Rhode Island Journeyman Plumber Practice Exam

What is the proper calculation for pressure at the base of a vertical stack?

1. Height times specific weight

2. Square footage times height

3. Height divided by pressure

4. None of the above

The correct answer is: Height times specific weight

The correct calculation for pressure at the base of a vertical stack is determined by multiplying the height of the fluid column by its specific weight. This relationship stems from the principle of hydrostatics, which states that the pressure at a given depth in a fluid is proportional to the height of the fluid above that point and the specific weight of the fluid. Specific weight is defined as the weight of the fluid per unit volume. When you multiply the height of the fluid column by its specific weight, you obtain the hydrostatic pressure exerted at that depth. This is a fundamental concept in fluid mechanics and is crucial for accurately calculating pressures in plumbing systems. The other options do not accurately reflect the correct relationship needed to determine the pressure at the base of a vertical stack.