Briggs in a reinforcing pad

[Mech2325]

Does anyone have an idea what does briggs mean??
This is a std dwg of a reinforcement pad in which there is coupling coming out of a reinforcing pad and it says that this arrangement is reqd only in case of insulated vessel
At the top of there is a 1/4" npt and at bottom there is a 1/2 coupling 1/4" briggs??

What does this have to do coming out vertically outside a reinforcing pad on a vessel??

 

[mk3223]

At the top of there is a 1/4" npt and at bottom there is a 1/2 coupling 1/4" briggs??

Please clarify what is it. Or, can you share a snap shot for it?

 

[Trestala]

Briggs seems to be a thread/taper type based on a Google search.
Your standard drawing may be indicating that the vent/test hole should be protruding above the insulation. Maybe try sharing your standard drawing for clarity.

 

[SnTMan]

Maybe...

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[JStephen]

Contact whoever will do purchasing or construct the vessel, ask them what that is. If they don't know either, then change it to something else. If it's just a standard pipe thread, re-word it.

 

[Mech2325]

Thanks all

@RaymondN: Yes its a threaded pipe and on it there is a 1/4" NPT . But, my question why is there is a requirement of it with the insulated vessel. In case, if this is there to vent out the welding gases out of the insulation, then I am confused because insulation is placed after the welding is done of nozzle pad. Then, why is there a requirement of this with an insulated vessel

 

[r6155]

Leak cannot be detected in PV with thermal insulation ,
You need to install a pipe ¼ NPT extending outside of insulation with a pressure indicador ( with 3 valves) and leak can be detected and monitored at early stages from tell-tale hole.

Regards
r6155

 

[Mech2325]

@r6155: But then, should this threaded tube not be provided on the shell?? Why is this being provided on the reinforcement pad

AS per my understanding, tell tale hole is there to tell if the vessel thickness has corroded to a dangerous level.

 

[david339933]

Mech2325: The repad holes are now called "vent holes"(UG-37(g)(h)), but were once called tell-tale holes. Not the same thing as the tell tale holes for corrosion.

 

[XL83NL]

Not the same thing as the tell tale holes for corrosion.

.. or to reveal other (major weld) defects that are covered by a repad, and cant be examined or found through NDE.

 

[r6155]

Vent hole in reinforcing pad is basically to do pneumatic test (max 1 bar) to verify no leaks in the weld between nozzle and shell, prior to hydrostatic test. If possible, the inspector need to verify the test inside of PV.

Regards
r6155

 

[david339933]

There is no requirement for testing re-pads. Optional only.

 

[SnTMan]

No requirement in Div. 1, but pretty much universally applied to all pads in client PV and HX specs.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[mk3223]

Typically, the leak nozzle reinforced pad of the vessel is tested for leak after fabricated. The piece of the tube on the vent hole and extending outside the insulation is to detect any leaking possibly around the nozzle.

 

[KevinNZ]

During operation the vessel could leak at the branch weld under the pad. This will be seem as product coming out the hole in the pad. The hole also stops the space between the pad the vessel coming under pressure. Pressure could fail the pad.

 

[r6155]

UG-99 ,...... leakage is not allowed at the time of the required visual inspection.

The visual inspection of joints and connections for leaks at the test pressure divided by 1.3 may be waived,
provided:
(1 ) a suitable gas leak test is applied

Therefore pneumatic test in reinforcing pad of nozzles ( before hydrostatic test) , is not a requirement, is a benefit.

Regards
r6155