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
