Which device is typically installed as surge protection and can be an air chamber or surge tank?

• A. Filter cartridge
• B. Pressure reducing valve
• C. Air chamber or surge tank
• D. Flow meter

Answer: (C)

The main idea is protecting a piping system from pressure surges that happen when flow changes abruptly, such as when a pump starts, a valve closes quickly, or there’s a sudden demand change. An air chamber or surge tank does exactly that by providing a cushion in the water column. The trapped air in an air chamber compresses as pressure rises, absorbing part of the energy of the surge so the pressure spike isn’t as high. In larger systems, a surge tank serves the same purpose on a bigger scale, storing some of the water and damping the transient pressure waves.

That’s why this device is the best choice for surge protection: it directly moderates pressure transients rather than altering pressure downstream, measuring flow, or filtering impurities. The other options have useful roles (filters remove particles, a pressure reducing valve lowers steady downstream pressure, a flow meter measures flow) but they don’t absorb or cushion sudden pressure surges in the way an air chamber or surge tank does.