When utilizing stacked tips or a smooth bore tip on a deluge gun or ladder pipe, a stream shaper is a critical piece of the equation for having an effective stream. Sharp bends in master stream devices will have negative consequences on the flow of water, creating turbulence that must be redirected to laminar flow to exit a smooth bore tip properly. Without a stream shaper, the flow of water is unable to become laminar, and it will cross over itself as it exits the discharge orifice. This will lead to a terribly broken up stream with a wide footprint and little to no accuracy.

First, its important to note that there are two basic categories of monitors that are found on most apparatus when used as either wagon or ladder pipes. The monitors can be simply classified by their outlet size and rated flow. They are typically ones up to 1250 GPM with a 2 1/2” outlet and up to 2000 GPM with a 3 1/2” outlet. While there may be some others mixed in, these two sizes are the predominant sizes/ratings. The size of the outlet on the monitor will drive the choice of tips selected. There are a few options, which should be carefully compared by researching the manufacturers literature.

For 2 1/2” outlet monitors (rated up to 1250 GPM) there are three common tip options. A single “long barrel” tip, a triple stack tip set and a quad stack tip set. In the 2 1/2” diameter category you have the choice between a short (between 4” to 6” long) or long (usually around 10” long) stream shaper. The choice of which to use is often dependent on the nested position of the pipe or its travel “scrub area”. You should be able to operate the device for as wide a range of motion possible. It may be necessary to use a short stream shaper to reduce the overall length to work around the rig body configuration.

For 3 1/2” outlet monitors (rated up to 2000 GPM), there are also typically these same two options (approx 4” and 10” long) although due to space, the longer shaper is rather impractical if using stacked tip sets on an aerial. One issue with the larger outlet monitors is that the longer stream shaper will often be furnished with 2 1/2” end threads to attach the tips to, so if you desire the higher flowing tips (larger than 2” orifice) you will be forced to use the shorter length shaper. There are variations of shaper inlet and outlet configurations, so you must consult the manufacturer to assure that they offer your desired inlet and outlet options.

2 1/2” Stacked tip sets come in either triple or quad configurations. The quad stack is the most common, with tips of 1 3/8”, 1 1/2”, 1 3/4” and 2” set with flows of roughly 500, 600, 800 and 1000 GPM respectively. The actual length of the tips varies by brand, with the longer ones most likely to offer a slightly improved stream.

3 1/2” stacked tip sets are available in two common configurations. The 2”, 2 1/4” and 2 1/2” set provides a leading tip with a plain end and no threads. It offers flows of roughly 1000, 1300 and 1600 GPM respectively at 80 PSI. The 2 1/4”, 2 1/2” and 2 3/4” set offers “leader threads” on the end, allowing a smaller tip or set of tips to be attached. This configuration offers flows of roughly 300, 1600 and 2000 GPM respectively at 80 PSI.

It would take consideration of any number of factors to decide which set of tips to attach to the monitor, but I will offer that as you increase the tip size beyond 1/2 of the inlet size the stream will show some signs of degradation. While this will not necessarily have a major impact on operations, and a laser sharp stream isn't a necessity, it is a point worth noting and it is particularly true with the largest tip of any stacked set. Consider trying the 1 1/2” tip on 2 1/2” outlet monitors and the 1 3/4” or 2” tip on 3 1/2” outlet monitors as a fair choice for good flow with reasonable stream quality.

There are no shortage of choices in tips and shapers, but one thing is a definite. You need the shaper to provide a decent quality stream. Here are a few photos to show the comparison of the streams with and without a shaper.

A 1 3/8” tip is shown on the 3 1/2” outlet ladder pipe in the photo below. The flow is right around 500 GPM at 80 PSI to show the impact of the stream shaper. I chose this tip, as it is the smallest tip on most quad stack sets and the extra length will often aid in smoothing the water flow in conjunction with the stream shaper. To address the extra length and its impact without a stream shaper, the photo speaks greater than words.

A 2 1/4” tip is shown in the photo below, as it represents the “leading tip” on one of the triple stacked sets available for 3 1/2” outlet monitors. The flow and pressure are roughly 1300 GPM at 80 PSI

In conclusion, a stream shaper is an absolute must when using smooth bore tips on master streams of any type. Longer shapers will add some improvement, but a short one is certainly better than none.