New anti-hammer combination air valve for high-rise building is available. The importance of surge arrestors in a building is crucial to prevent damages, vibration and the problems related to the unwanted accumulation of air pockets. CSA anti hammer combination air valve will ensure the air release during working conditions, the entrance of large volumes of air in case of negative pressure conditions and the controlled outflow to avoid sudden closures and consequent water hammer with devastating effects. A typical high building lay out of FOX HR is installed at the changing slope on a riser where CSA XLC 310/410 pressure reducing valve followed by a relief unit VSM FF controls the pressure to the floor.