Would I be correct in making this statement? Flex heads & earthquakes

[SprinklerDesigner2]

In using flex heads per NFPA #13 2007 would I be correct in making this statement?

"In many areas of the country where earthquakes are a major concern the use of 'flex head" drops to pendent sprinklers are among the preferred method of offering the required flexibility and protection."

Also;

"The use of 'flex head' drops seems to be the preferred method of offering the required protection in large parts of western states and those areas in the Midwest and southeast prone to earthquakes."

You are going to have to excuse me spending most of muy life in Michigan/Florida/South Georgia sway bracing and earthquake protection is among my weakest areas.

 

[DavidCR]

Just a point to consider:

I think that the main risk on an earthquake with sprinkler pipes is where the bigger diameter horizontal pipes (mains,and branches) receive the seismic forces, that would lead to pipe fracture, leaks, etc.

I think that flex heads help for the general flexibility of the system but their main funtion is to help with the interaction of the sprinklers smaller pipes and sprinkler itselves with the non structural members such as suspended ceilings, gypsum, etc.

So in my opinion with seismic considerations flex heads help only on the lighter side of the seismic protection.