2 replies to this topic

[Padmakar Katre]

Dear All Chemical Engg 'Gurus',

I have a system shown in the attatched flowsheet.Now I will describe the equipments,
E1-Shell and Tube Heat Exchanger "FTS" (TEMA Class- AXM)

Tube side inlet -Water flow of 120000 kg/hr at 30 kg/cm2g and 52 C and outlet at 62 C.
Delta P=0.07 Kg/cm2g......Design Pressure -35kg/cm2g

Shell Side inlet -Mixture of CO2 and Water (85% CO2) flow of 25000 kg/hr at 2.2 kg/cm2 and
100 C and outlet at 90 C Delta P-0.7 Kg/cm2g.......Design Press-5Kg/cm2g

Now in this case I want to know is there requirement of the PSV in shell side O/L to protect the system in the event of tube rupture of E1 as the Flash drums V1 and V2 and the air cooler E2 design pressure is not more than 5 kg/cm2g and there is no PSV but there is one valve in the Vent line at O/H of V2.If I will give this vavle a minimum opening stopper so will the system be protected in the tube rupture event. Or shall I provide PSV?

Any information apart from above is required please let me know......
Thanks In Advance.

Regards,
Padmakar Katre

Attached Files

•  API_10_BY13.xls   975.5KB   206 downloads

[pleckner]

For the future, it would have been helpful if you showed your conditions right on the drawing.

Also for the future, this type of question should be posted in the Relief Devices forum.

Assuming of course that you are located in a place that follows ASME or equivalent, you will need a PSV if the design pressure of any vessel in this system exceeds 15 psig (1.05 kg/cm2g if my conversion is correct) AND you are able to operate the equipment above 1.05 kg/cm2g at anytime. Your design and operating pressures indicate that the shell of E-1 is an ASME Code vessel and therefore you need a PSV on it or anywhere in the system that can protect it. I can't anything about the other vessels based solely on the information you provied but I supect they too will be pressure vessels.

As far as scenarios for PSV sizing go, this is totally up to the process engineer (you?) to determine. I can say that based on the design conditions you give on E-1, then yes, a tube rupture scenario is credible. If it is not already too late, I strongly suggest you design the shell and tube at the same conditions at best or use the 10/13 ratio. This way you can eliminate tube rupture from the list of credible scenarios.

By the way, if all the equipment in the system that would be protected by this PSV is stress tested at 1.5 x design pressure and not 1.3, then you can use the 2/3 rule to set the shell & tube design pressure and still eliminate tube rupture from the list of credible scenarios.

[JoeWong]

Phil,
Suggest to move this post to Relief Devices forum.

Padmakar,
Do a simple search in the Relief Devices forum by special keyword "tube rupture", you may find a lot of discussion on similar topic.

Try this...
http://www.cheresour.....+tube rupture

JoeWong