After reading your pro/con debate on big pumps, I agree with Gary Handwerk’s reasoning for selecting a 1,500 gpm, or larger, pump. As Handwerk notes, the 1,500, 1,750 and 2,000 gpm pumps are the same pump they are just tested differently.
Pumps rated at 1,750 and 2,000 gpm require two sets of hard sleeves (one out each side) to pass an annual service test.
Most companies do not have the additional equipment or a location to do this. The chances of finding a location and actually using sleeves out of both sides at a fire is probably slim. Even if they do have the equipment and location, a 1,500 gpm pumper with equivalent horsepower and the same hose layout will pump the same amount of water.
With hydrant work, it is simply a matter of how much water will fit through the pump housing and there is no performance difference among the large body pumps.
When my fire department specifies a pump in a new engine, we have the pump tested and certified by the manufacturer for 1,500 and 2,000 gpm, then have the Underwriters Laboratories certify it at 1,500 gpm.
When performing the annual service test, we only need to use one set of sleeves. We do carry enough equipment for drafting operations with sleeves out both sides if needed, and have pumped in excess of 2,600 gpm from draft.
Plan For Future Needs
For some departments it is easy to dismiss the value of big pumps simply by saying “we don’t have an adequate water supply in our town to support a 1,500 gpm pump.” That may change over the life of the pump, and with the ever increasing mutual aid responses you may find yourself working in a relay or as a supply pumper well outside your local area.
A 1,500 gpm pump gives you the flexibility to work within your local water system limitations and still allows you to deliver in excess of 2,000 gpm given the proper equipment and water source.
One thing I do agree with Michael Farrell on is “adopting the whole package to fully appreciate the potential flow capabilities” of the pump.
Make sure you specify proper size large diameter hose (LDH) discharges to get the water out of the pump and take a look at the actual flow capabilities of your next intake valve. Some are restrictive while others have very little loss even up to 1,500 gpm. Ask your sales representative for demo units to test before you buy.
The size of your supply hose is also a major component when trying to deliver the gpm you are pumping. In a typical 1,000-foot relay, 4-inch hose is limited to about 900 gpm. Then you start running into the NFPA limit of 185 pounds on supply hose given a normal residual of 20 to 25 pounds. A 5-inch line can provide 1,500 gpm over the same distance with approximately the same discharge pressure.
The 1,500 gpm pump appears to be the most versatile pump today and unless you need a higher rating for ISO, you are simply paying more for a number.
Editor’s note: Daniel Supplee has been a firefighter and a fire officer with the Oreland Volunteer Fire Company, Oreland, Pa., for 38 years, serving as its chief for the past 15 years. He is vice president of a family-owned and operated fire pump repair and testing company, Supplee Bros. Inc. He is also a senior fire pump operations and hydraulics instructor for the state and county. He was instrumental in developing the Montgomery County LDH Task Force.