ASME B31.3 304.1.2(b) What to do!? 2

[Raaden]

What do I do if the thickness i higher than D/6? The design code doesn't specify any equations for that, only that special considerations needs to be made.
I'm more used to B31.1 and that code doesn't have any restrictions like this one(that I know of)

Thanks

Pontus

 

[prex]

You might adopt (or at least check for usability) the High Pressure Piping section of B31.3.
Note that the thickness calculated with formulae for high t/D ratii are normally lower than those obtained with the commonest formulae for low pressures: hence, only as far as the calculated thickness is concerned, you might use the thickness resulting from 304.1.2(a)

prex

http://www.xcalcs.com

Online tools for structural design

See

http://www.xcalcs.com/docs/symbolinfo.htm

if you want to use symbols on these fora

 

[bvi]

Use equation 3a. It should be fine. Note, however, that the value of Y changes. See definition of Y, in which a formula is given. Equation 3a gets progressively more conservative in heavy wall piping. You cannot design a pipe with equation 3a if the design pressure gets as high as the allowable stress. The high pressure piping rules in Chapter IX would permit thinner wall pipe than equation 3a (which a host of additional requirements).

 

[MIKEWILSON2004]

Hello,

In all other standards it is specifically made clear the difference between thick walled and thin wall cylinder calculations. I am unclear to as what determines what section to use of B31.3 as the equations for wal thickness seam to be associated with high and low pressure and not determined by wall thickness.

Many Thanks.