Thread: standpipe ops.
09-26-2000, 12:11 PM #1jr17716921Firehouse.com Guest
During a recent walk-tru of a remodled mill found a problem never before seen. The mill is about 90 years old and four stories in height. The mill is equipped with a standpipe and a sprinkler system. The problem is there is only one fire department connection to supply both the standpipe and the srinkler system. The question is how would you pump the fire department connection?
09-26-2000, 07:38 PM #2ffengFirehouse.com Guest
Mills of this vintage often do not have a seperate standpipe system. The hose connections are often fed directly from the sprinkler system. Are the hose connections 2 1/2" or 1 1/2"? Are the hose connections located throughout the building or are they directly adjacent to a riser? If they are located throughout the building, you should also check on the supply piping to hose connections. 1 1/2" hose connections can often be supplied with long runs of small diameter piping. Hydraulic calculations would have to be run to see what flows/pressures you could expect. In general, there is nothing inherently wrong with combined systems and pumping a combined FDC.
I would check on the mill's overall sprinkler protection and water supply. What are the occupancy demands and can the sprinkler systems meet those demands? What is the water supply, fire pump(s) off municipal, pump and tank, etc. How reliable is it? Can it meet greatest sprinkler demand? Can it meet greatest sprinkler demand and supply hose stream at the same time?
Key issues I would consider regarding manual streams are: where is the water supply coming from, don't steal from sprinklers; where will pumper(s) take supply - yard hydrants or municipal hydrants? How long will handlines have to be considering hose connection locations and building size? Can the mill water supply with or without added pumpers meet pressure requirements for longer handlines of smaller diameter hose and still provide good flows?
Hopefully this gives you some additional items to consider. Two key issues to consider - don't rob the sprinklers of water and do a very careful risk analysis before committing interior crews deep into such a structure if the fire gets away from the sprinklers. Firefighters first, property a distant second.
10-02-2000, 03:54 AM #3ffpfaffFirehouse.com Guest
Well put ffeng. You could try field hydraulics from the IFSTA Pumping apparatus bookand follow the calculations that work for you. We use the theory that a Class A pumper is most efficient at 150psi , therefore calculate the length of the hose to the connection, 25psi for the connection, 5psi for each floor above the 1st floor and go for it. Try doing a calculation on paper(the lon way) and it comes out pretty close.
Good Luck IAFF 469
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