Dear Group,
Is there not a better way of receiving these digest mails. It is a jumble of questions repeated upteen number of times with everybody's answers. Can somebody devise a report format that will condense it into neat text excluding all those unwanted email trails.
Sajit Viswan
Parsons
Kuwait
----- Original Message -----
From: <PipingDesign@yahoogroups.com>
To: <PipingDesign@yahoogroups.com>
Sent: Tuesday, September 17, 2002 10:19 PM
Subject: [PipingDesign] Digest Number 650
Texas Flange - a good source for information on industrial flanges, all they
ask is for referrals for designs they help with.
877-610-8924.
www.texasflange.com
There are 13 messages in this issue.
Topics in this digest:
Message: 1
Date: Mon, 16 Sep 2002 15:10:25 +0100 From: "James, Barbara" <bjames@mitsuibabcock.com> Subject: RE: Recommended maximum flow velocity
Samuel
Thank you for your reply. The concern with the CO2 line is erosion rather than pressure losses.
I am somewhat confused by your formula, the units appear to be SQRT(m^3/kg) which I can't reconcile with a velocity (m/sec). Is there any more to this equation? If you have a reference for it, would you be kind enough to post details?
Thanks again for your help, and sorry to appear to be nit picking, but my client will want to see some sort of basis.
Regards
Barbara
> -----Original Message-----
> From: Samuel Liu [mailto:samuel.liu@amec.com]
> Sent: 16 September 2002 14:38
> To: 'PipingDesign@yahoogroups.com'
> Subject: RE: [PipingDesign] Recommended maximum flow velocity
>
>
>
> For general engineering process design, there is almost no
> fixed limitation
> on velocity value. That will vary from different system
> design, i.e., on the
> allowable delta P. For gas pipeline, the velocity should be
> always less than
> the erosional velocity which is 122/Sqrt(density) in SI unit system.
>
> Regards,
>
> Samuel Liu
>
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Message: 2
Date: Mon, 16 Sep 2002 09:20:25 -0500 From: "Bruce Bullough" <bbullough@sebesta.com> Subject: RE: Recommended maximum flow velocity
If you get no other response, I suggest turning to Crane (Technical paper 410, Flow of Fluids). Pages 3-16 and 3-17 have a nomograph for velocities of compressible fluids in pipe.
... Bruce D. Bullough ...
Sebesta Blomberg & Associates
2381 Rosegate
Roseville, MN 55113
651-634-7344 (office)
651-634-7400 (FAX)
www.sebesta.com
-----Original Message-----
From: James, Barbara [mailto:bjames@mitsuibabcock.com]
Sent: Monday, September 16, 2002 3:35 AM
To: 'PipingDesign@yahoogroups.com'
Subject: [PipingDesign] Recommended maximum flow velocity
Good morning all
Many thanks to those who gave me advice on finding the dimensions of reducers, I had to resort to measuring them in the end. The B and C indices in ASME NB are quite sensitive to the cone angle so it was a worthwhile exercise
Now, that I have finished the mechanical design, the client has decided to revisit the process design! There is some debate on what the maximum flow velocity should be, does anybody here know anywhere that I can find recommended maximum flow velocities? The fluid is CO2 at 250°C and 29barg.
Thanks
Barbara
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Texas Flange - a good source for information on industrial flanges, all they
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877-610-8924.
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Message: 3
Date: Mon, 16 Sep 2002 07:19:40 -0700 From: Samuel Liu <samuel.liu@amec.com> Subject: RE: Recommended maximum flow velocity
Barbara:
I don't know which industrial field you are at now. For example, if you are in the field of offshore, please refer to API RP14E.
Regards,
Samuel
-----Original Message-----
From: James, Barbara [mailto:bjames@mitsuibabcock.com]
Sent: Monday, September 16, 2002 8:10 AM
To: 'PipingDesign@yahoogroups.com'
Subject: RE: [PipingDesign] Recommended maximum flow velocity
Samuel
Thank you for your reply. The concern with the CO2 line is erosion rather than pressure losses.
I am somewhat confused by your formula, the units appear to be SQRT(m^3/kg) which I can't reconcile with a velocity (m/sec). Is there any more to this equation? If you have a reference for it, would you be kind enough to post details?
