This may not be the appropriate forum, but does anyone have any information on the flange pressure/temperature revisions in the 2003 version of B16.5? I have been told by some equipment suppliers that the values have changed.
Thanks for any information.

DK,

I don't have a complete list of changes but there have been some adjustments, both up and down. Many are in the higher temperature ranges of alloys and stainless.

Beware if you have valves meeting ASME B16.34. B16.34 is normally issued about the same time as B16.5 with ratings that match but the new edition of B16.34 has not been issued yet, 1998 is the latest. Be careful if you are pushing the limits, your flanges and valves will have different ratings for those materials that have changed.

Hopefully this will be cleared with the next issue of ASME B16.34.

Kevin:
Thanks for the response. In correspondence with the Coade Pressure Vessel Group, apparently ASME Section VIII has not adopted the new flange rating revisions in B16.5. I wonder what the status is with B31.3 and other piping codes as well.
Your warning is well taken, as that is what has happened in this case. We had set a design pressure based on maximum flange pressure rating at a corresponding temperature. The relief valve vendor came back with a different pressure class mating flange than expected. I guess it will be interesting to see how or when the associated codes come into agreement.

Appendix E of B31.3 lists referenced standards. Both the 2002 Edition and the new 2004 Edition show the 1996 Edition for B16.5 with the 1998 Addendum.