I think we need to go back to the whys. As Duane found the main drain's purpose is for draining the system, with any necessary auxiliary drain plugs or valves for draining trapped portions. The "Main Drain Test" has nothing to do with this but is for establishing a baseline of conditions (static pressure when closed and residual pressure when open) pertinent to the water supply at the time of installation. The subsequent tests are to compare the data now to the original data (baseline). I think earlier in this discussion, or in that other recent main drain thread, we established that the main drain needs to be somewhere on the vertical or horizontal portion of the supply riser before the first split. I think we also agree that for the "main drain test" we need to use the main drain. I'd suggest then that for the test it is irrelevant whether the test point (main drain) is before or after the pump, or whether the pump is running or not, as long as the conditions of the test (point of test, pump on or off, and I'd add time of day and whether weekend or weekday depending on the normal demands on the city loop relative to the original test day and time) for today's test duplicate the conditions for the baseline test.
Think of tire pressure as an analogy. The recommended (baseline) pressure is always under a certain load and with hot (in use) tires. Checking pressure early in the morning after a snow night, before you even start the car up will give you a low pressure reading if on the way home yesterday you checked at the gas station close to your home after a twenty minute drive and made them perfect. On Fri, Dec 13, 2013 at 7:31 AM, Smith, Steven D. (CSFD) < [email protected]> wrote: > I can vouch for this as I had the honor and privilege to work for him a > while back! > > Steve > -----Original Message----- > From: [email protected] [mailto: > [email protected]] On Behalf Of Matsuda, > Richard > Sent: Friday, December 13, 2013 8:26 AM > To: [email protected] > Subject: RE: Fire Pump Room Main Drain > > This subject has been a pet-peeve of mine for the past 35 years. > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > -- Ron Greenman Instructor Fire Protection Engineering Technology Bates Technical College 1101 So. Yakima Ave. Tacoma, WA 98405 [email protected] http://www.bates.ctc.edu/fireprotection/ 253.680.7346 253.576.9700 (cell) Member: ASEE, SFPE, ASCET, NFPA, AFSA, NFSA, AFAA, NIBS, WSAFM, WFC, WFSC They are happy men whose natures sort with their vocations. -Francis Bacon, essayist, philosopher, and statesman (1561-1626) A problem well stated is a problem half solved. -Charles F. Kettering, inventor and engineer (1876-1958) _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
