Insulating Welds prior to Section I Boiler Hydro

[bpv66]

Is it common practice to insulate over Section I welds prior to hydro testing a new utility boiler or HRSG?

This comes up a few times per year and I am frequently told by the Certificate Holder that "we do it all the time." Section I doesn't address leaving the welds exposed and only states the boiler shall be "closely examined" during the pressure test.

Interpretation I-89-21 permits insulating of power boilers without longitudinal welds prior to hydro testing (with agreements and extended hold time), but what if the item contains a longitudinal weld?

My opinion is that it cannot be done per the Code.

I was just wondering how often this actually takes place in the field and what Code justification is used for acceptance.

Thanks for your input.

 

[metengr]

bpv66;
In reviewing BPV I 2015 edition there is no obvious wording that requires access to a longitudinal seam weld during hydrostatic testing assuming the volumetric examination had been performed during fabrication.

With that said and your Interpretation cited, if you review Inspection and Tests in PG-90.1.13 Performing the required inspections
and witnessing hydrostatic tests (PG-99, PW-54, PB-49,PMB-21, PEB-17, PEB-18), it is an area where the AI needs to establish protocol upfront to ensure that the longitudinal seam weld can be made accessible for visual examination of leakage. This is something that needs to be planned and discussed between the AI and Certificate holder so it is understood. I don't buy the argument that we have done this before and it is common practice.

 

[chicopee]

In my opinion, all the welds should be exposed for examination during hydrostatic test; don't insulate until the hydro test is done. If insulation is already in place cut out that insulation covering the welds.

 

[bpv66]

Thanks guys. I concur.