4 FM quick reads on fire sprinkler
1. Fire Sprinkler Maintenance Steps
Just because the toilets are flushing and the taps are running without issue does not mean it is safe to presume the water supply to the fire sprinkler system is good to go.
Proper sprinkler operation is only ensured through proper and routine maintenance of the system. It's like flossing your teeth — you just have to do it. But when you skip a flossing you don't risk getting caught on the wrong end of a lawsuit or have imperiled lives, so it behooves facility managers to stay on top of their maintenance.
One step is a visual inspection of the sprinkler heads. These can fail to operate due to being painted over, clogged or blocked, says Chris Jelenewicz, program manager, Society of Fire Protection Engineers, in a recent Building Operating Management article. He has even seen a situation where a dropped ceiling was installed without moving the location of the sprinkler heads below the new ceiling heights.
Another step is the main drain test. After establishing a baseline pressure reading, subsequent readings will show if there's a significant drop in pressure. Drops in pressure could be caused by partially shut valves in the underground supply, which would starve the fire sprinkler system of adequate pressure while still seeming adequate in other applications, such as toilet flushing. Another cause could be corrosion in the system, which would interfere with moving high volumes of water at high pressure, he says.
Proper documentation is another important component of testing. Record what tests were conducted when, what the findings were and what is the proposed course of remediation for any issues uncovered.
Hopefully, the fire sprinkler system will never be called into action. But — to borrow the catch phrase from a certain insurance agency — in the event of a fire you won't want to hope the fire sprinkler system is ready. You'll want to know so.
Find the article here.
2. High Volume Low Speed Fan and Sprinkler Operation
High volume low speed fans (HVLS) were invented to keep cows cool in barns, but they've been increasingly adopted in the commercial facilities realm. They can move a lot of air with very little power. Plus they look cool, it's this huge fan, with some models having a kind of industrial chic thing going on.
Dan O'Connor, chief technical officer with AON Fire Protection Engineering, recently spoke on HVLS' impact on automatic fire sprinkler systems for NFPA's Fire Protection Research Foundation. In his presentation, High Volume Low Speed (HVLS) Fan and Sprinkler Operation Research Program Phase II, the scenario he spoke on was a warehouse setting, with boxes of goods stored on racks.
At the heart of the findings of his research is that if the fan or fans are not shut off during a fire, the automatic fire sprinkler system will extinguish the fire, but not before some significant damage has occurred. In one scenario tested with no fan-shut off, between five and 12 pallets were damaged and the fire jumped aggressively across an aisle. In the "fan on" tests, 12 sprinkler heads went off.
In contrast, when the fans were shut off, between a half and two and a half pallets were damaged and only four sprinkler heads activated. Now there were a lot of very specific parameters that you'll have to check out the original research for, but the conclusion was that sprinklers can protect with fan shutdown no later than 90 seconds after waterflow of the first sprinkler. It can take a fan up to a minute to stop rotating after it's shut off. Acceptable ceiling height depends on sprinkler type.
From this research the following proposals are being made for NFPA 13, under the General Design Criteria.
- Fans can have a max diameter of 24 feet.
- The fan has to be centered between four adjacent sprinklers.
- The vertical clearance from HVLS fan needs to be a minimum of 3 feet.
- All HVLS fans have to be interlocked to shut down upon receiving waterflow signal.
High Volume Low Speed (HVLS) Fan and Sprinkler Operation Research Program Phase II