Impact test temp for P-4 flange material

[jtseng123]

Dea all,
A simple question but only hit once a while:

For MDMT =-50F and P-4 material construction, per UCS-66(b)(1)(b), is it correct that I just need to make sure the ratio of (MAWP)/(flange pressure rating at room temp) =0.7, so I can take 30 F reduction from Fig UCS-66.1, to impact test the flange at -20F, but stamp it for -50F ?

 

[metengr]

Yes, see below, excerpt from ASME Section VIII, Div 1 for flanges

(b) Figure UCS-66.1 may also be used for components
not stressed in general primary membrane tensile
stress, such as flat heads, covers, tubesheets, and flanges
(including bolts and nuts). The MDMT of these components
without impact testing as determined in UCS-66(a)
or (c) may be reduced as determined from Fig. UCS-66.2.
The ratio used in Step 3 of Fig. UCS-66.2 shall be the
ratio of maximum design pressure at the MDMT to the
maximum allowable pressure (MAP) of the component at
the MDMT. If the resulting temperature is colder than
the required MDMT, impact testing of the material is not
required, provided the MDMT is not colder than −55°F
(−48°C).

 

[jtseng123]

metengr, thanks for confirmation.