Relay Pump Operations: Who Says It's Just for the Long Lay?
This article is going to present statistics from several flow tests showing the advantage of setting up relay pump operations on short LDH supply line evolutions. By now you are probably thinking why set up this relay pump operation when additional supply lines from additional engines can be laid instead, allowing multiple pumpers to help to assist in delivering the water versus one. There are several reasons that might require a single engine company to produce maximum flows.
It may be that the area the water needs to be delivered from is only big enough for a single engine company to work from such as, a cul-de-sac, a parking lot full of cars, or an alley just to name a few. What if, for whatever reason, additional engine companies are not responding or extremely delayed? Well, guess what, the little engine company that could, is going to have to pump its little heart out. This is where short relay pump operations can be a great benefit.
|Sparks Ladder 31 is in the background sitting on a hydrant 500 feet away in a short relay pump operation.||This evolution has dual supply lines, a 5" and a 3". The 3" line brought in an additional 600 GPM.|
Some of the tests involved the use of a hydrant relay appliance. The hydrant relay valve (HRV) is a piece of equipment that is connected to the hydrant and the beginning of the supply hose. It allows the initial supply line to be laid and charged, utilizing hydrant pressure only. If more water/pressure is needed, a second engine company can connect into the HRV at the hydrant and switch over a water control valve to the relay pump mode pumping back into the supply line without shutting the hydrant down.