fiber elongation

[ChiangJaron]

Dear All,

I have a question about fiber elongation calculation for the material P No.1 Gr No. 1 and 2.
And whether necessary stress relief or not after forming.

For example,
Material: SA-516-70
For pressure vessel head application : approx. 2:1 semi-elliptical
Head inside dimension : φ650 mm
Used thickness : 9 mm
Head manufacturing sequence: pressuring for sphere radius + spinning for knuckle radius.

Per UG-79 of ASME section Viii Div.1
The fiber elongation calculation for pressuring % = 75 * 9 / (650*0.9) = 1.154 %

The fiber elongation calculation for spinning % = [75 * 9 / (650*0.17) ] * [ 1 - 0.17 / 0.9 ] = 4.955%

How about the combination fiber elongation ??

 

[Don56]

No. See UCS-79(d). The fiber elongation of the dish and the knuckle are considered separately. They are not added together.

 

[SnTMan]

I agree w/ Don56, but I'd say relevant portion is definition of "Rf" per Table UG-79.1.

Regards,

Mike

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

 

[Don56]

Mike, I agree with CJ's values for RF, however the value for R[sub]o[/sub] in the KR calculation should be infinity as the head was not heat treated after dishing to set R[sub]o[/sub] to the dish radius. FE= [75 * 9 / (650*0.17) ] * 1]= 6.1%. Unless any of the issues identified in UCS-79(d) apply stress relieving is not required for P1 material.

 

[SnTMan]

Without doing the arithmetic, I'd say, yeah, sounds right.

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