# Water Column

Hello, my question is, dose any one know how much p.s.i. 40 inches of water column is? We made some pipe at work which is attached to a rather large fan
and the air going through it is measured in water column and being a welder I relate to every thing in p.s.i. I would like to know if it a lot of pressure? Thank you Ed
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1 atmosphere is 33 feet of water or 14.7 psi that makes the conversion 27 inches of water = 1 psi.
Your 40 inches of water is about 1.5 psi. As in NOT a lot of pressure.
Ed Atyeo wrote:

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Let's see if I can calculate it :
40 inches / 12 = 3.333 Head feet.
3 HF = 1.203 P.s.i. .3 = 1.302 * .1 = .1302 .03 = 1.302 * .01 = .01302
Therefore 40 inches = 3.33 Head feet = 1.346 psi If I did it correctly.
Water is 62.5 # / cu ft.
As an example, 85.3 ft is 37.02 p.s.i.
Martin Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member
Ed Atyeo wrote:

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The calculation is simple if you know the density of water.
PSI = pounds per square inch
The question then is how many pounds does a colum of water 40 inches high, with a cross section ('footprint') of 1 square inch have?
If the above post is correct and water has a density of 62.5 pounds per square inch, then a one square inch colum that is one foot high has a weight of 62.5 / 144 = 0.434 pounds. (144 is the number of square inches on the base of a cube one foot on each side).
Hence, a 40 inch colum has a weight (per square inch) of 0.434 x 40 / 12 = 1.446 pounds.
G
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Well water is actually 62.43 but who is counting.
The table in my "Handbook of Applied Mathematics" listed 62.5 (assumed it states)
Glen was requiring specifics - but missed my typo.
the 3 HF = 1.302 as used below it twice over. I listed 1.203.
Then our numbers come out exactly.
The table of ten numbers were carried with plumbers (mostly big cities) and simple math was needed. - Shifting the decimal point and adding are needed.
Martin Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member
Martin H. Eastburn wrote:

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Thanks guys it is much appreciated........Ed

water
fan
welder
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