Thanks again for your help, and sorry to appear to be nit picking, but my client will want to see some sort of basis.
Regards
Barbara
> -----Original Message-----
> From: Samuel Liu [mailto:samuel.liu@amec.com]
> Sent: 16 September 2002 14:38
> To: 'PipingDesign@yahoogroups.com'
> Subject: RE: [PipingDesign] Recommended maximum flow velocity
>
>
>
> For general engineering process design, there is almost no
> fixed limitation
> on velocity value. That will vary from different system
> design, i.e., on the
> allowable delta P. For gas pipeline, the velocity should be
> always less than
> the erosional velocity which is 122/Sqrt(density) in SI unit system.
>
> Regards,
>
> Samuel Liu
>
If you have received this E-Mail in error please return it to the
sender.
We should be grateful if you would also copy the communication to
postmaster@mitsuibabcock.com then delete the E-Mail and destroy any
copies of it.
It is your responsibility to scan any attachments for viruses.
For further information, visit us at WWW.MITSUIBABCOCK.COM
Texas Flange - a good source for information on industrial flanges, all they
ask is for referrals for designs they help with.
877-610-8924.
www.texasflange.com
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
The information contained in this e-mail is intended only for the individual
or entity
to whom it is addressed. Its contents (including any attachments) are
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Message: 4
Date: Mon, 16 Sep 2002 15:36:34 +0100 From: "James, Barbara" <bjames@mitsuibabcock.com> Subject: RE: Recommended maximum flow velocity
Samuel
Thanks for the reference, the field I am working in is the nuclear industry. I can't find anything in ASME III NB regarding flow velocities. I'm not sure if it will be anywhere in ASME III and I don't recollect seeing it in B31.1 or B31.3, but I am ready to be corrected.
Regards
Barbara
> -----Original Message-----
> From: Samuel Liu [mailto:samuel.liu@amec.com]
> Sent: 16 September 2002 15:20
> To: 'PipingDesign@yahoogroups.com'
> Subject: RE: [PipingDesign] Recommended maximum flow velocity
>
>
>
> Barbara:
>
> I don't know which industrial field you are at now. For
> example, if you are
> in the field of offshore, please refer to API RP14E.
>
> Regards,
>
> Samuel
>
> -----Original Message-----
> From: James, Barbara [mailto:bjames@mitsuibabcock.com]
> Sent: Monday, September 16, 2002 8:10 AM
> To: 'PipingDesign@yahoogroups.com'
> Subject: RE: [PipingDesign] Recommended maximum flow velocity
>
>
> Samuel
>
> Thank you for your reply. The concern with the CO2 line is erosion
> rather than pressure losses.
>
> I am somewhat confused by your formula, the units appear to be
> SQRT(m^3/kg) which I can't reconcile with a velocity (m/sec).
> Is there
> any more to this equation? If you have a reference for it,
> would you be
> kind enough to post details?
>
> Thanks again for your help, and sorry to appear to be nit picking, but
> my client will want to see some sort of basis.
>
> Regards
>
> Barbara
>
> > -----Original Message-----
> > From: Samuel Liu [mailto:samuel.liu@amec.com]
> > Sent: 16 September 2002 14:38
> > To: 'PipingDesign@yahoogroups.com'
> > Subject: RE: [PipingDesign] Recommended maximum flow velocity
> >
> >
> >
> > For general engineering process design, there is almost no
> > fixed limitation
> > on velocity value. That will vary from different system
> > design, i.e., on the
> > allowable delta P. For gas pipeline, the velocity should be
> > always less than
> > the erosional velocity which is 122/Sqrt(density) in SI unit system.
> >
> > Regards,
> >
> > Samuel Liu
> >
>
>
>
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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>
>
>
> Texas Flange - a good source for information on industrial
> flanges, all they
> ask is for referrals for designs they help with.
> 877-610-8924.
> www.texasflange.com
> =====================================================
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The information contained in this e-mail is intended only for the
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they ask is for referrals for designs they help with.
