Flow Rate from Pressure 1

[hungrydinosaur]

Hi All,

Is it possible to find the flow rate from Pressure and Pipe ID? I need to find the flow rate for a pressure of 2000 psi, with a pipe ID of 0.25 in.

Thanks,

HD

 

[LittleInch]

You need pressure drop per unit length for a liquid and pressure drop over a total length for a gas.

Pipe ID of 0.25" is rather small for a lot of the free calculation tools and may not be accurate.

Any fluid at a static pressure will not flow....

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[zdas04]

You also need a downstream pressure and pipe length.

0.25 inch ID tubular goods are typically in the category of "capillary flow" which excludes them from any of the incompressible flow equations for gas (pressure drop per unit length is too high in turbulent flow and the inocmpressible-flow equations do not work in laminar flow) and excludes them from most of the equations in liquid flow (the ratio of boundary layer thickness to pipe ID makes the flow surface-tension dominant instead of friction dominant).

David Simpson, PE
MuleShoe Engineering

Law is the common force organized to act as an obstacle of injustice Frédéric Bastiat

 

[hungrydinosaur]

Zdas/Littleinch,

Thanks for the replies. This is a hydraulic oil flow. I have changed the parameters during my design, and the diameter is 0.375" and 1000 psi. Is there any way out to calculate the flow rate here? Any commonly used formula with which I can make an approximate guess?

Thanks.

HD

 

[katmar]

Provided that you can define the pressure difference between the supply and return, there certainly are formulas that you can use. Search for "Darcy-Weisbach" and you will find thousands of references. But hydraulic oil hoses are usually sized using charts and tables based on typical velocities rather than on pressure drops. Searching for the term "sizing charts hydraulic piping" will find them. At 1000 psi they seem to limit velocities to around 10 ft/sec. A pipe of 0.375" ID would deliver 3.4 USGPM at 10 ft/sec.

These velocities are based on the experience of the suppliers. A run of the mill piping engineer would never size a small pipe like this for a velocity of 10 ft/sec. For a continuous duty a velocity of 2 or 3 ft/sec would be more normal. Call in the rep of your hydraulics equipment supplier and get their advice.

Katmar Software - AioFlo Pipe Hydraulics

http://katmarsoftware.com

"An undefined problem has an infinite number of solutions"

 

[racookpe1978]

He still hasn't told you his length, has he? No connections, branches, elbows, fittings, or valves, either?