Todd: We do these all the time. The first thing to do is check with the Chief and see what his pumper is able to draft at the altitude of the tank. (Hale 1250 GPM pump @ 7000 ASL drafts about 11'-0" with over 350 Hp connected) What connection they use for their hard line? Storz or NST and the size.
This is another reason we use Xerxes tanks. SR20 load rated so the draft can rise up out of the tank and the engine could actually park on the tank to draft. So let's say from the water line in the tank to finish grade is 8'-0" and the tank is 12'-0" dia. With 6'-0" of cover. Will it draft? Yes and it will continue to draft all the way to the bottom as long as they don't lose the draft below 11'-0". Here is the site for our Dry Hyd. Manual: http://steamboatsprings.net/sites/default/files/page/1420/dry_hydrant_manual .pdf Avoid Horz. Pipe in the draft. We typically see vertical to grade then a 90' storz or NST fitting. If you need to get away from the center of the tank two 45' ells one at grade and one at the connection height work. Ok so what he's saying is that this is an emergency back up to your pump. You don't need to ADD anything for additional hose allowance. Our Fire District, has about 25 similar tanks. They intend to use that water to supplement shuttle tenders if there is a fire nearby, or to use it for wildfires, besides as you have described. Since the tank is located on private property, I suggest that the FDP get a use agreement with the owner. Ours includes the FDP refilling the tank after use within 24 Hrs, and if the tank is used for potable water that that refill be done by a water service with FDA approve tankers, or if it's well supplied that the district repay $X.XX per gallon used. 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 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Todd Williams Sent: Tuesday, September 22, 2009 2:41 PM To: [email protected] Subject: draft line from suction tank. I am working on a project with a small pump and a buried suction tank. The design was based on sprinkler demand alone since there are no hydrant connections on the system. Now the local AHJ has come back and says he wants a draft line on the tank. The sprinkler system will take approximately 11000 gallons in the 15000 gallon tank. He claims he would only use it if the pump failed to start. Being this is a rural department in an area with no public water supply, I have a bit of a problem believing this. If I had to include a hose demand from a draft line on a tank, would the standard hose demand be practical? The building is all LH and the hose demands would be 100 gpm. Todd G. Williams, PE Fire Protection Design/Consulting Stonington, Connecticut www.fpdc.com 860.535.2080 _______________________________________________ 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) _______________________________________________ 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)
