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Guru
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Roughness Factor of Pipe

09/29/2012 8:08 AM

Roughness Factor is required for pressure drop calculations in compressed gas flow through piping. On search for carbon steel pipe I mostly get this ranging from 0.045 to 0.090 mm. For cast bronze pipe I could not get. Can some one help to give closer values of Roughness Factor for the following pipes:

1. Carbon Steel seamless

2. Carbon Steel welded (ERW)

3. Carbon Steel seamless, pickled

4. Cast Bronze (looking rough compared to CS)

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Pathfinder Tags: Pipe roughness factor
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Guru

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#1

Re: Roughness Factor of Pipe

09/29/2012 9:37 AM
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Guru
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#3
In reply to #1

Re: Roughness Factor of Pipe

09/30/2012 5:29 AM

I posted my question after searching these links. The problem is that there is no uniformity. Different links give different figures. As I pointed out that for carbon steel most of the links give 0.045 to 0.090 mm. For stainless steel many links give 0.015 mm. One other link give 0.061 mm for both.

Your 2nd link give 0.045 mm for both carbon steel and SS, 1st link give 0.02 to 0.05 and 0.03 mm (almost same).

So, I am confused, what to take.

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Guru

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#4
In reply to #3

Re: Roughness Factor of Pipe

09/30/2012 6:24 AM

Does not the relevant ASTM/ANSI code specify roughness factor for pipes?

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Guru
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#5
In reply to #3

Re: Roughness Factor of Pipe

09/30/2012 9:24 AM

Welcome to the real world.

Unless you perform tests on the specific pipe you will use, the relative roughness will never be known. Not all pipe is identical, thus different numbers are obtained during testing.

Either ask your pipe supplier, or pick a value and go with it. Without any specific information, pick the worst case value and get on with it.

If that's not good enough, have your pipe tested.

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Luck comes and goes. Skill is forever. Intelligence either is, or it ain't. lyn
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Guru
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#7
In reply to #5

Re: Roughness Factor of Pipe

10/01/2012 10:06 AM

Agreed. GA.

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Guru

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#6
In reply to #3

Re: Roughness Factor of Pipe

10/01/2012 2:33 AM

There are formulas, if one can DIY.

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Power-User
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#2

Re: Roughness Factor of Pipe

09/30/2012 5:04 AM

pritam

hope that this does not get graded as "Off Topic"

Many years ago we had a project that needed a very smooth pipe and a team was sent to investigate lining of the pipes with plastic.

I seem to recall, only that they were largely succesful - but can remember no details at this remove.

Sorry

Sleepy

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