Ron, Yes, All of our engines (pumpers) carry a minimum of 15 ft of soft "suction" hose (also referred to as "soft sleeve"). In our jurisdiction the main hydrant outlet (steamer connection) is 4-1/2". Soft sleeve is 6" double jacketed or synthetic coupled down to 4-1/2" thread at the hydrant and a full 6" at the engine suction connection. Our standard operating procedures stipulate that residual supply pressure shall not be less then 20 psi on water supplies other then at draft. This coincides with the AWWA standard and 2006 IFC B102 Fire Flow. However it should be noted that the 20 psi reference in he IFC is the minimum acceptable pressure when evaluating the adequacy of water supplies for fire flow. It should also be noted that a fire department is not bound to those provisions and a command officer well within his/her right to pump at lower residual pressures where necessary to assure the safety of building occupants or firefighters.
There's really no clear consensus on this, perhaps because of the unpredictability of firefighting. John Normans Fire Officers Handbook of Tactics stipulates residual pump pressures of no less then 10 psi. With other then hard suction (hard sleeve) the risk of hose collapse is increased with lower residual pressures. It takes only a moment for a pump operator to experience an increased flow at low inlet pressure followed by supply line collapse and loss of water supply. In that regard the 20psi cushion provides an increased margin of safety. I've pumped large fire flows at 10 psi residual with no apparent effects to the water supply, however given the choice 20 psi is more comfortable. In conclusion if we're speaking of design criteria, then 20 psi is your number. As for firefighting, ya gotta been in the chiefs shoes that day. Hope that helps John Drucker Fire Protection Subcode Official (AHJ) Red Bank, NJ Engineer- Engine 182 Middletown Township Fire Dept-Station 8 Middletown, NJ -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Fletcher, Ron Sent: Tuesday, July 08, 2008 6:50 PM To: [email protected] Subject: FD Pumper Suction Hose Does anyone have experience with 4" pumper truck suction hose of the soft variety? According to a City FPE Phoenix FD requires 20 psi (flowing) at private hydrants to avoid collapsing the soft suction hose. Sounds fishy to me but I have no way of knowing. I can understand not taking the city main below 20 psi but I don't see why a private fire main can't go below 20. Ron Fletcher Aero Automatic Phoenix, AZ _______________________________________________ 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) _______________________________________________ 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)
