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# Standing Head Pressure in PSI

06/04/2008 7:06 PM

I need to find the standing head pressure in psi of water in a pipe I am hydrostaticly testing......any help?

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#1

### Re: head pressure

06/04/2008 10:23 PM

Regards JD.

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#2

### Re: Standing Head Pressure in PSI

06/05/2008 11:08 PM

2.7 psi per vertical feet of elevation in your pipe.

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#7
In reply to #2

### Re: Standing Head Pressure in PSI

06/09/2008 5:05 PM

I thought it was 2.31 vertical feet per psig but I am probably wrong again.

Thanks

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#11
In reply to #7

### Re: Standing Head Pressure in PSI

06/13/2008 10:10 PM

Literally you are correct but a little "Murphy" does not hurt. As a fast rule of thumb is use 3'.

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#3

### Re: Standing Head Pressure in PSI

06/06/2008 1:32 AM

A rule of thumb I use in my trade is .433 lbs./ft. If you know the height of your water column, head pressure is easy to determine.

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#4

### Re: Standing Head Pressure in PSI

06/06/2008 10:54 AM

The density of water is 0.0361 lbs per cubic inch. Convert you height into inches, and multiply by 0.0361 and you will get lbs per inch squared head pressure. This will give you a more accurate value, for example, 2.31ft has a head pressure of 1.000692 psi.

Head pressure of 12' of water;

12' = 144"
144" x 0.0361 lbs/cubic inch = 5.1984 lbs/inch squared

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#5

### Re: Standing Head Pressure in PSI

06/06/2008 11:21 AM

number one has the best answer so far. the one i use, is that 100 feet of head gives approximatly 35 psi, which is what municipalities try to supply.

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#6
In reply to #5

### Re: Standing Head Pressure in PSI

06/06/2008 11:28 AM

In my line of work, those extra decimals in my equation are vital. We cannot afford to approximate anything. Once we do that, bad things happen.

100' is more than 35 psi

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#8
In reply to #6

### Re: Standing Head Pressure in PSI

06/11/2008 2:15 PM

i stand corrected. thank you. so, what is the psi at 100'?

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#10
In reply to #8

### Re: Standing Head Pressure in PSI

06/13/2008 9:28 AM

100' x 12 = 1200"

1200" x 0.0361 lbs/cubic inch = 43.32 psi

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#9

### Re: Standing Head Pressure in PSI

06/12/2008 9:24 PM

I do a fair amount of hydro testing of boilers & pressure vessels. Some as high as 170 feet. The accepted standard in and around my industry is the .433 / foot.

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### Users who posted comments:

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