roughness data for pipe
roughness data for pipe
(OP)
hello everyone,
i'm working on a list of pipe materials for which i need to find the roughness values, for use in a pressure loss calculator.
I've done quite some research, including here, and i was surprised to see that:
A. It's hard to find that kind of info
B. Values are different, depending on the source
For example, in the Toolbox, I found a value for stainless steel to be 6E-4 inch, another source tells me 1.8E-3.
For PVC, i found a value of 84E-5. A supplier's source gives me 7E-5.
Anyway, I'm hoping someone could help me out finishing my list by providing me with the Ra values for (or a link to a good source):
Galvanized steel
Zinc plated steel
Cupper
And, I also have a bunch of plastic lined steel pipes. Is it correct to assume the values for the plastic to be used in the case of lined pipes?
Thanks a lot for your insights!
i'm working on a list of pipe materials for which i need to find the roughness values, for use in a pressure loss calculator.
I've done quite some research, including here, and i was surprised to see that:
A. It's hard to find that kind of info
B. Values are different, depending on the source
For example, in the Toolbox, I found a value for stainless steel to be 6E-4 inch, another source tells me 1.8E-3.
For PVC, i found a value of 84E-5. A supplier's source gives me 7E-5.
Anyway, I'm hoping someone could help me out finishing my list by providing me with the Ra values for (or a link to a good source):
Galvanized steel
Zinc plated steel
Cupper
And, I also have a bunch of plastic lined steel pipes. Is it correct to assume the values for the plastic to be used in the case of lined pipes?
Thanks a lot for your insights!
Process - Piping
ing - EiT





RE: roughness data for pipe
My fluids books lists the equivilent roughness for new galvanized iron at 0.0005 feet. Don't know if that's helpful or just another data point that may be different than others you will find.
Book is "Fundamentals of Fluid Mechanics" by Munson, Young, Okiishi.
-- MechEng2005
RE: roughness data for pipe
RE: roughness data for pipe
For SS, I usually use the same as commercial steel - from Crane that is .05mm (.002in), which is close enough to the 1.8E-3 quoted above. Zinc plated steel is probably close enough to commercial steel also.
Cheers,
John
RE: roughness data for pipe
What about dirty, corroded, eroded pipes? That will be "normal service" conditions after only a few months though, right?
RE: roughness data for pipe
Can we assume the value for galvanized iron to be close enough to that for galvanized steel?
@racookpe:
ours are pipes to be used in clean environment (semicon, photovoltaic). They're not supposed to get dirty.
Process - Piping
ing - EiT
RE: roughness data for pipe
"We don't believe things because they are true, things are true because we believe them."
RE: roughness data for pipe
RE: roughness data for pipe
Process - Piping
ing - EiT