plumbingequipmentengineeringmaintenance
Why do splash pad systems need air relief valves?
Quick answer
Air relief valves at high points in the plumbing automatically vent trapped air that accumulates from pump cycling, dissolved-gas release, and refilling after maintenance. Trapped air reduces flow, causes water hammer, and can cause nozzles to spit. Inspect annually and replace stuck valves.
Air relief valves (also called air vents or vacuum breakers in some configurations) are essential at high points throughout splash pad plumbing. Air accumulates from several sources: pump start-up cycles draw air through gland seals; dissolved gases release as water warms; and any maintenance involving pipe drain-down introduces air on refill. Trapped air compresses unevenly, reducing effective flow rate, causing water hammer when flow restarts, and producing erratic spray patterns where nozzles sputter and spit. Air relief valves are float-actuated devices that vent air automatically while keeping water in. Standard practice: install at every high point in the supply manifold, after the pump on the discharge side, and at the top of the surge tank. Inspect annually for stuck floats, debris in the vent port, and freeze damage. Replace failed valves immediately — they cost $20-$80 each and prevent expensive water-hammer pipe damage.