877-610-8924.
www.texasflange.com
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If you have received this E-Mail in error please return it to the
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Message: 5
Date: Mon, 16 Sep 2002 15:44:23 +0100 From: "James, Barbara" <bjames@mitsuibabcock.com> Subject: RE: Recommended maximum flow velocity
Bruce
Thanks for finding the pages in Crane, I have checked our calculated velocities against the table of reasonable velocities for flow of steam on page 3-16, under most operating conditions the velocities fall into the recommended range. I hope that will be sufficient to satisfy the client...
Regards
Barbara
> -----Original Message-----
> From: Bruce Bullough [mailto:bbullough@sebesta.com]
> Sent: 16 September 2002 15:20
> To: PipingDesign@yahoogroups.com
> Subject: RE: [PipingDesign] Recommended maximum flow velocity
>
>
> If you get no other response, I suggest turning to Crane
> (Technical paper 410, Flow of Fluids). Pages 3-16 and 3-17
> have a nomograph for velocities of compressible fluids in pipe.
>
> ... Bruce D. Bullough ...
> Sebesta Blomberg & Associates
> 2381 Rosegate
> Roseville, MN 55113
> 651-634-7344 (office)
> 651-634-7400 (FAX)
> www.sebesta.com
>
>
> -----Original Message-----
> From: James, Barbara [mailto:bjames@mitsuibabcock.com]
> Sent: Monday, September 16, 2002 3:35 AM
> To: 'PipingDesign@yahoogroups.com'
> Subject: [PipingDesign] Recommended maximum flow velocity
>
>
> Good morning all
>
> Many thanks to those who gave me advice on finding the dimensions of
> reducers, I had to resort to measuring them in the end. The B and C
> indices in ASME NB are quite sensitive to the cone angle so it was a
> worthwhile exercise
>
> Now, that I have finished the mechanical design, the client
> has decided
> to revisit the process design! There is some debate on what
> the maximum
> flow velocity should be, does anybody here know anywhere that
> I can find
> recommended maximum flow velocities? The fluid is CO2 at 250°C and
> 29barg.
>
> Thanks
>
> Barbara
>
>
>
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> - - - - -
> -
> IMPORTANT NOTICE
>
> This E-Mail and any files transmitted with it, are
> confidential and for
> the
> exclusive use of the intended recipient(s).
> If you are not the intended recipient(s) please note that any form
> of distribution, copying or use of this communication or the
> information in it, is strictly prohibited and may be unlawful.
>
> If you have received this E-Mail in error please return it to the
> sender.
> We should be grateful if you would also copy the communication to
> postmaster@mitsuibabcock.com then delete the E-Mail and destroy any
> copies of it.
>
> It is your responsibility to scan any attachments for viruses.
>
> For further information, visit us at WWW.MITSUIBABCOCK.COM
>
>
>
> Texas Flange - a good source for information on industrial
> flanges, all they ask is for referrals for designs they help with.
> 877-610-8924.
> www.texasflange.com
> =====================================================
> unsubscribe: PipingDesign-unsubscribe@yahoogroups.com
>
> Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
Texas Flange - a good source for information on industrial flanges, all
they ask is for referrals for designs they help with.
877-610-8924.
www.texasflange.com
Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
If you have received this E-Mail in error please return it to the
sender.
We should be grateful if you would also copy the communication to
postmaster@mitsuibabcock.com then delete the E-Mail and destroy any
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It is your responsibility to scan any attachments for viruses.
For further information, visit us at WWW.MITSUIBABCOCK.COM
Message: 6
Date: Tue, 17 Sep 2002 08:26:28 +0530
From: Sachin_Bapat@ril.com
Subject: RE: EXPANSION STRESS RANGE
Piping code B31.3 gives value of expansion stress range as follows
Sa=f((1.25(Sc +Sh) - Sl)
where Sc ,Sh, Sl,f have their usal meaning as defined in code.
My query is
Message: 7
Date: Tue, 17 Sep 2002 08:28:00 +0530
From: Sachin_Bapat@ril.com
Subject: RE: CREEP ANALYSIS
Can anybody suggest some of softwares which deals with creep analysis.
