That's my understanding also. These things are designed to open a little lots of times and if not fully opened regularly they might not fully open when needed. I do agree that a main drain is probably sufficient for low flow systems but how much can you actually flow through a 2" pipe. A quick search shos my 2" schd 40 black steel table stops at 335 gpm.
On Fri, May 30, 2008 at 5:13 PM, scott mitchell <[EMAIL PROTECTED]> wrote: > I don't think the intent is to measure the pressure drop across the device. > Based on what I've read and what I understand to be the intent of the minimum > standard, if you measure 400 gpm and the system demand is 379, then you've > conducted a full flow test at system demand. > > UL does not test the assembly for proper operation after an extended period > of time with no water movement. So, this is a means of exercising the > assembly and showing that the demand flow can make it through. > > While not prescribed by 13 or 25, prudent ITM procedures would include > measuring the pressure drop across the device. > > Scott Mitchell > > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > To Unsubscribe, send an email to:[EMAIL PROTECTED] > (Put the word unsubscribe in the subject field) > -- Ron Greenman at home.... _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
