Tubesheet blind tapped hole for pulling out bundle 3

[erkuts]

Dear Experts,

If we drill tubesheet for blind tapped hole for pulling out bundle. Should we plug with bolt this blind tapped hole.

ASME Section VIII UG-43(d) states "The distance from the inside sur-face of the vessel to the bottom of a drilled hole to be tapped shall not be less than the corrosion allowance plus
one‐fourth of the minimum required wall thickness."

and UG-43(g)states details of studs. It is unclear that can we leave this tapped hole without plugging?

Thanks,

 

[SnTMan]

Ordinary practice is to plug it.

Regards

Mike

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

 

[r6155]

See:

https://www.eng-tips.com/viewthread.cfm?qid=479055

Regards

 

[Christine74]

Drilled and tapped holes on the face of the tubesheet for the installation of bundle pulling lugs are common for removeable tube bundles that don't already have a TEMA "C" channel or a full-diameter tubesheet. Normally these are plugged with solid bull plugs or with stiff grease. Special attention should be paid if the channel face of the tubesheet has corrosion-resistant alloy cladding.

I don't see how UG-43(d) applies because it covers attaching pipe/nozzle necks to vessel walls. I also don't see how the thread linked above is relevant here as that thread is about drilled and tapped holes for collar bolts on the bolt circle of the tubesheet.


-Christine

 

[EdStainless]

In many cases putting plug in them is the only way to assure that you can use them when needed.

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P.E. Metallurgy, consulting work welcomed

 

[erkuts]

Thanks for replies.
Actually i wanted to know that how much we can drill tubesheet and after drilling and completion of pulling and putting bundle in service, do we need plug hole that we drilled for prevent decrease tubesheet strength and preventing any leak?

 

[r6155]

This is a small and light HX. There is no need for a threaded hole to pull.
Properly you can use the actual threaded hole in the top of the tubesheet.

Regards

 

[erkuts]

Contractor demands horizontal plug to pull out bundle. Tubesheets that dont have horizontal plug are need to be drilled and threaded.

 

[SnTMan]

erkuts, little bit of guess work on my part, but I'd say a couple of 1/2-13 x 3/4 deep bottom tapped holes would do the job. Do not drill thru!

Plug with a couple of plugs of suitable metallurgy. Use anti-seize.

Might be able to go smaller, 7/16 or even 3/8 depending on bundle weight and service. Consult published eyebolt data.

Regards,

Mike

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

 

[r6155]

You can push from the floating tubesheet and avoid the threaded holes in the other tubesheet.
Be practical.
Eyebolts are frequently lost.

Regards