Free pipe sizing program 5

[Cooky]

I have written a program which calculates the pressure drop of fluids flowing through standard sizes of pipe, from 10mm up to 3600mm in diameter.

The program also calculates useful thermophysical properties of water, ethylene glycol & propylene glycol. These properties are corrected for temperature and percentage glycol concentration, as defined by user input.

The program is based around the CIBSE method of calculating pressure drop and is based on SI units.

As the program is based on Microsoft Excel, you must enable macros for the program to function.

http://pressure_drop2.mysite.freeserve.com/

I welcome comments about the program.

Cooky.

 

[lilliput1]

A more useful spreadsheet for engineers would be one that cumulatively adds up the pipe friction losses as you follow the fluid flow through piping lenths, fittings, equipment and for open piping system only - elevation change. Say set up a spreadsheet workbook with the 1st sheet the input sheet, the 2nd sheet the output sheet and as money other sheet that would contain data or side calculations required. A user would only have to input data on the input sheet. The remaing sheets would be locked. The input sheet would have columns that would be filled out to represent a particular piping run say point A to point B. This run would be a particular pipe size (type selectable) and particular gpm. Under this column, the user would fill in ft. length, number of fittings (list types), equipment (list typical equipment & typical presure drop values that must be confirmed for each job), static head (to be overcomed for open piping systems only). The pressure drop at each column would first be calculated (in the output sheet) as equivalent length of pipe, then as ft. of water (or equivalent SI). The loss at each column would then be cumulatively added. This would be helpful to engineers to be able to calculate pump head required.

 

[lilliput1]

Also for design selection of pump duty, the clean piping loss must be factored by minimum 1.15 for closed system to maximum of about 2.0 times for aged open system with corrosion inside (old cooling tower condenser water piping). The input sheet should have a input block for this general factor. However if another factor other than 0 is inputed specifically for a column definding a particular pipe section, then this overiding factor should be used for the pipe section. This in theory would would allow simulation of existing loop with different age piping sections.

 

[quark]

Cooky!

I have been waiting for this spreadsheet since you posted your question about glycol properties in another forum and it is really good work from you, so a star.

Why is it that you prefer mass flow rate? If your calculations require mass flow rates then I would anticipate another field with volumetric flowrate input and subsequent mass flowrate calculation(I think it may not be a problem as you are already calculating density)

I have not fully gone through it at the moment but if I find anything helpful, I do let you know.

Regards,

 

[nans]

Hi Cooky

Facing difficulty opening the link …..pls help

 

[Cooky]

Hi quark,

The fluid flow can be changed from mass flow to volume flow, by using the pull-down box to the right of the cell.

nans: link is working fine, I've just tried it.

Cooky

 

[pardal]

Hi Cooky , what is the meaning of this value

equivalent length of a component for ?=1

The program works preety well.

Thanks for it.



Pardal

 

[pk786]

hi find difficult to open

 

[omak]

Hi Cooky,
I am having problems with the link, would u know why? U said u used CIBSE'S guide to create the programme, did u use loading units or the probabilty theory? Do u know of how I can find some information on the probabilty theory of appliances and how to use it to obtain pipe losses, because the guide is not very good on this one.
Thanks

 

[Cooky]

Hello Omak,

My ISP changed names, so here's the new link (they said the old link would continue to work ok).......

http://mysite.wanadoo-members.co.uk/pressure_drop2

I don't understand what you mean with the terms 'loading units' and 'probability theory', in reference to calculating pressure drop. Can you give me more detail.

Cooky

 

[omak]

Hi Cooky,
Thanks for the new link. With regrds to the claculations, if u look at how CIBSE have done their calculations,they have used what we call loading units and the Institute of Plumbing have used probabilty theory as well as loading units. The probabilty theory is based on a factor of probabilty on how appliances will be used or open at any one given time. Does this make anysense to you?
Thanks
Omak

 

[Cooky]

Omak,

Probability theory seems to be another term for diversity factor. I haven't heard the term loading units before (has anyone seen an article which explains this?).

The program uses classical methods to model fluid flow, including Reynolds, Moody, D'Arcy, Colbrook-White etc. Click the 'About this program' button on the program to see the formula I've used.

Cooky

 

[omak]

Hello Cooky,
Do u know of where I can find some infromation of setermining flow rates in house appliences sink, toilet, etc with the various scenarious like one tap being open, or 2 or all the taps at the same time?
Thanks

 

[Cooky]

omak,

The information you need is shown in CIBSE Guide G.

Cooky

 

[briand2]

Alternatively, look up BS6700, or look in the Institute of Plumbing's Plumbing Engineering Services Design Guide.

Regards,

Brian

 

[friartuck]

Hi Cooky

Excellent spreadsheet

I jhave a few suggestions if you have the time to modify the programme.

Can it be programed to print a sheet or table as per the CIBSE format. That would be super duper.

b. Would it be possible to have a 'DIY' section where a special pipe could be added. We use all the ranges ad per your calc sheet plus Mapress, Unipipe, PE pipe etc and the ID's are all different as are the roughness factors etc.

Cheers



Friar Tuck of Sherwood

 

[Cooky]

Hello Friar,

The print format is set, it would be a major re-work to modify it at this stage. I did try to show the calculated results in a CIBSE type format.

I like the idea of a DIY page, I'll probably introduce that in the next version (later this year).

Thanks,

Cooky

 

[briand2]

For an alternative (but I didn't say better!), see my offering at "

http://homepage.ntlworld.com/brian.doherty/pipesize.xls".

Feel free to comment!!!

Regards,

Brian

 

[friartuck]

Brian

Amazing

All I can say is, you and Cooky must have a masters degree in Excel and a lot of time to spare.

Some instructions wouldn't go amiss. I am working my way through the routines and will be able to give you some feedback soon.

Cheers boys and well done



Friar Tuck of Sherwood