How many psi is equivalent to 1 ft. of H2O?

• A. 0.1 psi
• B. 0.4332 psi
• C. 1 psi
• D. 2.31 psi

Answer: (B)

To determine the pressure in pounds per square inch (psi) equivalent to a height of 1 foot of water (ft. of H2O), we can utilize the hydrostatic pressure formula, which relates the height of a liquid column to pressure. The pressure exerted by a column of liquid is given by the equation:

[ P = \rho g h ]

where:

• ( P ) is the pressure,

• ( \rho ) is the density of the liquid (for water, approximately 62.4 lb/ft³),

• ( g ) is the acceleration due to gravity (approximately 32.2 ft/s²), and

• ( h ) is the height of the liquid column in feet.

Simplifying the above formula for a 1-foot column of water leads to:

1. Calculate the pressure exerted by 1 foot of water:

[ P = 62.4 , \text{lb/ft³} \times 1 , \text{ft} = 62.4 , \text{lb/ft²} ]

2. To convert this pressure from lb/ft² to psi, we use the conversion factor where 1 psi equals