4 replies to this topic

[AyrtonB]

Hello everyone,

 

I am trying to do pipe sizing for my design project, I am taking the approach of calculating the capital and operating costs of different size diameters for a set flow, then summing the CAP & OP-EX (Capital costs will be spread over 5 years).

 

I am currently at a bottle neck where I require estimates of pipe costs for different diameters and materials, any help in finding these would be greatly appreciated.

 

Ayrton

[Art Montemayor]

Ayrton:

 

You state that you are “calculating the capital and operating costs of different size diameters for a set flow”.  If you have “set” the flow, I presume you mean that you have a constant flow rate at fixed conditions of temperature and pressure.  If this is not the case, then you should clearly state it because a set flow rate for any fluid requires only one size of acceptable pipe.  There is no logical sense in considering sizes other than the one calculated for the given flow.  If that is not what you mean to explain, then clearly and concisely state what you mean.

 

You also state that “Capital costs will be spread over 5 years”.  Do you mean that the piping capital installed costs will be depreciated over a period of 5 years?  Although this seems a very fast depreciation, how does this play a role in your determination of the correct pipe size?  I don’t understand what your scope of work is.  Perhaps you are meaning to find an optimized piping size for a specific project scope of work?

[AyrtonB]

Dear Art,

 

Apologies for the ambiguous description. I have a volumetric flowrate of liquid solvent (1828 m3/hr) at as you say at a set pressure and temperature (318K & 3.5 bar). I'm slightly confused by the context you use depreciation in, I am used to using depreciation to describe the loss in value of capital over time, I am trying to say that the upfront CAPEX will be paid off over a period of 5 years (this is a nominal time period, will probably settle on ca.10 but need to read more literature).

 

"Perhaps you are meaning to find an optimized piping size for a specific project scope of work?" - That is indeed my intent, I am creating a Matlab model which when given a fluid flowrate and physical parameters calculates the energy costs (from pumping) as well as capital costs (of pump & piping), it then splits the capital costs over a set pay-off time and calculates an annual cost alongside an annual energy cost. These costs will be calculated for a range of diameters and the diameter which has the lowest total cost will be chosen.

 

Ayrton

 

 

[AyrtonB]

To clarify my initial question further, the different diameters and materials I am trying to find prices for range from 2" to 36" of initially 310 & 316 steel but if possible carbon steel too

[breizh]

Hello Ayrton ,

Probably good to read this document .

Good luck.

Breizh