Hello A.H.Faraji!
Is there any particular reason why the support was to be welded on to the pipe? The reason I ask this question is because, as Giavonni stated, It's a bad engineering practice to do so!!!
The only advice I have for you is to PWHT that support, and if possible, DO NOT repeat the same engineering practice on any of the other supports!!! G. S. Crisi has spoken the word on pipe supports so, It's best for you to adhere to his advice!!!
I apologize for being so blunt but, I strongly feel that it's necessary in this case!!!
Respectfully,
SSBN727 Run Silent... Run Deep!!!