Per Dyna-Thread's data sheet, CRR is ". . . the calculated wall thickness AT THE BASE OF THE FIRST EXOSED THREAD, ASSUMED TO BE THE WEAKEST POINT OF THE PIPE LENGTH. Dyna-Thread and sch-40 have the same calculated wall thickness at this point and are both assigned the same CRR of 1.00." *Capital letters added by me*
I really don't understand the 'how' of why some threadable thinwalls have a CRR of 1, but some do. I'm curious if a CRR of 1 allows that particular pipe to use increased hanger spacing (equal to that of sched 40). If this were a 'listing' question, I'd call Tyco. But this seems to be more of an interpretation of section 9.2.2.1. Ed Kramer Littleton, CO > > Well let me be more clear CRR is based on wall thickness. Corrosion is > much > more complex when the chemistry of the pipe is different. CRR does not > tell > the story of corrosion but as best I know it's the only thing we have to > put > our hand on besides WAG. > > Chris Cahill, P.E. > Fire Protection Engineer > Sentry Fire Protection, Inc. > > 763-658-4483 > 763-658-4921 fax > > Email: [email protected] > > Mail: P.O. Box 69 > Waverly, MN 55390 > > Location: 4439 Hwy 12 SW > Waverly, MN 55390 _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
