DEAR ALL,

I am looking for component response factor for piping. in the CAESAR II user guide found that RP=12 for piping according to ASME B31 code.

But I searched in ASME B31E and not found that value.

Please guide me in which section of ASME B31E says that value 12 for piping.

if you have please share screen shot of that section.

B31.3, "301.5.3 Earthquake. The effect of earthquake loading
shall be taken into account in the design of piping. The
analysis considerations and loads may be as described
in ASCE 7. Authoritative local seismological data may
also be used to define or refine the design earthquake
loads."

However, in order to be conservative, use 31E value for Rp.

HI MARIOG,

THANKS FOR YOUR QICK REPLY.

BUT I NEED Rp VALUE DEFINED IN WHCIH SECTION OF 31E. I COULD NOT FIND THAT VALUE.

I think you need ASME B31Ea-2010.

"When the seismic design force is computed based
on para. 13.3.1 of ASCE 7, or a similar standard, the
parameter ap shall be 2.5 and the parameter Rp shall not
exceed 3.5 when applying the stress limits of para. 3.4.

When the alternative design methods of para. 3.5 are
used, the derivation of seismic inputs shall be based on
parameters compatible with the design method being
utilized."

HI MARIOG,

THANK YOU VERY MUCH FOR YOUR QUICK REPLY.

YES I NEED ASME B31Ea-2010. REASON IS WHEN I REFERING CAESAR USER GUIDE OF 2011(VERSION)I FOUND BELOW STATEMENT IN PAGE 1034.

"Rp = Component response modification factor, from Table 13.6-1

= 12.0 for "Piping in accordance with ASME B31... with joints made by welding or brazing"; values range as low as 3.0 for other joints and for less ductile materials."

BUT NOW AS PER YOUR REPLY IT SHOULD BE BELOW 3.5. WHICH ONE IS RIGHT APPROCH. IS THE GUIDE IS WRONG CONCEPT?

I AM REALY CONFUSED.

There isn't a "right approach" as you cannot guess what actually will happen in a specific seismic event.

Rp is just a factor that counts ductility effect. Basically, in building seismic codes, a high value is associated with the ability to develop (in specific places, by Designer choice) some plastic hinges. Probably being to the limits of elastic calculation with Rp=12 means for the system to survive with non-elastic strain. Which may be acceptable in some circumstances or not acceptable in others. Just my interpretation of that value of Rp=12, of course.

B31E is a prudent approach and anyway it considers much more things than seismic accelerations and Rp values.

ok thank you very much mariog I agree.