# How Do You Calculate Variable Water Pressure in Pipes?

• metroactus
In summary, you need to calculate the pressure required to pump a fluid through a given pipeline using the general energy equation.
metroactus
ive scanned about 200 closely relevant posts to make sure I am not one of those "here we go again" posts, but can find no basic water pressure formula. Specifically I need to calculate variable hypothetical water pressures (with a final conversion to GAUGE pressure) with a known INLET PSI, comparing pipe size, pipe configuration, change in elevation, etc. Short of a hundred bucks for an engineering book, i can't find this exact formula though a lot are close. I have my constants for friction loss, gravity, inlet psi, angled and reduced pipe fittings, but need the equation that ties all these together to constantly reference as i mix and match to achieve the highest psi possible, or at the least, economically feasible.

metroactus said:
ive scanned about 200 closely relevant posts to make sure I am not one of those "here we go again" posts, but can find no basic water pressure formula. Specifically I need to calculate variable hypothetical water pressures (with a final conversion to GAUGE pressure) with a known INLET PSI, comparing pipe size, pipe configuration, change in elevation, etc. Short of a hundred bucks for an engineering book, i can't find this exact formula though a lot are close. I have my constants for friction loss, gravity, inlet psi, angled and reduced pipe fittings, but need the equation that ties all these together to constantly reference as i mix and match to achieve the highest psi possible, or at the least, economically feasible.

Here are some formulas complements of Q_Goest a few posts below...

CS

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• Pipe-Flo Pro.pdf
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Hey, that looks familiar! lol

I have a link to your post Q. It comes in handy quite often.

To pumping crude oil (0.9 SG) with distance for 72 km on 8" steel pipe with flow rate as 725GPM and my question is how much the pressure (psi) to do this work ?

b4123p said:
To pumping crude oil (0.9 SG) with distance for 72 km on 8" steel pipe with flow rate as 725GPM and my question is how much the pressure (psi) to do this work ?

You need to provide more information. A sketch would be helpful. Make sure to note elevation changes, pipe schedule, etc...

You can apply the general energy equation for fluid flow to find the required pressure once you determine the system layout.

CS

## 1. What is the basic water pressure formula?

The basic water pressure formula is P = F/A, where P represents the pressure in Pascals (Pa), F represents the force in Newtons (N), and A represents the area in square meters (m^2).

## 2. How is water pressure measured?

Water pressure is typically measured using a device called a pressure gauge, which measures the force exerted by the water on a specific area.

## 3. What factors affect water pressure?

The factors that affect water pressure include the height or depth of the water source, the force of gravity, the density of the water, and the temperature of the water. In addition, the diameter and length of the pipe carrying the water can also impact water pressure.

## 4. How can the basic water pressure formula be applied in real-life situations?

The basic water pressure formula can be used to calculate the water pressure in a plumbing system, as well as in hydraulic systems such as car brakes and heavy machinery. It can also be applied to determine the pressure needed to pump water to a certain height or distance.

## 5. How does water pressure affect the flow rate of water?

Water pressure and flow rate are directly related. As water pressure increases, the flow rate also increases. This means that the higher the water pressure, the faster water will flow through a pipe or system. However, other factors such as the size and length of the pipe can also affect the flow rate.

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