Further to this thread, I think it needs to be considered what the FDC is there to achieve. I am working on a "back to basics" here as our Sprinkler Rules are different to the US so I don't know how your AHJ's view this. In the first instance the FDC is to allow the Fire Dept to augment or supply water to a Fire Sprinkler System if the water supply becomes inadequate to meet the system demand. An FDC should be fitted to all sprinkler systems. I consider the point of connection for the FDC should be downstream of the Control Valves. If the point of connection to the system is "downstream" of the Alarm, Deluge or Dry Pipe valve it has the added advantage of allowing water to be pumped directly into the Sprinkler System if the Main Stop Valve or Alarm/Deluge/Dry Pipe valve is stuck shut. In the case of the Dry Pipe Valve arrangement a Subsidiary Stop Valve or Check Valve may be useful downstream of the point of connection for testing purposes.
In New Zealand we use our Fire Service Inlet(FSI) for another purpose in addition to supplying water to the Sprinkler System. It is always connected downstream of the Control Valves. We use our FSI(or FDC) as a flow test outlet so we can flow the full design flow through the total supply pipework and the Control Valves and thus proof that the water supply(s) are adequate and the valves will all open fully. This test is done every two years during a full inspection/survey of the Sprinkler System by a Certified Testing Company. We do not fit a Check Valve in the FSI connection but instead use a drip tight diaphragm or butterfly stop valve which is located at the FSI in a cabinet on the exterior of the premises. The size of the FSI connection and the number of hose connections varies from one to six depending on the design flow of the system( one for each 1350L/min). For High Hazard systems with flows over 3500L/min we fit a 100mm or 150mm RG outlet to use to fit our test flow metering device(usually an orifice plate unit with certified calibrated gauges) onto. Trust this is of interest. Russell Gregory Christchurch New Zealand -----Original Message----- From: Sprinklerforum [mailto:[email protected]] On Behalf Of markloganryan Sent: Saturday, 7 February 2015 2:51 a.m. To: [email protected] Subject: RE: FDC on a dry system The book shows single preaction systems fdc on the system side with a check valve after fdc supply. Which means the trim to the valve must connect above that check valve. (Never ran into this situation). I suppose the same could be done with a solenoid released dry valve. Sent from my Verizon Wireless 4G LTE smartphone <div>-------- Original message --------</div><div>From: Lamar Vaughn <[email protected]> </div><div>Date:02/06/2015 3:13 AM (GMT-07:00) </div><div>To: [email protected] </div><div>Subject: Re: FDC on a dry system </div><div> </div> I recently researched this issue for a customer just to make sure I was right. I have been in this industry since 1969, and FDC's have NEVER been allowed on the system side of the dry pipe valve. Respectfully Submitted, Lamar Vaughn, SET _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
