Feet of Water Column

Foot of Water Column (ftWC) is an American and English low value pressure unit, now used mostly in the USA where feet and inches are the standard units for measuring distance. 1 foot of water column at 4 degC (39.2 degF) equals 2989.07 pascals.

The main use for the feet of the water pressure unit is to measure fluid level in a tank or depth in a liquid such as sea water. Water is the most common liquid found on Earth and the density of all other types of liquid are referenced and compared to the density of water. If the specific gravity (ratio of density comparison with water) of a certain liquid is known, it will be possible to convert the required height range into feet of water to make it possible to select the correct hydrostatic range for a liquid level measurement device.