Length of plate required

[Faiz vhora]

I have required diameter of shell is 500 mm
Plate having thickness of 20 mm.
Tell me the length of plate required to make required diameter & Tell me the formula to determine elongation after rolling process.

 

[david339933]

Use the diameter at mid thickness.
You don't say whether 500mm is OD or ID. If ID: 500mm + 20mm = 520mm Diameter to mid thickness. 520mm x Pi = 1633.63mm
If OD: 500mm - 20mmm = 480mm Diameter to mid thickness. 480mm x Pi = 1508mm.

 

[SnTMan]

If the seam is welded, that may require an allowance of its own.

Regards,

Mike

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

 

[r6155]

You must discount the root opening of the groove weld.

Regards

 

[david339933]

You could also take the circ of the head and subtract three times the plate thickness + 1/8". So circ of head - 63mm in this instance. This is what the old school fitters taught me many moons ago.

 

[EdStainless]

You have to account for the thickness, bend radius, material strength, and forming method.
Just remember that you never want to come up short.
This is why most shops use an empirical method.

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P.E. Metallurgy, consulting work welcomed

 

[Faiz vhora]

Thank you all so wheather i have to cut 1508 mm or lesser than that so that I don't have to cut extra material after rolling and if lesser what exact length i have to cut before rolling.
Regards

 

Oh dear, we're crowdsourcing our fabrication steps now.

Consulting the interweb instead of having trained people - what could possibly go wrong?

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[austsa]

Plate rolling process usually results in a segment of straight length (at the starting end of the plate). Your posts suggest that you've little experience in plate rolling. You should let experienced vendors to roll for you.

 

[Faiz vhora]

Yes i dont have any experience in plate rolling
I just got a project on that that's why i have some doubt in my project i have to calculate that extra length(elongation or stretching) so that we don't have to cut extra material after rolling process.Thats why i want particular formula.
Thank you all

 

[austsa]

Go to youtube and search for "W11 mechanical 3-roller symmetrical plate rolling machine". At 0:38 and 1:22 of this video, you can see short straight lengths on each end. This is normally outside of PV design roundness tolerance.

 

[david339933]

That is why you crimp the ends.....

 

[3DDave]

You can either go back to the rollers after the weld to curve the straight sections or do two pieces where they are over-long to get the 180 necessary and do two welds.

Count on having to trim after rolling and before welding. The amount of elongation depends on the amount of plastic deformation and that depends on the yield strength that can vary through the thickness of rolled material.