Hydrotest Pressure NBIC

[rmillercwi]

I am involved with a tube leak repair in a re-heater. Would like to hydrotest to look for other leaks but am unsure of the required pressure for in-service boilers. Original code of construction 98 section 1, 2000 addenda.

I know this repair works falls under the NBIC code. Is there a specified Hydrotest pressure? I recall hearing 80% of design. Is this correct? If so, why.

 

[metengr]

No, the NBIC does and will not specify a recommended test pressure. Review RC-2051. The test pressure is based on agreement between the AI and the Owner/User.

I will say from my own experience and suggested advice to you, the only benefit derived from a pressure test after a repair is to look for existing leaks. The pressure test will not provide any other benefit for an in-service pressure retaining item.

 

[rmillercwi]

Thanks Metengr, I couldnt agree with you more regarding the limited value of a hydrotest for a single failure. NDE will complete the repair procedure.

In this case a tube leak was found by accident while repairing something un-related. The exact reason for failure has yet to be determined with 100% certainty and they want the unit up as soon as possible. The hydro would been a nice tool to find other failures we may have missed.

Later conversations revealed other difficulties. Turns out various reheater piping supports are not sufficient to handle the piping weight if filled with water unless elaborate dunnage is designed/installed.

As always, thank you for the code tips.

 

[metengr]

rmillercwi;
Regarding looking for leaks, especially in a reheater tube circuit we normally will use air at 15-20 psig with a sonic gun or try to use vacuum and listen for obvious leaks.