Question 431General Subjects - Assistant Engineer

The correct answer is C) an air-cushion in the hydro-pneumatic tank. The potable water system on many vessels maintains a constant pressure range through the use of a hydro-pneumatic tank that contains an air-cushion. The air-cushion in the tank acts as a shock absorber, compressing and expanding to regulate the pressure and prevent rapid pressure fluctuations in the system. This ensures a steady supply of potable water at the desired pressure, without the need for constant speed or variable speed supply pumps or a pressure regulator. The other options, such as using constant speed pumps (A) or a pressure regulator (D), would not provide the same level of pressure regulation and stability as the air-cushion in the hydro-pneumatic tank.