pressure foam maker produces foam by introducing air into the foam solution stream. The solution inlet of the foam maker is fitted with a factory installed orifice, designed to control the flow rate and create a reduced pressure area to draw air into the foam solution stream.
Air is drawn into the foam solution through an air inlet hole located on the foam maker.
To prevent obstruction, the air inlet is protected with an air inlet strainer with a stainless steel screen. A turbulator tube aids in the mixing of the air into the foam solution to provide the proper foam expansion. The aerated foam is discharged directly into the product at the base of the tank or the product supply pipeline to the tank. The PHB Type High Back Pressure foam maker is designed for easy, low cost installation on Cone Roof storage tanks. In addition to subsurface injection to cone roof tanks, PHB foam makers are often used for dike protection in the event of a product spill.