Two different thickness Two different Materials (x65 - x70)

[Cesar Almada]

Good night friends

My friend to other department doesn’t buy a Flange because I don’t know why, but now we have a problem because we need to weld a spool Saturday and we have only the next materials:

We have a 6 inches pipe with a thickness of 0.250'' and it’s API 5L X70, and he doesn’t buy a flange to weld with that pipe, but we have in stock a 6 inches flange with a thickness of 0.432 and X65. is it possible to make a counter bevel and leave it up to 0.250'' which would be almost double or what can we do with that ?

And it’s possible to weld X65 with X70?

Can we do these actions?

Thanks for helping us.

Oh and if you know with what code is possible ASME B 31.8 ?

 

[LittleInch]

Yes ut's possible to do what you suggest.

The issues you face are:

Your design pressure is now a little reduced to whatever it would be for 0.25" x65 pipe.

You need to machine a bevel at an angle of min 1:4 assuming this pipe is piggable.

You need to check if your existing welding procedures allow this change of material or if you need to qualify a new welding procedure.

Buy the right flange.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Cesar Almada]

@LittleInch Thank you, but in a point you say: My design pressure is now a little reduced.

But no, because my thickness 0.250'' is for material X70 and my thickness 0.432'' is for X65 so I'm okay with 0.250 and for 0.432'' I'm okay too because is a bigger thickness than 0.250''.

I think that

 

[LittleInch]

Yes, but you are going to machine the x65 flange down to 0.25"...

That means you calculate the pressure based on 0.25"of x65.

That's how it works.


Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

That could be how it doesn't work.

 

[Cesar Almada]

@LittleInch Ohh yeah yeah, I got it. Yes i did the calculation and still if i reduce my thickness to 0.250'' I meet all parameters. This because i got a location class as 2.

@1503-44 I didn't understand your comment.

 

[1503-44]

Depended on the area class and pressure. You're ok then I guess.