We are having U type exchanger with Shell side MOC –SA 516 Gr 70 and Tube side MOC-Titanium2
Design code is ASME Sect VIII Div.2 Ed.2013
Girth flange Bolting for shell side specified as per FEED is SA 540 B24 Cl. 1 ( size is 3")
MDMT of Tube side and Shell side is -46 °C
However, due to regret letter received from fasteners manufacturers,Vendor proposed to use SA 540 B23 Cl.1
The proposed MOC may be acceptable by designer since :
1. Due to NO change in allowable stress, design of Girth flange will not change.
2. Since these fasteners are externally coated with robust painting system before installation, slightly low % of Mo content can be taken care of.
However, main concern is the Impact Testing requirement :
1. B24 : Minimum energy values are shown in Note 3 of Table 2 of SA 540
2. B23 : Note 4 of Table 2 of SA 540 states that "No minimum values established and tests shall be run for information only".
3. How to check these values are minimum required/acceptable for -46 deg.cel ?
Considering, MDMT of exchanger as -46 deg.cel, can it be allowed use SA 540 B23 Cl.1 ?
Request your views on same.
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-welding+unsubscribe@googlegroups.com.
To post to this group, send email to materials-welding@googlegroups.com.
Visit this group at https://groups.google.com/group/materials-welding.
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/73115463-f2e5-43ff-ab0d-a6e69c2cceec%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
Comments