For decades, the performance ceiling for compact mobile apparatus fire pumps has been 2,000 gpm. W.S. Darley & Company’s new ZS 3000 pump shatters that ceiling with flows in excess of 3,400 gpm.
“With a lift, the pump is actually rated at a 3,500 gpm industrial rating,” said Jason Darley, accounts manager for the North American pump division. “Using positive intake pressure, it will do more than 4,000 gpm. As for industrial use, with a pressurized source the sky is the limit.”
At 100 psi or higher, Darley’s new ZS pump is the highest flow pump available on the market today, Darley said. At 240 psi, the ZS 3000 produces the 2,650 gpm required to meet a special international rating.
Darley introduced its first direct drive version of the pump at Fire Department Instructors Conference (FDIC) in 2011. It introduced a midship version at the 2012 FDIC in April.
“There is a PTO drive available and we are working on the engine drive version which will be a big thing for industrial users,” Darley said.
The pump can be rated at 2500 to 3000 gpm for NFPA 1901 pumper applications and as a 3,000 to 3,500 gpm pump for ARFF, industrial and fire boat ratings. A two-gear power take-off configuration offers an integrated automatic priming system that can draft from two eight-inch suction hoses at a 10-inch lift in less than 30 seconds.
To generate its maximum flow, the ZS 3000 requires a 500 horsepower engine, Darley said.
“In the industrial world, that is not a problem,” he said. “Any make or model engine that will do 500 horsepower is good with us.”
Design work on the new pump involved developing a transmission capable of handling the increased energy, an automatic priming system and a positive pressure lubrication system that is patient pending, Darley said.
“The new Mega-Trans transmission is not the usual cast iron casing but aluminum to help keep the weight down,” Darley said. “It is a rather large transmission compared to the compact but high torque transmissions we’ve done in the past but it offers the highest torque on the market, surpassing our Magna Trans which is rated at over 1,900 foot pounds .”
Automatic priming is provided by a belt driven primer that utilizes an actuator, he said.
“You push a button at the start to prime it and you can walk away,” Darley said. “If the pump were ever to lose prime, that belt is on a clutch system that would kick in to re-prime it without the operator having to touch it.”
Instead of the standard Darley splash lubrication method where gears carry oil to the highest point, the ZS 3000 uses a small pump driven off the impellor shaft to provide positive pressure lubrication throughout the transmission.
Developing a single impellor that would operate at each of the various ratings desired became the most difficult engineering issue of the entire project, Darley said.
“When you’re sucking that much water, any corner or obstacle can create pockets,” Darley said. “We tried many different styles of impellor. Eventually, the style that worked best is the same twisted vane style we had always used.”
To address various plumbing configurations, the ZS 3000 offers a number of unique manifold designs.
“We’ve got one that looks like a centipede with three six-inch suctions on either side,” Darley said. “We also have a suction T that is an eight-inch manifold. We even have a 12-inch option.”
Developing the ZS 3000 required the construction of a new test room at Darley’s Chippewa Falls, WI, facility.
“We still operate in the old test room,” Darley said. “It’s used everyday, but it only had a 330 horsepower diesel engine that wouldn’t power the new pump.”
The new test room uses two 500 horsepower electric motors. It also provides a larger tank for the ZS 3000 testing.
“Our old test room only had a 20,000 gallon tank available,” Darley said. “With the kind of water the ZS 3000 moves, you can’t keep a tank that size cool. So we built a new test room with a 40,000 gallon tank and state-of-the-art motors and monitoring systems. These improvements mirror our company’s 21st century standing and continued commitment to being on the leading edge of technology available in the pump world.”
The ZS 3000 fills a critical void in the Darley product line, he said.
“A huge need exists for this in the industrial market, the crash truck market and also in marine applications,” Darley said. “A lot of fire boat users are looking for this kind of big water.”