The highs and lows of water flow
The SAM system is the Goldilocks of water pressure – it gets it just right
Sponsored by IDEX Fire & Safety
By Laura Neitzel, FireRescue1 BrandFocus Staff
The advent of hand pumps and water hoses marked the end of the bucket brigade near the end of the 17th century. Since then, most firefighting has depended completely on pressurized water from a variety of sources, including city water hydrants, tanker shuttles, lakes, ponds, rivers, water tanks and the occasional swimming pool.
Each source comes with its own set of risks and challenges. Every time a line comes on or off means a change in water pressure that needs to be optimized to get the “wet stuff on the hot stuff.”
It’s a task much easier said than done. Too little pressure, and firefighters can’t get water where it needs to go. Too much pressure, and fire crews are put at risk of losing control of the line.
“A lot of times you’ll have more pressure coming in off the hydrant than you need going out to the nozzles,” said Chief Larry Moser of Mount Hope Fire Department (MHFD) in North Carolina. “That becomes a challenge of how to control the water coming in, so that if you’ve got 120 psi coming in and you only need 90 at the nozzle, you’ve got to do something to control that extra pressure.”
Greg Stofer, who retired after 34 years in the fire service in Nebraska, explains that, at a minimum, the pump operator must gate down the pressure to make sure the firefighters on the end of the line don’t get a spike in pressure.
Control the spikes
Stofer has seen several instances during changeovers when a pressure spike caused the hose line to blow off the coupling. Such a loss of control of the hose due to excessive pressure can require shutting down operations while the pump operator manually decreases pressure.
It can also be dangerous. The reaction force of excessive pressure coming out of the nozzle means crews must use brute force to control the hose. Not only is that exhausting for crews, trying to control a flailing hose can lead to muscle strains and other injuries.
“I went to the hospital myself with stitches, a broken toe and a shoulder injury from a hose that got loose,” said Moser. “Part of that was attributed to the pressures on our hydrants.”
The pressure on a pump operator isn’t measured only in pounds per square inch.
“Our pump operators have to be skilled in all the different facets of pump operations because at any given time you could be on one extreme or the other,” said Moser. There is tremendous responsibility in getting the right amount of water to the fire safely. Firefighters may be 100 feet inside a burning building, reliant on a steady water flow to put out the flames and cool the area. Losing water in such a situation can mean lost lives.
“If my eyes are glued like they’re supposed to be, it’s real important in these higher-pressure areas that I’m paying attention to the pressure gauges,” said Stofer.
However, most pump operators can tell you that it’s something you need to get a feel for – and even then, it can be hard to get right.
That’s where new technology can make a huge difference.
“The SAM system, especially in higher-pressure hydrant areas, is so quick to gate and to take care of those pressure spikes,” said Stofer. “And honestly, it’s just something that no matter how much experience and training I have, I can’t do it as good or as fast as that system does.”
Alleviate hydrant issues
About 10% of MHFD’s water sources come from pressurized hydrants, but as new hydrants are added in growth areas, “hot hydrants” are an issue of growing concern. About the time when he was forming a committee to replace a 20-year-old apparatus, Moser came across the SAM system at a state fire conference.
“It was the answer to an issue we had been looking for an answer to for quite some time,” said Moser. “If your municipality or water system has higher pressures coming in than what you pump out, this is the only way to go. If your pressure drops at the hydrant, or if it changes, the SAM system takes care of all that for you.”
When the new fire apparatus was delivered to MHFD in March 2021, it had SAM system control panels on both sides of the truck. “It has freed up the pump operator to be able to operate the truck from either side,” said Moser, “which has also freed them up to help more as the scene evolves, especially in the first 10 minutes when things are really getting going.”
In addition to automatically gating down a high pressure, the SAM system also controls individual discharges simultaneously and can recognize low-flow situations as well as high. It will instantly alert the pump operator in the event of a problem, such as a change in pressure if a line gets kinked and water flow is restricted.
“It’s a huge advantage in the higher-pressure systems or the hot hydrants because it reacts so quickly,” said Stofer. “The individual discharge control is a huge safety factor. It allows me to look at a screen, and it’s automatically going to take care of those pressure differences.”
The way of the future
Moser has been surprised at how easy the SAM system has been to operate and how even the more experienced firefighters recognized that the software is “so well developed that it does what it’s supposed to do and takes so much pressure off the pump operator. You don’t have to do all this stuff to make sure the guys inside are safe. The truck does it for you.”
Younger firefighters entering the profession are already comfortable with the touchscreen technology and can learn the SAM system in about 10 minutes. Moser says it serves as a recruiting tool when prospects recognize the department is willing to invest in technology that makes things safer and easier.
“When I see technology that can make our job better, the outcome of our job better, I’m all for it,” said Moser. “Everybody in the fire station that was involved with the demos bought into it because they recognize this is the future. Because we don’t buy trucks every year, if we didn’t adopt it now, we might be looking at 10 years before our next purchase. We didn’t want to miss out on moving forward.”
Get more info at SAMflows.com.
In case you missed it: 4 ways IDEX Fire & Safety’s SAM system transforms traditional pump operations