I think what #3 is saying is that let's say you have a 6" underground, but reduce at the riser to 3" because that is all of the system demand you have, you can flow a 3" open outlet at the riser to flush the underground, and that is equal to the maximum flow rate available to the system under fire conditions. It will create the maximum velocity in the underground pipe that that pipe will ever see, unless it breaks while it's still 6" or the system is altered and the riser increased in size.
Thom McMahon, SET Firetech, Inc. 2560 Copper Ridge Dr P.O. Box 882136 Steamboat Springs, CO 80488 Tel: 970-879-7952 Fax: 970-879-7926 Subject: Underground flushing velocities NFPA 24 says the following: (3) Maximum flow rate available to the system under fire conditions _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.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)
