We have discussed the importance of apparatus positioning before when it comes to drafting. While digging through some older photos last week we found a couple of photos of pumpers drafting that we thought we would share. It is important to remember that unless you specify anything different, your pumper is going to come from the manufacturer with two (2) 10-ft lengths of suction hose sized to fit your pump's primary suction inlets.

We are an advocate of rural pumpers carrying more than 20 feet of suction for the purposes of, 1) reaching water sources that are farther than 20 feet away from where the pumper can park; and 2) drafting using dual suctions so that maximum pump performance can be achieved.

Keep in mind however that "lift" is perhaps the greatest challenge for a centrifugal fire pump: there is little we can do to compensate for that lift short of placing the pump as close to the water's surface as possible. This of course is where apparatus positioning comes in. There will be those times when an operator cannot compensate for lift. That is fine - just understand that as lift increases - pump performance decreases. One example that often is used to note reduced performance due to lift is: A 1,000 gpm pump drafting through 5" suction hose at 10-feet can only pump 590 gpm at 20-feet! While these values may not be exact - they are very representative of the effects of vertical distance on a fire pump.

The good news is that horizontal runs of suction hose are not as problematic to pump capacity. While suction hose does have friction loss associated with it, much longer horizontal runs can achieve higher flows than had that same run been vertical. Again - a good reason to carry more than 20-ft of suction hose.