No. The decision is based on how clean or smooth your pipe has to be to function well.

Never heard of a copper pipeline. What type of facility and flow do you have?

Compositepro:

Thanks for your reply. It is safe to say that the pipe does not need to be cleaned, even though the roughness is far increased than the clean copper pipe? I'm trying to find the literature about the value of roughness of dirty copper pipe, but still cant find one.

bimr:

Here is the explanation of the system

1. The pipe is copper pipe schedule 40
2. The long of the pipe I investigated is about 17 m.
3. The fluid transported in the pipe is water
4. K (minor losses coefficient) of the pipe system is about 47
5. Cleaning pipe is removing any surface contaminants that may be clinging to the internal wall and can possibly be dissolved or washed off.

The method I used is by calculating h_measured and h_predicted. h_measured is based on the Bernoulli equation assuming all pipe diameter is the same. h_predicted account for the minor and major losses in the pipe system. Roughness is estimated by minimizing the sum of the squared error between the measured head loss and the predicted head loss, with roughness the only parameter.