15 replies to this topic

[Sherif Morsi]

Dear All,

I have compiled two spreadsheets for single phase line sizing (Liq & Gas) based on API RP 14E.
The spreadsheet also accounts for pressure drop calculation and difference in head (for liquids).

Pressure drop due to fittings, valves and and friction are also considered.

You are kindly invited to download the two sheets and use them.
Your review, opinion and critics are most welcome.

Best Regards,
Sherif

Attached Files

•  Gas Lines Sizing.xlsx   86.21KB   1423 downloads
•  Liq Line Sizing.xlsx   98.21KB   1375 downloads

[Sherif Morsi]

Any comments so far?

Please reply

[Art Montemayor]

Sherif:

You have done good work and you deserve to be complemented.

However, you have only given us a weekend to receive, review, and write down comments. And this is a weekend that we normally spend with family - especially on religious occasions (like this one) for some of us. I am very impressed by the effort and the obvious importance of an engineered document such as this one and I would like to spend some time reviewing and studying it so that I can comment on it.

I have already made some superficial comments - such as a need to identify the engineering author of the calculation, the date done, the Title of the Calculation, etc., etc. I will continue to work on it, but this week is a religious event for our home and I will probably submit my comments in a week.

[Sherif Morsi]

Art,

Well...You are probably right People need time to be able to comment on it.
Happy Easter and I wish you good times with your family, one always needs occasions like these from time to time.

I will be waiting for your comments

Sherif

[sundeepgupta123]

<sub>Hi Guys,

Can you all post me any article which has equations for gas phase pressure drop in various conditions.

Appreciate your response.

regards</sub>

[Sherif Morsi]

Hi sundee,

The pressure drop equation used in the spreadsheet is a general pressure drop equation and can be used for various applications.

[Sherif Morsi]

Any comments yet?!!

[Chris Haslego]

Let Art and the others take some time to review them. With some feedback and modification, perhaps we'll include them in the download section too.

[Art Montemayor]

Sharif:

I have made some insertions into your Gas line sizing spreadsheet. You have made it very difficult to give you any meaningful comments and remarks on your spreadsheet because you have locked it. I am unable to see your algorithm or make any callouts on your spreadsheet.

No serious engineer is going to give you his/her trust if they don't know what relationships, equations, and bases you are employing in the calculations. There is no such thing as "trust me" in engineering. I have to be totally convinced and sure of any software before I put my confidence on it.

• Because of the lock out, I am unable to correct all of your spelling errors.
• When dealing with a line size, always refer to the P&ID number, not just any drawing number. The P&ID is the instrument of record in an engineering project and, as such, is the place where you find the line size and full specifications for it.
• I recommend a subroutine be used to calculate the compressibility factor, Z.
• Always specify what type of ball, plug, and gate valves you mean - reduced or full bore.
• Always state what your "standard" temperature and pressure conditions are.
• Do not use the term "nominal size" for the pipe; use the exact ID of the pipe or make a subroutine that selects the ID by stating the nominal size and schedule number.

Attached Files

•  Gas Lines Sizing.xlsx   87.49KB   617 downloads

[Sherif Morsi]

Art,

I am currently on holiday by the sea side. I went through your comments and I will answer back when I am back

Sherif

[Sherif Morsi]

Dear All,

Kindly find attached my response to Art's comments. I also included some general comments.
Also, Kindly find attached the gas sizing sheet updated and "unprotected" (Sheet 1 only).

I would like to point out that it's the first time that I do such sizing sheet and what I meant by locking it is to prevent any changes to the correlations and equations made within the excel sheet. I do believe that "trust me" engineering doesn't exist and I didn't mean so by locking it

Sorry I couldn't add the response sheet as word file cause it says "you are not permitted to upload such file" !!!

 Comment Response Sheet - Gas Line Sizing Sheet (26.04.2012).pdf   53.63KB   489 downloads
 Gas Lines Sizing - Updated.xlsx   86.35KB   614 downloads

If anyone needs it in word file, please send me your emails.

Sherif

[Art Montemayor]

Sherif:

The following are my responses (in RED) to your comments:

1. Because of the lock out, I am unable to correct all of your spelling errors.
Sheet 1 has been unlocked
I have used “Spell Check” to correct your spelling errors in Sheet 1. I recommend you do the same with the remaining sheets.

4. Always specify what type of ball, plug, and gate valves you mean - reduced or full bore.
I have used table 2.2 Page 16 (API RP 14 E - 2007) and this information is not mentioned. Could you help me get a credible reference for such values?
The API document is a “Recommended Practice”; it is not a code, standard, or a law. You can use the accurate Cv values for the indicated types of reduced and full bore valves. These values are furnished by manufacturers and can be found in their catalogs or in their information. This workbook is YOUR work product and you should do the work (when not at the beach). Perhaps some members can help by contributing their information from valve vendors.

