Water Supply & DistributionQuestion 40 of 360
A mechanical water hammer arrestor uses a sealed piston or bellows with a gas charge. Why is this preferred over an old-style capped air chamber?
a.It is cheaper only
b.It requires no fittings
c.Air chambers never work
d.The sealed gas charge does not become waterlogged over time, so it keeps functioning
Explanation
A traditional capped air chamber eventually absorbs its trapped air into the water (waterlogs) and stops cushioning, while a sealed piston or bellows arrestor keeps its gas charge separated and continues to function. Cost, fittings, and the claim that air chambers never work are not the correct technical reason.
Law Reference: 2022 California Plumbing Code (CPC) §609.10Practice all 360 questions free — no signup required.
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