in very basic terms you have your assumptions reversed:
Validation is the assurance that a product (or service) meets its user's requirements, i.e. calcs for a pressure vesel design.
Verification is the determination of a product's (or service's) conformance to original specifications, i.e...
Mfgenggear, i agree and understand the machining methods you mention, but i have performed many searches and not found a document to reference. i guess i will put it on the engineer and machine shop to answer how they can assure planarity prior to placing the equipment onto the pedestals...
mfgenggear, no place on the bottom was machined each skid weighs 16tons, so flipping the skid becomes a problem.
mikehalloran, to complicate the issue, i have 6 pedestals @ different heights (3 pairs)and piping connections that have to match up to existing piping. so leveling to such tight...
i am assuming that this is a relatively new construction.
i agree with the inspectors except for the 3rd picture of the bend. i would say that is a thermal crack.
regardless, if you did not find evidence of FOD (foreign object damage), like loose material in the bottom of the vessel, i would...
Mike,
thanks for the response. what you have described is what i have observed over the years.
my quandry is, i was looking at a skid that has some pedestals welded on it and the tops had to be machined "flat & true" to the base of the skid (within .001"). however, the drawing nor the skid...
(not for CNC programing, i have already read up of zero reference points - tool, machine & part) but to establish a beginning point in relationship to the whole part?
i am not a machinist but have seen some machining operations and heard machinists use the term witness point or reference point...
stanweld - agree & have heard the PO reasons for not doing NDE, even informational
weldtek - agree on the Minimum requirements. seems butt welds are covered more than any other type of welds for NDE & i do not seem to have the same uphill battle with Sec VIII fabricators/buyers
FYI, i did look @ B31.3 344.7 and it says "when specified in the engineering design".
may original question remains.
gtaw, your post is why i asked this question. i cannot seem to get it thru to some that a little in-process NDE is cheap compared to rejects or failures or safety
does any Code prescribe or require in-process NDE (mt, pt,ut,etc)? i have searched various Codes and cannot find any requirements. everything i see is for final inspection.
TIA
what did you specify when you purchased the shaft; any acceptance criteria, Standard to meet, your own specification?
the vendor may just be wanting to increase the price of meeting your requirements. vendor standard and customer standard are some times cause for additional measures (costs).
