Machining of Header/Pipe End plate -ASME Code 2

[Ilanseran Ramadass]

Hello Friends,

I need a clarification on below issue.

If we are providing 45mm thk end plate for an Header or pipe in fabrication drawing. But in Shop, available thickness is 50mm only.so they are machining the plate material to 45mm thick from 50mm thick plate.

Whether ASME code allows to machine the Plate materials?

Can anyone Suggest on this issue

Material used: SA 515 GR.60 /SA 516 GR.70

Regards,
R. Ilanseran

 

[XL83NL]

What design or construction code are you working to/with?

Which sections of the applicable code have you already consulted?

What led you to believe the answer isn’t in there for you to be found?

Please bear this forum is full of experienced engineers, willing to provide their (valuable) free time for members like you. In return, we’d like Tovar you have taken at least some effort in solving your question, and showing us what you have found so far that made you think this is a REALLY tough nut to crack.



Huub
- You never get what you expect, you only get what you inspect.

 

[Trestala]

Why not just use the 50mm as is and have that extra thickness?

 

[Snickster]

I agree with Trestala. You would not machine a plate to reduce the thickness unless there is some dimensional restriction why you really need 45 mm. Otherwise standard thickness plate would be used of next available thickness.

 

[SnTMan]

Generally speaking, if a thing is not prohibited it is permitted.

Regards

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[r6155]

Some drawing?

Regards

 

[MJCronin]

I agree with the comments above:

1) First, you need a piping code or standard for design. Contained within that code, will be permitted weld and joint configurations as well as weld standards as well as permitted materials. ASME B31.1 and B31.3 are commonly used. You cannot be "lazy" and adopt the third-world stance "Where in all of the rules of the world does it tell me that I CANNOT DO "X" ?

2) Second, you claim to be attaching a "plate" to a "header" with no metion of temperatures, pressures, welding or of materials used. How can anyone possibly help you ? Is this a FLAT PLATE END CLOSURE to a pipe ? .... No one can tell

3) Third, I hope that you are not slapping a quickie/cheapie fillet weld onto large diameter piping components. Piping and vessel Codes and Standards have severe restrictions on this type of weak joint

Let the long and confusing question and answer period begin !!!

MJCronin
Sr. Process Engineer

 

[Ilanseran Ramadass]

Thank you all for your valuable reply.

Hello Mr.MJCronin,

Regret for the insufficient data provided by me.

1.we are designing the Boiler Super heater Header (Code of construction is ASME SEC-I ) in which both the ends of Header is welded with End plate (Circular flat end plate)

2.Pressure - 111 Kg/cm2 , Temperature - 450 Deg Celsius, Welding type as per ASME SEC-I PG-31 (i-2), End plate Material used is SA 515 Gr.60. Header material used is SA 106 Gr.B

Please share if you have concern on this......

My Question is "Whether the Plate material can be machined to reduce the thickness? Is the Code allowing it?

Thank you

 

[MJCronin]

Soooooo...

You have a "Boiler Super heater Header" (BTW, this is part of the boiler proper) ... Where you state that your Code of construction is ASME SEC-I.... "in which both the ends of Header is welded with End plate (Circular flat end plate)

One and only one question, sir ....

"HAVE YOU PERFORMED A CALCULATION OF THE FLAT_PLATE THICKNESS AS REQUIRED BY THE ASME CODE, UNDER THE STEAM TEMPERATURE AND PRESSURE CONDITIONS THAT YOU DEFINE ? .... or did you and somebody from the welding shop, just assume that the FLAT PLATE THICKNESS WILL BE THE SAME AS THE PIPE WALL THICKNESS ?

(Pleasehave a look at UG-34; ASME VIII-1)

https://www.eng-tips.com/viewthread.cfm?qid=250655

Are you aware, sir, ... that a boiler seems to explode every single week in the third world ?

MJCronin
Sr. Process Engineer

 

[MJCronin]

https://www.cis-inspector.com/asme-code-calculation-flat-head-circular.html

MJCronin
Sr. Process Engineer