5. Always state what your "standard" temperature and pressure conditions are.
What's the point behind stating such conditions? Where should I state them?
Are you serious? Identifying the standard conditions makes all the difference in the world. There are many so-called “standard conditions" out there and this subject has been thoroughly discussed and debated many times in the industry – especially in the recent 10 years – just ask engineering experts like Ankur, Katmar, Latexman, and many others. Do a serious research on this topic in our Forums and in other Forums and you will discover why this is such an important topic when dealing with compressible fluids.

6. Do not use the term "nominal size" for the pipe; use the exact ID of the pipe or make a subroutine that selects the ID by stating the nominal size and schedule number.
I tried to create a subroutine for this depending on the nominal pipe size and schedule no. to identify the exact ID and OD but failed. Could you help me do that? It seems it needs good knowledge of VB which I currently do not have.
Again, this workbook is YOUR work product. Why do you decide to get involved in such an interesting, challenging, and profitable project and then get lazy and lose interest? If you want to create something of value, you must invest value in it – your hard work. That is what will make it valuable – at least to you.
Since I also consider this a valuable engineering exercise for you – and ALL young engineers – I will contribute what is a classic example on what I mean by professional quality. Attached to this post is a workbook on the same topic that shows you how one engineer approached and resolved the problem. You can easily un-protect the worksheet and study and modify the algorithm(s). Note that this example does not include the valves and fittings resistances which your program does. This is a good opportunity for you to include this kind of input into your program and produce something of superior quality, convenience, and accuracy. Also note that these calculation forms should have a reference to what relationships and equations are used to generate the results.

I see that you have not followed my recommendation for a detailed explanation of the limitations to be expected in compressible flow calculations. These limitations are listed in many textbooks on Fluid Mechanics – especially in the Crane Tech Paper No. 410, which you should be referencing and using as your guide - more so than API 14E.

I hope these comments serve to help you improve your work product and that you share the ultimate results with our Forum members.

Attached Files

•  Costello\'s PIPEFLOW.XLS   123.5KB   818 downloads

[Sherif Morsi]

Dear Art,

I am trying to do my best answering the comments and trying to correct the sizing sheet. I am not against any comment as long as it's adding a value to it and your comments were valuable and I am trying to find a way to implement them.

I AM NOT AGAINST ANY OF YOUR COMMENTS AT ALL. IT'S JUST I AM TRYING TO KNOW THE REASON WHILE IMPLEMENTING THEM AND NOT ONLY IMPLEMENT THEM.

I haven't lost interest at all, I am trying to teach myself more things in excel to implement the comments to the extent that I am looking for the nearest advanced excel training course in town to apply and learn more...

Be sure I am not losing interest and I am not taking your comments lightly at all...This was of the great lessons I learnt from my former boss

Sherif

[acer_asd]

You can use VLOOKUP fuction in excel for selecting ID and OD for a particular nominal diameter.
For excel training, i dont think you need to go anywhere. You just think what you want to do and search on internet. You will difinetely find a solution. There are many forums where problems related to excel & visual basic are discussed.

[Art Montemayor]

Sherif:

You are demonstrating more eagerness and ambition to continue your self-improvement as an engineer than most of the young engineers that come to our Forums. It is gratifying for us older members to see a young engineer like you working to improve his skills and experiences by spending the time to learn how to program his own routine programs - tools that will come in handy in the future.

Don't allow yourself to feel that you've not done the "right" thing. You have done the best and proper thing - taken a positive step in the direction of forging your own tools for future use. There are many books today that specifically dedicate themselves to teaching engineers how to use Excel spreadsheets to program routine calculation tasks - such as this one. Acer_Asd is also correct in that there are probably hundreds of webpages in the internet that are dedicated to showing you how to use Excel to better program and calculate with generating documentation at the same time.

By doing this exercise now, you will have a jump-start over other competing young engineers in Egypt and elsewhere because you will have a deeper and personal knowledge of the required algorithms and you will develop a disciplined and orderly way to think out engineering problems in the future.
Keep up the good work.
(And don't fret about being against my comments. Do your work in your particular manner and preference. My comments are meant to stimulate you into forging a better product; they are never meant to convince you to use them in your work.)

[Sherif Morsi]

Thank's Art for your comments....

I just want to point out that all comments are welcome, process engineering is all about brainstorming and bringing up new ideas and concepts.

I will get back again as soon as I have some improvements, I will keep you posted of course

What about the liquid line sizing sheet? I received no comments about it at all !!!

Sherif