Many years ago, we wrote an article about the need to pre-plan fire department connections (FDCs) so that a sprinkler or a standpipe system can be properly supplied. In the case of standpipes, this is needed to either provide sustained flow or to supplement flow, and in the case of a dry standpipe, to provide all the water.
In the case of sprinkler systems guidelines are provided by NFPA 13 which is the standard that governs automatic sprinklers and intends that fire department connections are to supplement the water supply. This could be to boost pressure, boost flow, or increase the duration of the supply. They can also be used during a water supply outage to keep the sprinkler system in service.
A recent fire at a tire warehouse offers a clear example for the need to support a sprinkler FDC. The sprinklers at the warehouse had controlled a fire and were consequently turned off so that the fused heads could be replaced. While they were turned off, there was a second fire. Because of the delay in reopening the valve, too many sprinklers opened for the facility pump to keep up. The fire department connection was there so that the water supply can be boosted.
Another example is warehouses equipped with Early Suppression Fast Response Sprinklers, which most new warehouses include. They are designed to flow 12 sprinklers with only 250 GPM (1900 l/min) reserved for hose streams. The water supply is sized for 60 minutes.
ESFR sprinklers work on a similar principle as the fire department blitz attack; meaning lots of water to the burning material fast. They work very well if all the rules in NFPA 13 are applied. However, it does not take much of a change to violate these rules. Supplying FDCs quickly can be the difference between a little extra water damage and a total loss.
To be effective, the FDC must be supplied quickly by one of the first arriving pumpers. It should not be an afterthought.
With the need to quickly supply these connections established, it is important to know where they are, what they supply, and how to differentiate them from other similar looking connections.
Common connections that are grouped in one place on the building are standpipe connections for different building zones, fire pump test connections. Other connections could be fuel fill connections, and underground cistern drafting connections. These should be labeled of course, but sometimes the labels are hard to read or might not be there at all.
Fire department connections will have female threads or Storz connections. Fire pump test headers will have male threads, usually with outside control valves and often with an arrangement as shown in Figure 1. Other arrangements are shown in Figures 2 and 3.
Other industrial applications we have written about in the past include:
- Semi-fixed foam systems to be supplied with foam solution from foam apparatus,
- Semi-fixed CO2 systems to be supplied from CO2 apparatus,
- Semi-fixed foam system where foam concentrate (not solution) is supplied from the foam concentrate tank on a foam pumper to a 1.5” (38 mm) FDC,
- Semi-fixed water spray system to protect a butane sphere,
- Nitrogen injection systems.
A semi-fixed system means that the piping is in place but is not connected to an extinguishing agent supply. The agent must be supplied by fire apparatus. A dry standpipe is a semi-fixed system, however dry standpipe is the common term.
Fire department connections are a critical part of fixed protection and must be thoroughly understood in order to successfully operate at facilities equipped with them.
John Frank is Senior Vice President of the XL Catlin’s Property Risk Engineering / GAPS Loss Prevention Center of Excellence, where he is involved in loss prevention research and loss prevention training. XL Catlin’s Property Risk Engineering / GAPS team provides property loss prevention consulting and delivers individually tailored solutions to protect and enhance property, production, and profit. With approximately 220 engineers and consultants in 18 countries, the team brings clients occupancy specific experience as well as deep knowledge of specific hazards across industries. Businesses that are moving the world forward choose XL Catlin as their partner.
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