I frequently get phone calls or emails with questions about the nozzle study conducted at my department. Recently a firefighter looking for some assistance took me down a line of issues and his attempted solutions which sounded very familiar.
Let us begin with Integrated tips and break away nozzles. Call it what it is; compromise threaded on to compromise for the sake of compromising. An integrated tip can be a miserable smooth bore nozzle. It works, but the stream is very poor due to the reduced distance allowed for shaping within the shut off.
A “break away” nozzle is just a nozzle. It was designed and tested to be screwed on to a shut off and supplied with the appropriate sized waterway typically 1 ¼” to 1 3/8” in the 1 ½” shut off and 2 ¼ to 2” in the 2 ½” shut off. The “break away” nozzle is not designed, tested and rated with a choked down supply of a 15/16” or 7/8” integrated tip. I fully understand the desire to make everyone happy; I just don’t believe it should come at the cost of reducing everyone’s effectiveness.
Stream Shapers – I believe it was Chief McGrail that brought it to our attention when we were doing our nozzle study. We were asking him about the use of stream shapers and he made a simple statement that a properly pumped smooth bore tip should have no need for a stream shaper. We knew our pressures were correct; we had several different tip styles and yet the streams were still poor quality. That is when he told us to check our balls........ the ball valves that is
At some point in peak of the automatic/100 PSI nozzle frenzy, manufactures began to change out the classic ball valve with a “split ball”. The theory behind this gimmick or marketing tool or pointless technological advance change was to assist the shut off operator with opening and closing the bale against the high pressures. As soon as the “split ball” moves the “split” allows for water to act on it and push in the desired direction. In the setting of a fog nozzle the affects of the split on stream are not noticed. When a smooth bore tip is placed on a shut off with a split ball the stream destruction begins. The split results in a turbulent waterway as the supply passes through the shut off. To demonstrate the differences we attached a 15/16” slug tip to a shut off with a split ball and one with a solid ball. You can see clearly the difference in stream quality. The last picture is of a standard 15/16” smooth bore tip at proper pressure with a solid ball valve, a thing of beauty.
Tested Set Up 15/16″ Slug Tip @ 50 PSI
In conclusion, I personally prefer a smooth bore nozzle for interior fire attack. I am not a fanatic which opposes all fogs. I believe that researching and providing options will always further your cause. In regards to handline nozzles my cause is a low pressure, high volume line. If your department insists on providing a fog option please look into a fog nozzle with a pressure/volume combination which matches your selected smooth bores. There are 185 gpm at 50 psi, 250 gpm at 50 psi and 325 at 50 psi fog nozzles available from many manufactures. This pressure/volume match helps keep pump discharge pressures consistent for operators and ensures that lines are being followed up by lines of equal or greater volume. Below is a more comprehensive video demonstration of the effects of a change in ball valve has on your stream quality.