Inspection issue

[blaqesmith]

Dear experts please suggest me solution for following issue

I am inspecting a vessel as per API 510. Vessel name plate shows that it was manufactured on british standard 5169 but its material identification is not available. In fact no other documents are available. Please tell me what i will have to do? Should i move to material testing or any other solution exist?

 

[metengr]

Why do you need this information? Are you intending to perform repairs or alter the vessel?

 

[moseley]

blaqesmith, if an Alteration/ repair is required on this vessel, you may be able to obtain documentation from the certifying body it's registerd with (i.e. National Board/ Pressure Vessel Directive). In most of the vessels I have dealt with I know there are certain documents that are required to be sent in for registration. Good luck!

 

[weldstan]

One assumes that you know the service conditions. Review operating history. Check chemistry to confirm materials. If general corrosion is expected in service, visually examine for corrosion damage. Measure wall thickness at locations appearing undamaged from corrosion. Check wall thickness required based on low strength material in BS5169 and determine remaining wall thickness. If vessel in cyclic service or stress corrosion cracking service, UT examine welds for cracking supplemented with MT or PT as applicable.

Check Manufacturer, local Jurisdiction for detailed information if (NBIC/PVD) checks are not available.

 

[Duwe6]

Without Material-of-Construction, you have two choices. And one of them stinks; assuming that the vessel was made from something 'conservative' like A36 or A283 Grade B. This is almost guaranteed to give the result that the vessel is already too thin to run at the listed MAWP.

The other [more intelligent] choice is to assume that the vessel builder was competent. So start using common steels for your calc's and find one that works with the vessel's original thickness. A good inspector will search around with the UT meter and be able to determine what the original thickness was, unless everything on this vessel experienced a uniform corrosive attack [think 100% full of acid; not very likely]. Then, using the material strength that will 'work' with the original thicknesses, evaluate your vessel and see if it is OK or requires a derate and/or repairs.