George, You have a way to bleed the air off of the system at the high point? This sounds like a good idea. Cold you explain some more on how to make this happen?
Thanks, Ergo On Fri, Feb 27, 2009 at 8:38 AM, George Church <[email protected]> wrote: > Venus and Mars. I raise hypothetical questions, you hunter-gatherers answer > the question instead of pursuing the issue of statistics :) and how to find > them. Quite a change from the suggester of a group hug:) > > I agree on the BFP, MIC, and although we often have the ITC on a riser > manifold, we generally have a way to bleed the air off the high point to > avoid false signals. > > Good point on calculating the Expected Value, taking the frequency a step > further and including impact. > > glc > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Chris > Cahill > Sent: Friday, February 27, 2009 11:02 AM > To: [email protected] > Subject: RE: statistics > > But if you are doing a risk analysis you are forgetting the outcome side. > For example, failure of a BFP to protect the public in theory could be > catastrophic to many if not all on the water supply. Failure of a BFP in a > fire should only affect one building. On the theoretical side some may die > from the fire and/or billions of $ lost but it ain't getting a whole city > sick or contaminating an aquifer used by 10's of millions. So the rates > alone are irrelevant. You need to take risk and multiply it by loss then > you have the answer on which way to go. Don't get me wrong BFP's are a > bunch of hooey. > > 1st question - about 0 for both, BFP's are a waste of money in the first > place. > > 2nd - MIC is an issue we need to or will be dealing with more often. > Remember ESF only seems at this point to be an Allied problem. I vote treat > the MIC. > > 3rd - off the end gets some/most air out reducing false alarms and > eliminating some air/water interface rusting. MIC coatings help with the > added oxygen in the water. I vote end. > > 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 > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of George > Church > Sent: Friday, February 27, 2009 9:15 AM > To: [email protected] > Subject: statistics > > Just as we recently discussed that we don't know how many heads a year are > installed, or how many have been installed in the past 100+ years, when > discussing unexpected activations, statistics of some order of magnitude > would be helpful in numerous other things. > > Which occurs more frequently, failure of a backflow to protect the public > supply, or failure of a backflow to allow full forward flow of water to a > sprinkler system when needed? > > Is the possibility of MIC greater than the likelihood of ESF from MIC > coatings? This would aid us in deciding, on systems comprised of combo > steel > and CPVC, if we want to use uncoated pipe (more susceptible to MIC) or risk > Environmental Stress Fractures? > > Is it better to run the ITC off the riser and limit the new oxygen into the > system, or run it off the tail end and check for blockage? > > There are countless other items we have no data upon which to base our > decisions. Our best guesses may be completely wrong- guess our batting > average would be no better than 50-50, and likely the answer may be based > on > something more important but not considered. > > glc > > -----Original Message----- > From: George Church [mailto:[email protected]] > Sent: Friday, February 27, 2009 10:07 AM > To: '[email protected]' > Subject: RE: Fire marshall > > Just as a plumber would assume testing a sprinkler backflow is limited to > the backflow portion of the test, not aware of the forward flush we're more > concerned about. > > glc > > > _______________________________________________ > 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]<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]<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]<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)
