In-line syntactic-foam device for control of water hammer and fluid-borne noise

Abstract

Water hammer, a common problem in plumbing, is characterized by an impulsive increase in pressure. The pressure rise and associated momentum transfer may cause plumbing noise and vibration, and, potentially, catastrophic plumbing component failures. Water hammer arresters are required in building codes to be proximate to fast-acting valves, such as present in washing machines and other appliances. Commercially available water hammer arresters introduce compliance with a free-piston air spring as the means to limit the peak pressure during water hammer. Syntactic foam, comprising microspheres within a host polymer matrix, may be suitable for application in a water hammer arrester device. Foam-based arresters also enable flow-through designs, which may reduce other fluid-borne noise in addition to controlling water hammer. A prototype flow-through, in-line syntactic water hammer arrester device has been designed and tested. The flow-through design demonstrates adequate performance for service as a water hammer arrester, as well as significant insertion loss against fluid-borne noise.Water hammer, a common problem in plumbing, is characterized by an impulsive increase in pressure. The pressure rise and associated momentum transfer may cause plumbing noise and vibration, and, potentially, catastrophic plumbing component failures. Water hammer arresters are required in building codes to be proximate to fast-acting valves, such as present in washing machines and other appliances. Commercially available water hammer arresters introduce compliance with a free-piston air spring as the means to limit the peak pressure during water hammer. Syntactic foam, comprising microspheres within a host polymer matrix, may be suitable for application in a water hammer arrester device. Foam-based arresters also enable flow-through designs, which may reduce other fluid-borne noise in addition to controlling water hammer. A prototype flow-through, in-line syntactic water hammer arrester device has been designed and tested. The flow-through design demonstrates adequate performance for service as a water ham...