Stress relief requirement

[Syahar1975]

Dear experts,

We have 24" RF A105 Blind Flange for the roof manhole cover. The thickness of this BF is 46 mm.

Now we need to add 14" nozzle on this manhole cover. The neck pipe is sch. 40 A53B.

There would be internal pressure 110 mmbar.

I understand this is only roof manhole cover not the shell plate and A105 is not group I,II,III,IV,V,VI material. But the tensile strength almost same like A516-60.

Also the product will not reach this roof manhole cover

Since we will have 14" penetration on this 46 mm A015 BF, do we need to perform stress relief ?

Thanks,

Syah

 

[Duwe6]

". . .this is only roof manhole cover not the shell plate. . ."

You appear to have answered the question. It is just a structural part. PWHT is almost never a 'bad' idea, and it would improve the blind flange. Why not fabricate the nozzle assembly from a piece of 25mm plate? That blind flange is rated at over 300 psi / 2MPa at 30°C! It is 'overkill' and is causing you welding problems.

 

[Syahar1975]

Thanks Duwe6.

Yes you are right 25 mm group I material should be sufficient to take care 16" roof nozzle and that pressure.