Experimental study on reducing water hammer effects in uPVC pipes using rubber bypass tubes

Abstract

Applying bypass (parallel) flexible tubes made of rubber was studied for the first time, affixed on an uPVC pipeline upstream of a regulation valve, to mitigate water hammer effects by employing simple and readily available tools. Ninety-two experiments were conducted to analyze the influence of the flexible tubes' elasticity Modulus, lengths, and inner volumes. The results demonstrate that implementing bypass rubber tubes substantially reduces the head rise (ΔH), even for shorter tube lengths. The reduction rate of ΔH shows an initial rapid decline followed by a gradual decrease as the tube length increases. Besides, the bypass rubber tube utilization significantly reduced the hammer celerity and increased both the water hammer's characteristic time and the damping rate of the hammer. The elasticity Modulus of the rubber tube exhibits a significant effect on ΔH, displaying a reverse relationship. Finally, ΔH decreases as the inner volume of the rubber tubes increases.