Don, The heat tracing for branch lines have to listed. The heat tracing is not listed yet. We did a Technical Update last August on this subject. See below 3rd paragraph.
Tom Wellen - AFSA We have a building with an unheated attic space of approximately 3,900 square feet. The project specifications are requiring a wet fire protection system with the piping to be insulated and heat traced to prevent freezing. Is it the intent of Section 8.16.4.1 to allow this method of freeze protection for an entire system in lieu of a dry type system? Would sprinkler heads be protected from freezing by heat tracing branch line piping?" We have reviewed the 2007 edition of NFPA 13 as the applicable standard. Our informal interpretation is that heat tracing is permitted in lieu of a dry pipe system but heat trace products are not yet available for branch line applications. A manufacturer has reported that there is no heat tracing cable available with a listing for branch lines since the testing procedures have not yet been developed or defined by FM or UL. UL has been contacted and they confirmed that there is not yet a test standard and that a significant amount of work must be completed on the ANSI standard before testing can begin. A time estimated completion date has not yet been identified. The heat tracing will affect the sprinklers thus the testing standard will have to address this issue. The concern is that the tracing wire may overheat the branch line and activate the sprinkler. The current UL listing is for use on piping between the system control valve and the system branch lines, but does not include the branch lines. Thus a dry pipe or antifreeze system should be installed for attic space unless the space is heated above 40 degrees F where a wet pipe system could be installed. On Mar 24, 2009, at 10:35 AM, Don Lowry wrote: > What is the main reason we cannot insulate and heat strip > Branch lines, I have always pointed out to every owner, AHJ > and engineer that it is "unacceptable practice" per > standard, however several authorities here in Texas have > been allowing and encouraging this practice. I need to give > them a good reason other than the standard says so. The > handbook doesn't quite explain this. > > > > Thanks > > > > > Don Lowry, R.M.E. > > Vice President > Dickerson Fire Protection, Inc. > (254) 662-3777 office > (254) 379-1442 Cell > www.dickersonfire.com > > P Be Responsible! Print this email only when necessary. > > > > > > > > _______________________________________________ > Sprinklerforum mailing list > http://lists.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) > _______________________________________________ Sprinklerforum mailing list http://lists.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)
