Ganfoss2
Mechanical
- Oct 23, 2007
- 32
Dear all,
in a girth flange bolted connection, to full fill the PED requirements, is it necessary to purchase bolts and nuts with the impact test included in the Material Certification.
Question: which value of minimum Impact Energy (Cv) it is correct to specify? Which is the Transition Temperature where for lower temperature the value of Cv fall down?
Ex.: SA-193 Grade B7 bolts do not foresee in its Material Specificationany minimum value of Cv nor any associated temperature. It "brother" SA-320 Grade L7 yes, but their field of application are different (one for high temperature, the other for low temperature)!
I know that SA-193/B7 is a ferristic 1Cr-0.2Mo steel and therefore (for its nature) doesn't present a "good toughness" at low temperature.
If I use the En-13445 Code as a reference (Par. B.2.2.3 & Par. 4.2.4 of En 13445-2:2002 Issue 01) it is required a MIN. 40J at the lowest aspected temperature (not the classical value of 27J like for all the other material).
Does someone have an idea regarding the Min. value of Cv to ask for in case of design with ASME VIII-1/VIII-2 Code + PED 97/23/EC + ASME Materials?
Many thanks in advance.
ANN
in a girth flange bolted connection, to full fill the PED requirements, is it necessary to purchase bolts and nuts with the impact test included in the Material Certification.
Question: which value of minimum Impact Energy (Cv) it is correct to specify? Which is the Transition Temperature where for lower temperature the value of Cv fall down?
Ex.: SA-193 Grade B7 bolts do not foresee in its Material Specificationany minimum value of Cv nor any associated temperature. It "brother" SA-320 Grade L7 yes, but their field of application are different (one for high temperature, the other for low temperature)!
I know that SA-193/B7 is a ferristic 1Cr-0.2Mo steel and therefore (for its nature) doesn't present a "good toughness" at low temperature.
If I use the En-13445 Code as a reference (Par. B.2.2.3 & Par. 4.2.4 of En 13445-2:2002 Issue 01) it is required a MIN. 40J at the lowest aspected temperature (not the classical value of 27J like for all the other material).
Does someone have an idea regarding the Min. value of Cv to ask for in case of design with ASME VIII-1/VIII-2 Code + PED 97/23/EC + ASME Materials?
Many thanks in advance.
ANN