THE SCIENCE OF SPRAY ANGLES
Author: Mike Renner
No one nozzle does it all. Whether it’s a fast rotator, controlled spin, or fixed jetting tool, I need to emphasize how important it is to understand the different spray angles when selecting a nozzle for pipe cleaning. Because trust me, knowing the right angles bring huge benefits. Selecting the right tool for the right application increases productivity, allowing you to you expend less effort, waste less time making you more efficient.
Let’s get right to it…As you know, jets exit from the back and/or side of a nozzle. And those jets are designed to spray at different angles to accomplish several different things.
Why use a nozzle with a 10 degree spray angle: The smaller the degree/spray angle, the more forward thrust you get from the tool. And more debris gets pushed backwards. The other side of the coin, it takes the water longer to go from the nozzle to the wall of the pipe. Here’s an example… you’re using a nozzle with a lower degree spray angles to clean grease out of a pipe. You have great forward thrust but a tool with this spray angle will not clean much of the wall of the pipe.
For general cleaning it is recommended to use a multiple degree nozzle. Generally a combination of 10 and 30 degrees. 10 degrees gives you the forward thrust and the push to move material back to the manhole, and the 30 degree nozzle allows the spray to blast material off the side of the pipe.
When you need more cleaning especially on the pipe walls, then 90 degree jets are the go to. 90 degree jets are the best cleaning degree as it scours the pipe walls and breaks up grease into manageable sizes. The downside to 90 degree jets is there is no forward thrust.
When selecting a nozzle for your next job, then you need to ask yourself these questions:
What are we using the tool for?
A fixed jetting nozzle with multiple spray angles (generally 10 and 30) … Great for general maintenance cleaning!
Have blockages? Go for a penetrating nozzle that’s pointy or chisel shaped with forward jets at low angles and rear jets for thrust
Cut grease or roots with a rotating nozzle with 90 DEGREE spray and 30 or 45 degree rear jets for thrust
The lesson in all of this… knowing what you’re getting into and knowing the degree of the nozzle and how that affects you is really what’s going to help you when you’re out in the field.