Welding tube to plate ?

[tigler]

I have a job to do shortly which involves welding a 100MM Sched 40 pipe onto a 12MM plate and I'm not quite sure how to prep. Material is mild steel.

Would it be best to cut a hole in the plate or just butt weld to it ?
If cutting a hole should that be prepped in any way ?
How should the pipe be prepped in either case ?

The assembly will be taking a fair bit of stick so I need to determine best practice for the task.

 

[hotrodder]

Can you define 'a fair bit of stick'? That and the tools to hand would determine how i'd go about it if a fillet weld isn't going to cut it. Some options here, figures 3a and 3b. If the kit is available to cut a hole econimcally then could weld both sides i.e. pass pipe part way through plate to leave a natural prep for an outside corner and add a fillet on t'other side

 

[tigler]

It will be subjected to heavy loads , like upto around 250 KG vertically down onto the plate with some shock loading.
Equipment wise I was intending to use the stick on my TIG machine.
I can have the hole cut with a plasma cutter.
You have had the same thought as me , tube part way through and fillet welding both sides. I'm inclined to weld four gussets at 90 degrees to each other on the top though.

 

[Justme]

Thats what I did with the post hole auger I have just fettled.

The tube was about 15mm & the plate about 20mm. The hole had a 2mm clearance & the tube was passed half way through the hole. Welded inside in 3 passes & the outside in 1 all the way round & then 1" stitches between the bolt holes to leave room for the bolt heads.

For doing big high load stuff with smaller gear being able to weld both sides is needed. A big workshop welder would prob just weld one side after preparing the tube & leaving a large root gap.