maximum under tolerance for plate 1/2 inch 1

[stan000]

what is maximum under tolerance for plate 1/2 inch.
as per code 0.01 or 6% of 0.5 inch which is 0.03
so i am considering max under tolerance is 0.03
please let me know

stanly

 

[TGS4]

What Code? Plate bought to what spec?

 

[DSB123]

stanly3164,
You seem to be answering your own question here. If you know the plate spec (as requested by TGS4) then read it and it will tell you the thickness tolerances for the plate or will refer you to another dimensional standard which will tell you.

 

[stan000]

ASME section VIII DIV 1

 

[Don56]

If the plate is governed by SA-20 it may be 0.014" under nominal thickness and be in tolerance.

 

[david339933]

Under-tolerance per UG-16 is the smaller of .01" or 6%, so in your case is .01" not .03"

Using the specification or referenced specifications such as SA-20 for thicknesses is no good. Again see UG-16.

 

[stan000]

yes. david is right.
i was confused by maximum under-tolerance for plate.
As per UG-16 Plate material shall be ordered not more than the smaller value of 0.01 in. (0.25 mm) or 6% of the ordered thickness.
It means max. under-tolerance permitted by ASME IS 0.01 Which IS Lower than 0.03

Thanks david

Regards
stanly

 

[JohnGP]

Actually the plate specification governs the plate dimensional tolerances. Plate specifications for ASME pressure vessels are governed by SA-20 for permissible variations, and this does have a permissible under-tolerance on thickness of 0.01". UG-16 doesn't preclude larger under-tolerance, but the design must account for this - see UG-16(c), where it is stated:

If the specification to which the plate is ordered allows a greater undertolerance, the ordered thickness of the materials shall be sufficiently greater than the design thickness so that the thickness of the material furnished is not more than the smaller of 0.01 in. (0.25 mm) or 6% under the design thickness.

 

[Knife44]

Does anyone read the dang books anymore?

API510,API570,API653,API577,API571,
API580, NBIC AI. A.S. Eng, BSME

 

[JohnGP]

'fraid it's necessary if you want to be code compliant.....

 

[JStephen]

If I remember correctly, that 0.01" undertolerance is also intended to specify the significant digits of the measurement, so the measured thickness is rounded to 2 decimal places, then compared to the required thickness. That's where the 0.014 vs 0.01 comes in; they're considered the same thing for that tolerance.