SA 312 TP 304L pipe stress value

[dresserrand]

I am using the seamless pipe for nozzle having material of SA 312 TP 304L. Inthe stress table ASME 2D we have two pipe description one is seamless & welded pipe & second is seamless pipe.

For operating temp. 150 C which stress value is used, from seamless & weled pipe or seamless pipe. Both have different stress value for 150 c temperature.

Hitesh Patel

 

[SnTMan]

dresserrand, if you use the lower values, you don't have to worry about what the buyers buy.

That is my practice.

Regards,

Mike

 

[Tj01]

Hitesh,

Generally speaking,If you are using seam less pipe, than the weld efficiency factor will be 1 and hence the allowable stress value will be higher than that of welded pipe.

Here in the second case if you are using welded pipe your max allowable values will be lower.

Hence, As SnTMan said, You can use the lower max allowable value and you will be on safe side if you're not sure about the pipe type(i.e.seamless or welded)

Regards,

Tejash

 

[rneill]

I would review the notes listed for each of the lines to see what differentiates the published values and when you should be using which set.

I normally specify dual graded stainless steel materials (e.g., 304/304L) and then I use the lowest published stress values for the regular grade (e.g., 304) material.

In my experience, there is not usually a cost impact to specifying dual graded material.

 

[gr2vessels]

Hitesh,
The code gives you precise indications on how to select the correct allowable stress for your application. That's why the notes are attched to each material. Read carefully all the notes, particularly the G5 and see if you can use the higher allowable or not. Pick the lower value only if you are unable to select the correct one, but this might result in unnecessary thickness increase and additional costs because of poor engineering.
Cheers,
gr2vessels