welding procedure

[robyengIT]

I am a consultant for steel structure, but I had a request, so I would like to understand the matter for the future, I do not want to be an "immediate" expert (apologize for tech wording not correct).
Oleodynamic installation max working pressure 300 atm (approx 300 kg/cm2). Pipe ID 280 mm OD 343 mm (that is wall thickness 31.5 mm) material S355 according to EN 10025
Girth welding : which is the best material preparation (that is butt, V, double V, etc
Welding procedure : pre-heating, controlled cooling, how many layers, etc
welding material : ???
ref. standards : ASME BPVC, etc

PS : as I said I would like to be "suggested/advised" in few main points so that I can go into thoroughly

Thanks for any help

 

[metengr]

I would not recommend a structural steel material for pipe to convey fluids. You need to use an international piping code, ASME B31.3, and review materials selection for service;

For this material and thickness, this is an equivalent to A 572 Gr 50 structural steel.

weld joint design should be double vee-groove butt weld

The remainder of the welding variables would be selected based on pipe material.

You need to qualify a welding procedure specification under ASME Section IX.

 

[kingnero]

Agreed with the above. Use P, not S steel.
Welding procedures follow according to the steel selection.

Weird that you would use EN steel with ASME codes, though.

 

[DekDee]

metengr,
Presuming that is a typo - "double Vee" as pretty hard to weld inside a pipe 280 mm ID ?

robyengIT,
You say you are a consultant for a steel structure but it is carrying product ? - what is the product ?
31.5 mm is what would be considered "serious" wall thickness on a pipe.
Recommend you speak to (or hire someone) with the required expertise to help you,
Regards,
DD

 

[robyengIT]

DekDee
It is an existing (15 years) hydraulic jack (of a press machine): because of leak problems, they want to repair or better to replace. They asked for an help : as I said, I am just collecting info to tell them where to go for final info and instructions
Thanks everybody

 

[metengr]

DekDee

Yes. Single vee.