Inspection Frequency of HP Loop of Urea plant

[starfarooq]

We are operating a Urea plant built on Stamicarbon technology. The High pressure synthesis loop (consisting of Reactor and stripper and HP Carbamate condensers) is made of Safurex material. We had inspected it with Stamicarbon experts in 2011 and they advised to keep the next inspection after 6 years period (2017). However our operation engineers are now insisting that we should not wait until 2017 and inspect it in 2015 shutdown.
Has somebody any idea about the inspection frequency of HP Urea equipment.

 

[dbill74]

Not an expert in Urea plants, but the engineer in me tells me that the more often you can inspect a system for problems the better. 6 years may be an industry standard or Stamicarbon's recommendation. If the 2015 shutdown is already scheduled, I don't see the harm in inspecting your HP loop. Money and time permitting of course. -Just my 2 cents worth.

 

[MintJulep]

It's a waste of time and money.

Unless something fails after the shut-down and before the 2017 inspection and your name is on the decision to not do an inspection during the shut-down.

Then it's your ass.

Which is more valuable to you?

 

[Duwe6]

Do the inspx in 2015 -- as of today, you do not KNOW what a reasonable frequency is. If you find problems, then your frequency is 4-years [or less]. If everything is OK in 2015, do it again in 2017. It takes experience in your actual service conditions to set inspx intervals. Like MintJulep alludes to, it is a tough call without a bunch of run-time experience.

 

[insproh]

The Saufrex material generally has a good life and the corrosion rate is very low. You might want to check the previous history of the HP loop and the corrosion rate pertained to these equipments before making the call inspection frequency.
If you had it inspected by Stamicarbon inspection team before and they can provide you these details it should be a good start.
The general industrial practice is to inspect in 3~4 years. Deciding factor will always be the corrosion rate and previous inspection history.