11 replies to this topic

[J_Leo]

Dear Friends,

 

We are working on a project for its detailed engineering phase. Eventually, the client wants the overpressure protection system for the unit to be in iPRSM. I don't have experience with iPRSM. Generally, we size the PSVs using spreadsheets and deliver the calculation packages to the client.

 

My question: is it better to use iPRSM directly for PSV sizing without doing calculations using spreadsheets? Can this significantly save man hours? How user-friendly is this software? I am thinking we might need training from the software provider for the excise.

 

Anyone with experience with iPRISM to give some advice?

 

Thank you.

 

-Leo

[serra]

I have used the software several years ago (maybe last versions include more features),

the version I tested was based on VMG Thermo, for PSV sizing/rating I found it a bit limited for non standard and two phase cases (when compared with my preferred toolkit based on Excel + Prode Properties)

but Prism has built-in procedures to manage a large number of cases and it allows to verify compliance with many standards such as API, ASME, ISO, OSHA ... plus it stores your PSV data etc. etc.

Of course it depends from application, no idea of the cost of last versions,

probably much higher that a solution based on Excel + library but it adds many useful features.

[fallah]

Dear Friends,

 

We are working on a project for its detailed engineering phase. Eventually, the client wants the overpressure protection system for the unit to be in iPRSM. I don't have experience with iPRSM. Generally, we size the PSVs using spreadsheets and deliver the calculation packages to the client.

 

My question: is it better to use iPRSM directly for PSV sizing without doing calculations using spreadsheets? Can this significantly save man hours? How user-friendly is this software? I am thinking we might need training from the software provider for the excise.

 

Anyone with experience with iPRISM to give some advice?

 

Thank you.

 

-Leo

 

Leo,

 

As far as I know, IPRSM or Intelligent Pressure Relief System Management not only delivers the info needed to address pressure relief issues during the design of a new process but also can manage the pressure relief issues in existing systems.

 

In my opinion, it's better using IPRSM to cross check or verifying the PSV's sizing have already been done by usual engineering and design procedures. 

[Bobby Strain]

In all my working years, I only estimated the PSV size. The vendor is always responsible for correctly sizing the valve. Your job is to be sure you cover the correct scenarios and calculate the required relieving rate and properties. Anything is better than a spreadsheet. Most engineering companies follow very detailed procedures that mostly consume lots of manhours. Hence, more time is more profit.

 

Bobby

Edited by Bobby Strain, 11 December 2017 - 02:58 PM.

[J_Leo]

Serra, Fallah, and Bobby,

 

Thank you very much for sharing your experience. 

 

Do you think iPRSM is a good tool for sub-header and header sizing?

 

Regards,

-Leo

[serra]

the (old) version I tested wasn't able to solve netwoks (don't know if last version does that),
it did include Diers two phase model and other specific models (for critical/subcritical flow),
with single phase when compared with another software (Prode Properties) results are close but different for two phases (depending from model, as you know HEM approach can result conservative while other models may predict lower dP etc.),
as said in my previous post the software I tested did include many different procedures (i.e. calc's, database, selector etc.)
and all these features may influence your decision...

Edited by serra, 13 December 2017 - 03:32 AM.

[Bobby Strain]

J_Leo,

      Your company should have some policy in regard to using new software for design. If your client wants all the information in iPRSM, you should charge them. But you should design the facility with proven software or methods. I don't believe any software such as this is certified by any recognized authority. So the user must validate it in some manner.

 

Bobby

[J_Leo]

Serra and Bobby,

 

Thank you for the advice. The client is using it for other units already. If they want us to do that, we will charge them for the service. Then I will find out if it is a good tool.

 

-Leo

[Pan Nata]

Nothing special with that web-based software. Yes, that software is user friendly, more and less like using spreadsheet.

[J_Leo]

Hello Pan,

 

Thank you for your input. Can it do flare network evaluation like Aspen Flare Analyzer? Does the system work like a network? How do you set up the system for a unit in a refinery?

 

Thanks,

Leo

[AlertO]

Leo,

 

As per my latest experience with iPRSM, it still cannot be used for a full network analysis like Aspen Flare Analyser. Also there are still a number of limitations for the typical calculations such as;

1. Not all scenario that iPRSM can be used for determining the relief load. You still need to do it outside and attach them into the program.

2. PSV database is only for one or two manufacturers. So, it is not so useful if you normally use other brands of PSVs.

3. For piping input, there is no figure or element for reference which part i.e. tail pipe or sub-header of the actual piping you are considering. so it quite difficult to analyse the results.

 

i really not aim to discredit the program and of course there is many advantages to use it, just to highlight the points which you may face with the difficulty during your coming work.

[J_Leo]

AlertO,

 

Very good information. In fact, I am working with the spreadsheet outside iprsm. Later on, we may need to transfer our results into it.

 

Regards,

-Leo