Depending on the quantity of solution flowing, the length and diameter of the hoseline being used, the nozzle pressure required, and the elevation, all together determine just how far you can stretch a line. The key is not exceeding the 65% of the rated inlet pressure. Remember, as with any appliance, each manufacturer has their own rules and guidelines, so make sure you know the specific details of your own equipment. Take a look at the individual specifications of your equipment. The web sites at the end of the first part in this series have a lot of detail that can guide you in your fireground decision-making.
A valuable attribute of the portable eductor is that it can be placed closer to the scene in situations that preclude the engine from getting close. Take for example a fire at a dock of private yachts and vessels. A fuel leak has ignited and multiple small boats are presenting an exposure problem. The fuel is burning on the surface of the water. The engine stops 500 feet from the fire and is unable to get any closer. This is certainly too far to use 1¾” hose to get a foam line in operation, so what can we do?
- The engine stretches 400 feet of 3” hose (with 2½” couplings) to a 2 ½” x 1½”reducer
- Then a portable eductor with 1½” threads is placed in the stretch
- From the eductor another 150’ of 1¾” is stretched with the appropriate nozzle
- The engine discharge pressure is about 210 PSI (the 10 PSI compensates for the friction loss in the 3” hose going to the eductor)
- The eductor now has an inlet pressure of 200 PSI
- The eductor we’re using in this scenario is rated at 125 GPM
- Foam solution is then delivered via the 1¾” hose line to the vessel on fire
As you can see, the portable eductor has a lot of versatility. It is a relatively inexpensive and effective way to get a basic foam line into operation.
This is just one scenario for the use of the portable eductor. We’ll use more scenario-based examples as the articles continue, but this gives the reader an idea of the opportunities we have to get a foam line in operation a lengthy distance from the engine company. Remember though, where the eductor is set up is also where the foam concentrate has to be delivered. This requires the necessary logistics.
Until next time we meet, take a look at your portable inline eductors and see if you can answer these simple questions:
- What is the eductor rated at? 60 GPM? 95 GPM? 125 GPM?
- What is the required inlet pressure? 200 PSI? Less than 200 PSI?
- What percentage does the metering valve have listed on it? 1%, 3%, 6%?
- Does the end of the pick-up tube have a small screen on it or not?
ARMAND F. GUZZI JR. has been a member of the fire service since 1987. He is a career fire lieutenant with the City of Long Branch, NJ, Fire Department and is the deputy director of the Monmouth County, NJ, Fire Academy where he has taught for over 20 years. He has a masters degree in management and undergraduate degrees in fire science, education, and business administration. View all of Armand's articles here. He can be reached via e-mail at email@example.com or firstname.lastname@example.org.