Regards
Sachin Bapat
Message: 8
Date: Tue, 17 Sep 2002 13:20:15 +1000 From: Conor Walshe <conor.walshe@alceng.com> Subject: RE: EXPANSION STRESS RANGE
If I can remember or interpret correctly... here you go
for expansion
Sa = f(1.25Sc + 0.25 Sh)......................1 which is the original of Sa=f((1.25(Sc +Sh) - Sl) ................2
i.e. add Sh - Sl to 0.25 Sh
So here it is:
The higest value for Sa is when Sh is it's greatest allowable, i.e. = Sc
Therefore
Sa = f(1.25Sc + 0.25 Sc) = f(1.5Sc)
max f = 1.0
Max Sa = 1.5Sc whcih is equal to the Specified minimum Yield strength
i.e. Sc is taken as 2/3 of Specified minimum Yield strength or a fraction of the Specified minimum Tensile strength
So basically the formula is designed to never produce a figure above the Specified minimum Yield strength of the material and takes into consideration the effects on the allowables due to temperature.
Now, this is just my interpretation
-----Original Message-----
From: Sachin_Bapat@ril.com [mailto:Sachin_Bapat@ril.com]
Sent: Tuesday, 17 September 2002 12:56
To: PipingDesign@yahoogroups.com
Subject: RE: [PipingDesign] EXPANSION STRESS RANGE
Importance: High
Piping code B31.3 gives value of expansion stress range as follows
Sa=f((1.25(Sc +Sh) - Sl)
where Sc ,Sh, Sl,f have their usal meaning as defined in code.
My query is
Texas Flange - a good source for information on industrial flanges, all they
ask is for referrals for designs they help with.
877-610-8924.
www.texasflange.com
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
"The information contained in this email and any files transmitted with
it are confidential and intended solely for the use of the individual
or entity to whom they are addressed. If you have received this email
in error please promptly notify the sender by reply email and then
delete the email and destroy any printed copy. Additionally, if you
have received this email in error, you must not disclose or use this
information in any way."
Alcan Engineering Pty Limited.
Phone: +61 7 3218 3555 Fax : +61 7 3236 0155 Email: info@alceng.com Web : http://www.alceng.com ________________________________________________________________________ ________________________________________________________________________
Message: 9
Date: Mon, 16 Sep 2002 20:27:22 -0700 (PDT) From: Geoff Stone DD&D Australia <blenrayaust@yahoo.co.uk> Subject: RE: EXPANSION STRESS RANGE
The figure of 1.25 was decided upon in a hot and steamy meeting in NEw York when the committee were preparing ANSI B31.1/31.3. If I recall the likes of Spiel Vogel and other eminent engineers of their time were present.
Like all standards committees there are personal views and compromises.
There is a paper describing the goings on at the meeting but it is many
years
since I have read the same.
The upshot is that it was selected based upon the experience of the
engineers
who gave their time voluntarily for the good of all.
--- Sachin_Bapat@ril.com wrote:
<HR>
<html><body>
<tt>
<BR>
Piping code B31.3 gives value of expansion stress range as follows<BR>
&nbs
p;
Sa=f((1.25(Sc +Sh) - Sl)<BR>
where Sc ,Sh, Sl,f have their usal meaning as defined in code.<BR>
My query is<BR>
How the code has decided upon this value of 1.25 ? What is the physical<BR>
significance of this value?<BR>
Views are invited from team members on the subject matter.<BR>
Regards<BR>
Sachin Bapat<BR>
<BR> <BR> </tt>
<br>
<tt>
Texas Flange - a good source for information on industrial flanges, all they
ask is for referrals for designs they help with.<BR>
877-610-8924.<BR>
www.texasflange.com<BR>
=====================================================<BR>unsubscribe: PipingDesign-unsubscribe@yahoogroups.com</tt> <br>
<br>
<tt>Your use of Yahoo! Groups is subject to the <a
href="http://docs.yahoo.com/info/terms/">Yahoo! Terms of Service</a>.</tt>
</br>
</body></html>
Message: 10
Date: Tue, 17 Sep 2002 08:50:00 +0530
From: trajyagu@ltcis.ltindia.com
Subject: RE: EXPANSION STRESS RANGE
Cold Allowable Stress (Sc) = 2 / 3 x Sy(cold), Hence, Syield(cold) = 3 /
2 x Sc
Similarly, Syield(Hot) = 3 / 2 x Sh
Allowable stress = Syield(cold) + Syield(Hot) = 1.5 ( Sc + Sh ) Code seems to have divided above value with Factor of safety to arrive at 1.25 value instead of 1.5 in above equation.
