Ah, but the main drain is stipulated by the system riser size, not all systems require a 2" drain only those 4" and larger. On modern systems it is very common for one large feed main to feed several "Zones" each zone could be very large or small depending on the building layout or local requirements, if each of these zones had an alarm check valve as was required before the advent of these "Riser Manifolds" would they not have main drains, and be tested as such? Is the feed main not just an overhead extension of the underground supply piping to each system riser?
Jamey -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ron Greenman Sent: Wednesday, April 11, 2012 5:57 PM To: [email protected] Subject: Re: main drain test We get caught in semantics often because we use the same words to describe different things depending on context. For instance, every pipe that goes up, except sprig-ups, is a riser, but that doesn't necessarily mean system riser. We use the term main drain to describe the primary drain valve at sectional control valves to differentiate them from small auxiliary valves but that doesn't mean that it's the system main drain. In fact sectional drains in high rises are typically 1 1/4", not big enough for the main drain. On Wed, Apr 11, 2012 at 2:22 PM, Matsuda, Richard < [email protected]> wrote: > Jamey, > Yes, you are correct...well at least partially correct. I didn't read > all the previous questions or comments. > > Yes, you can do a main drain test to test the supply using the > furthest riser, but you won't be able to determine the exact location > of any obstructions if the test pressures are low...and you still have > to compare the results to previous tests. > However, conducting this one test doesn't mean that you don't have to > test each system individually, too. > > The FM system of counting the turns insures that the valve is > completely open/closed, and the drain test insures that it's not broken inside. > rick > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Jamey > Prentice > Sent: Wednesday, April 11, 2012 4:12 PM > To: [email protected] > Subject: RE: main drain test > > Rick, > > That is my understanding also, but the original question was " If > the intent of the main drain test is to test the supply, can you > accomplish that by flowing the largest or the furtherest from the > riser instead of flowing each one individually? So the answer would be > no, because you are not just testing the supply? > FM Red Tag actually requires that the valve turns be counted on > open/closed and system residual pressures be recorded for each closed > valve. > > Jamey > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of > Matsuda, Richard > Sent: Wednesday, April 11, 2012 4:43 PM > To: [email protected] > Subject: RE: main drain test > > Jamey, > The main drain test conducted on the incoming water supply to the > building is performed to insure adequacy of the water supply compared > to previous tests. Extreme changes in static or residual pressure will > indicate changes in the municipal supply and/or obstructions in the > piping including closed or partially closed inline valves. > > The tests conducted on the sectional valves are done to insure the > valve is still operational (that it will close when required) and the > drain test is done to make sure that it is fully open after you closed > it for the test. > This procedure will indicate any dropped gates or broken valves where > the valve appears to be open externally, but it is actually close > internally because it is broken. > > rick matsuda > city of dallas > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Jamey > Prentice > Sent: Wednesday, April 11, 2012 3:21 PM > To: [email protected] > Subject: RE: main drain test > > This one has always confused me, If you are not required to perform a > residual drain test on each sectional valve assembly why does the > manufacturers literature state to do so? Have included Tyco's > requirements for reference: > The following inspection procedure must be performed as indicated, in > addition to any specific requirements of the NFPA, and any impairment > must be immediately corrected. > Alarm/Flow Test Procedure > Step 1. Place the test & drain Valve in the "test" position. > Step 2. Fully open the drain valve. Make certain that drainage water > will not cause any damage or injury. > Step 3. Verify operation of associated alarms. > Step 4. Close the drain valve. > Step 5. Place the test & drain Valve in the "drain" position. > Step 6. Verify that the residual (flowing) pressure indicated by the > pressure gauge is no less that originally recorded for the system when > it was first installed. > Step 7. Close the drain valve. > Step 8. Verify that the static (not flowing) pressure indicated by the > pressure gauge is no less that originally recorded for the system when > it was first installed. > > Jamey > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > -- 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) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachment s/20120411/afec2c9c/attachment.html> _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
