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Hello, I need to choose the righ

Hello, I need to choose the righ

Hello, I need to choose the righ


I need to choose the right pipe diameter knowing the flowrate. is there a minimum gas velocity and a maximum gas velocity standardized to be respected?

Thank you

RE: Hello, I need to choose the righ

No minimum.

Maximum depends on many things such as cleanliness, any liquid particles, length of pipeline / pipe, required or max pressure drop etc etc

Velocities could be realistically anything from 10 to 40 m/sec depending on your design code / standard and the issues noted above. Erosion can become your limiting factor, but then you need to decide how to calculate this. Many methods are inherently conservative. you need to know min and max pressures to be able to calculate actual density and velocity in the pipe. Any gas calculation needs that (pressure and density), you can't do it based on standard flowrates alone.

The issue of maximum fluid velocities is a contentious issue with many people stating figures plucked from thin air or written in different codes, standards and company recommended practices.

The vast majority are simply guidance.

There is never a "right" diameter. Only one which on balance satisfies the competing issues including cost, schedule and physical issues. Everyone has a different weighting for these issues so comes up with different answers.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Hello, I need to choose the righ

As an addendum to LI's post, there actually IS a minimum when sizing for pneumatic conveying. Likely not what the OP is looking for, but the OP's post was bereft of details.

RE: Hello, I need to choose the righ

Agree with TiCl4, there is no point answering this query as there is so little to go on. For example, is the pipe 12-Inches long or 2 miles?

RE: Hello, I need to choose the righ

He or she doesn't respond very much based on past posts....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Hello, I need to choose the righ

You need to calculate always with the critical minimum pressure and maximum flow.

After that I don’t know a limit of velocity. For example I know that ultrasonic meters you need to have a velocity as minimum 3 ft/sec and maximum 85 ft/sec

But for example in a main pipeline in Mexico our energy regulatory committee says that maximum is 20 meters/second but in the company our number is 12 m/sec it’s depends the parameters that use your company I think.

RE: Hello, I need to choose the righ

Yes. Most Owners will have their own project standards built on years of experience. If none, follow the global industry standards.


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