Tushar.
Sachin_Bapat@ril.com on 09/17/2002 09:26:28 AM
Please respond to PipingDesign@yahoogroups.com
To: PipingDesign@yahoogroups.com
cc: (bcc: TUSHAR K RAJYAGURU/L&T-CHIYODA)
Subject: RE: [PipingDesign] EXPANSION STRESS RANGE
Piping code B31.3 gives value of expansion stress range as follows
Sa=f((1.25(Sc +Sh) - Sl)
where Sc ,Sh, Sl,f have their usal meaning as defined in code.
My query is
Texas Flange - a good source for information on industrial flanges, all
they ask is for referrals for designs they help with.
877-610-8924.
www.texasflange.com
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Message: 11
Date: Tue, 17 Sep 2002 16:07:10 +0400 From: Ahmed Vawda <avawda@aksugar.co.ae> Subject: Sea Water Suction Pipe
Dear Forum Members
My sea water pumps are cavitating!
Flow rate 2750 m3/hr each.
Delivery pressure 1.8 barg
Suction pipe 500 mm.
Pump inlet nozzle 400 mm.
There is a lot of turbulence in the suction pit of each pump. The 500 mm
suction consists of a long radius bend.
Is there some thing I can modify in the suction to reduce the turbulence?
Ahmed Vawda
Process Engineer
Al Khaleej Sugar - Dubai
[Non-text portions of this message have been removed]
Message: 12
Date: Tue, 17 Sep 2002 08:37:12 -0400 From: "Ed Engalan" <edengalan@hblpipe.com> Subject: RE: Sea Water Suction Pipe
A few items comes to mind (Pardon my weakness for the metric system):
1.) Recommended pump suction is 2.5 to 5.0 ft/sec.
2.) Pump suction reducer connection to suction piping shall be eccentric with flat side on top.
3.) Calculate your System Net Positive Suction Head (NPSHa) i.e. length of
suction piping,
vapor pressure of fluid at pumping temperature, suction lift, etc. and
compare it to your Pump Net Positive Suction Head Required (NPSHr) : NPSHa >
NPSHr.
4.) Visually check your suction line, in the USA we have known problems from Zebra Mussels.
-----Original Message-----
From: Ahmed Vawda [mailto:avawda@aksugar.co.ae]
Sent: Tuesday, September 17, 2002 8:07 AM
To: PipingDesign@yahoogroups.com
Subject: [PipingDesign] Sea Water Suction Pipe
Dear Forum Members
My sea water pumps are cavitating!
Flow rate 2750 m3/hr each.
Delivery pressure 1.8 barg
Suction pipe 500 mm.
Pump inlet nozzle 400 mm.
There is a lot of turbulence in the suction pit of each pump. The 500 mm
suction consists of a long radius bend.
Is there some thing I can modify in the suction to reduce the turbulence?
Ahmed Vawda
Process Engineer
Al Khaleej Sugar - Dubai
[Non-text portions of this message have been removed]
Texas Flange - a good source for information on industrial flanges, all they
ask is for referrals for designs they help with.
877-610-8924.
www.texasflange.com
Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Message: 13
Date: Tue, 17 Sep 2002 06:09:24 -0700 (PDT) From: constant george <chris_geocon@yahoo.com> Subject: Re: Sea Water Suction Pipe
What gives you the turbulence in the pit? Since when
do you have that turbulence? What is the depth of the
suction pipe inside the pit? Did you have the
cavitation phenomena from the very beginninig? There
are some questions that you have to check in the first
instance. After that you can go to
www.cheresources.com and there you will find some
articles marked as "Understanding cavitation". If you
don't, let me know. Of course, you should try to
contact the pumps manufacturer, who supposedly can
help you out more effective than anybody else.
Regards,
George
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