30 replies to this topic

[jprocess]

Dear all,
How NPSH for reciprocating pumps should be calculated?
Which diferences exist in calculation in comparison with centrifugal pumps?
Thanks in advance.
Cheers.

[JoeWong]

jprocess,
If you take some effort "google" it, i am almost certain that you will find your answer...

You may check API 14E for explaination & example.

JoeWong

[jprocess]

Dear Sir,
I checked API 14E totally but I did not find any material regarding to my concern.
Warm Regards.

[JoeWong]

jprocess,
I am referring to API 14E, 5th Edition, 1991...

Please read section 2.3, part b (page 15) for some explanation...
Please read subsequent page (page 20) for calculation of NPSHa...
Please read example A2,page 50-51 for example...

Hope above help...

JoeWong

[jprocess]

Dear Sir,
Thanks a lot for your guide.
But one question:
As you know the title of this standard is "Recommended Practice for Design and Installation of Offshore Production Platform Piping Systems"
Can I use it for onshore application of reciprocating pumps?
Warm Regards.

[JoeWong]

jprocess,
I don't think there are any differences from acceleration head / NPSH persepctive......you can confirm my statement by checking any Pump Handbook.

JoeWong

[Dtan76]

Joe/JProcess

Why make thing so difficult there? don't confused Reciprocating pump NPSH(a) calc with centrifugal pump methodology, both is the same.

Attached please find Pump sizing spreadsheets and literature. A good article explained NPSH(a) also attached here.

a) Pump sizing - Centrifugal or Reciprocating
Pump Min flow
c) Pump By pass
d) Pump NPSH(a)
e) detailed hydraulic line & pump sizing (Line sizing, pressure losses)

Regards

[jprocess]

Dtsn76:
The Npsh calculation as you claim is not the same for reciprocating and centrifugal pumps.The difference is in a term called "acceleration head" that for centrifugal pumps is negligible but for reciprocating pumps you should include it.Just look at the reference that Joe mentioned.
Good Luck

[Alawi]

Hello,

Post # 7 stated that there are some attachments, I cant find any! am I missing some thing.

Thanks

[Dtan76]

Hi

I'm not sure why they removed the download link, if you need pump calc / hydraulic line checking / pump literature just give me your email and i will sent it.

regards

[oomme]

Please, send to me at obiomac@yahoo.com.

You can also copy me at obioma.osuoha@impac-nigeria.com.

Thank you

Obioma osuoha

[wnovaes]

Please, e-mail me as well.
william.novaes@oxiteno.com.br

Thanks and Best Regards.
WSN.

Dtan76,

Please, e-mail me as well.
kebabhouse@gmail.com

Thank you.

[thuha]

Dear Dtan76,
I am an unior engineer, I am trying to set up a speadsheet to check pumps performance. Could you feel free to sent this file to me by email: ntthabh@yahoo.com.vn
Thanks & best regards

[Dtan76]

Ok

I'm sending out, check your mailbox.
Due to overwhelm response on pump spreadsheet, can you guys wait couple...
I try to upload here but internet too slow lah
also, i got 3.3 MB space only

[mosa]

Could u pl send to momsalih01@yhoo.co.in

[hamid350]

Dear Participants,
Is there any one who knows how i can link my own model developed in Fortran with PROII by using user added subroutine
If somone have any information let me know at hamid01m213@gmail.com
Regards,
Hamid

[mabu]

Dtan76,

waiting for your loading files

thanks

[Dtan76]

Hi all

due to overwhelmed responses and i have not time to sent one by one. So i created a link here and you guy and download from here.

a) Centrifugal or Reciprocating pump sizing
Hydraulic line verifications and pump optimization
c) Pump by pass
d) Pump min flow
e) NPSH
f) Pressure drop by CARF Eng

Item (f) - a quick pressure drop & hydraulic calc from CARF> I strongluy recommended you guys use it to quick estimate pipe fitting loss, pump discharge pressure required. This program is very nice and I use it for many years.

Regards Danny

Attached Files

•  OneStop_Pumps.zip   746.15KB   759 downloads
•  Pressure_Drop_Calculator_by_CARF_ENGINEERING_35.zip   513.7KB   545 downloads

[DUmesh]

JoeWong:

Hi Friend, Please send these attachments to my email id umeshdesh@yahoo.com


Regards
Umesh

[JoeWong]

Umesh,
I encourage you to take a little bit of your valuable time to read previous post whithin this subject...You may download directly from the links inside the DTAN76's post (#19)...

BTW, your action should be quick...as i notice there are some copyrighted materials...

JoeWong

[jprocess]

Dear All,
Let's return to the discussion
We found that npsha for centrifugal pumps is independent of pump type but for reciprocating pump,npsha have dependency to pump type like simplex,doupleax,triplex.etc because the acceleration head should be specified based on pump type which is specified by vendor.So what approach the designer should follow for preliminary calculation?
Thanks in advance.
Cheers.

[JoeWong]

Don't aware of any rules of thumb...

Suggest talk to your mechanical engineer and conduct preliminary selection of reciprocating pump.

Hoping other Che Jedi advise some good rules of thumb.


JoeWong

[sarahlim]

Not sure if you have found your answer, if not, please check the post title Npsha For Metering Pump by Guest_Dave_* and there is link that gvdlans reply to the post will definitely help you understand the accelleration head...
I also attached the link for your reference.
http://www.wjta.org/...2_De_Santis.pdf

[Chiko]

NPSH for recip. is not as much critical as that for centrifugal pumps.
Why do you require NPSH for reciprocating pumps?