First off, if the coils contain pressure retaining welds, a hydrostatic test must be performed and witnessed by the AI - look at Inspector duties, PG-90.1.13, look at PG-112.2.4, and the P-4 Form. Hydrostatic testing can be done in the shop or in the field - see PW-54.1.
If the item contains no pressure retaining welds, see PG-106.8.1.
If the final hydrotest is to be performed in the field after assembly, witnessing by the AI is required during performance of the final hydrotest. The coil manufacturer need not have the AI present during its shop hydrotest, which is often done simply to assure leak tightness prior to shipping.
Is the Coil a replacement PART or going to a field assembly? PARTs do not necessarily even have to be hydro tested (PG-106.8) in the shop prior to shipping. Most fabricators will want to hydro test before shipping (if possible) so as not to be "back charged" for any Repairs that might have to be done once the PART is in the field. Since a PART doesn't even necessarily have to be hydro tested in the shop, therefore, the A.I. might not even witness the hydro in the shop (and this should be noted on the P-4 form). The shop hydro was basically for "information only" not Code credit.
Once the PART is installed in the field, the PART will be hydro tested and that hydro will have to be witnessed by the Inspector signing the Final Data Report (or R-1 form in case of a field Repair).
PG-106.8 Stamping and Marking of Parts.
PG-106.8.1 When only a part of the boiler is
supplied and the data are recorded on Form P-4,
Manufacturer’s Partial Data Report (see PG-112.2.4), the
part shall be stamped with
(a) Certification Mark above the word “part”
(b) certified by (name of Manufacturer)
(c) Manufacturer’s serial number of the part
(d) year built
Parts may be stamped with the Certification Mark
without being pressure tested prior to shipment
Don't confuse a code required Hydrostatic test with pressure test under the NBIC. If the ASME Section I PART contains pressure retaining welds it MUST be subjected to a Code Hydrostatic test at 1.5X MAWP to be compliant with ASME Section I fabrication requirements. If the PART has no pressure retaining welds, no code Hydrostatic test is required.
Once the ASME Section I PART is installed, it falls under the NBIC and only the connecting welds are subject to NDT/pressure testing based on current rules in the NBIC. The pressure retaining welds fabricated under ASME Section I with no code-Hydrostatic test is where problems have been happening in the field. Owner/Users did not specify a code Hydrostatic test during fabrication of the PART.
Yes, I can see that, because then the completed boiler/PV must be fully hydrostatically tested in the field and many of the pressure retaining welds may or may not even be accessible after installation.
However, I believe the Code must allow for this option, as many PARTs (with pressure retaining welds) can't be hydro tested till they are installed. A head manufacturer might have to make a large head by 2 pc construction and Code stamp the head as a PART, but he cannot hydro test just a single head in the shop, so the Code must allow for PARTs to be made without necessarily performing the final hydro test prior to shipment. Since this option is possible, I think you are exactly correct when stating the Owner/User or even R stamp holder purchasing the PART needs to specify the Code hydro test be performed in the shop.
The NBIC will be addressing this vary issue where hydrostatic testing of certain ASME section I past cannot be done. In this case, we will look at volumetric examination and perhaps a test at Operating pressure. We will see.
That is good to know, it does need to be addressed.
I wonder if ASME Sect. I might ever look at an appendix or Code Case for "Multiple Duplicates" as Sect. VIII-1 has (App. 35?). If a shop is producing 100 superheater elements and wants to continue to perform hydrostatic testing on 2nd or 3rd shift, could there be some sort of allowance that the A.I. only has to witness those performed during his 8 hour (1st) shift? He might see most all fabrication of these Parts during his normal 8 hour shift, but just miss the final hydro test if they are done on a 2nd or 3rd shift.
Section VIII-1 App. 35 allows complete vessels to be fabricated and stamped on 2nd shift after AI has worked his normal 1st shift. In the case of the Sect. I multiple duplicate PARTS (superheater elements, economizer elements, etc) they are not fabricated and completed in a single shift, so the AI does see them during fabrication. It just seems there should be some sort of way to allow qualified individual (QC) to witness any hydro tests of such multiple duplicate Parts on 2nd shift. Such items are usually exempt from stamping as well, so no stamping to witness (just verifying markings or tags).
I think such a classification (Multiple Duplicate Parts as described) would be beneficial to the stamp holder and the AIA. If AIA has to sell/provide coverage for 2nd or 3rd shift...what do they do with that manpower when no such work is going on on the 2nd or 3rd shifts?
Thanks for all the responses, I think I understand the process now. I have seen replacement boiler coils sent out with no AI witness, but the P-4 states "hydrotest witnessed by XXXXXXXX (certificate holder's) authorized personnel only, so I guess in the field they must hydrotest it as part of a repair to an existing boiler.
Yes, it must be an AI to verify the Hydrostatic test met ASME Code requirements (not NBIC pressure testing requirements for connecting welds) OR the regulatory body can grant a waiver to accept the part without a code required Hydrotest.
