How to choose the right nozzle for the job?
Choosing the right nozzle for the job is a science. There are a variety of models to choose from where the number of water jets and their angles vary. The internal design of the flushing nozzle, that is, the passages where the water run through the nozzle body before the water flows out through the jet inserts. The internal design of a cleaning nozzle affects highly how effectively the nozzle transports the waterpower from the hose.
We want to give some tips on how to think about choosing the best nozzle for the job.
In the video, you see a comparison with a "normal" sewer nozzle with many water jets, compared to our BL Swiper® with few water jets.
The number of water jets
What are the advantages and disadvantages of many outgoing water jets compared to fewer jets in a nozzle?
The number of times we divide the water flow rate available, the thinner each water jet will be.
A good rule of thumb is to choose a nozzle with fewer water jets to make them as thick and powerful as possible. The disadvantage of fewer jets is that they can create "strips" in the pipe. This usually happens when the material in the pipe is on the sides and is hard packed. If there is any drainage material in pipe, such as loose sand or gravel, these types of nozzles may also create a "strip effect".
• Fewer jets are always more effective when moving material in pipe, compared to many smaller water jets.
• If pipe needs to be cleaned all around (360˚), more water jets are preferred.
• To be able to adapt to every project, you should always have both options of nozzles available on the jetting truck.
Angles of the water jets
How should one think about the angles of the water jets coming out of the nozzle?
To simplify, we divide the angles of the water jets into three different categories.
Cleaning nozzles with 0–12-degree rear thrusting jets are designed to move material in the pipe. The lower the angle, the more efficiently the material will be transported in the pipe.
At a lower angle, the distance from when the water leaves the nozzle until it reaches the pipe is longer. This is where the inner design of the cleaning nozzle comes in. An optimal water-conducting design keeps the jets together significantly longer behind the nozzle and therefore gives the opportunity to work at lower jet angles and still clean all the way out to the pipe wall. Nozzles with poor internal design will not do the job in larger pipes.
Cleaning nozzles with thrusting rear jets in an angle between13-30 degrees are normally call universal cleaning nozzles. Nozzles in this category often have more rear thrusting jets in different angles. They normally can move material in pipe if there is not too much and are quite efficient. They are also able to clean the inner pipe wall effectively if it is not too hard or greasy material.
Nozzles with thrusting rear jets in an angle between 31-90 degrees is for pure pipe wall washing or descaling. Rotary nozzles are widely used in this nozzle category, but there are also Bomb or Grenade type of nozzles where 50 % of the water jets have an angle of up to 45 degrees and the jet inserts are of the type of fan jets intended for pipe wall cleaning or descaling. These types of nozzles are not designed to move large amounts of material in pipe. If the pipe contains a large amount of material, start by cleaning out the material with a more efficient 0–12-degree cleaning nozzle. After the cleaning is done, run with the 31-90 degree “pipe wall washing nozzle”.
Take care of your water pressure and your wallet
For the nozzle to work effectively, it is important to choose a nozzle that has as little internal turbulence as possible. Turbulence inside a cleaning nozzle creates pressure losses. This means losses of energy, energy for which you paid dearly (diesel/water). The turbulence also produces jets of water with significantly less power. Turbulent water also results in a shorter length of the water jets, which makes the nozzle work inefficiently.
The less turbulence the internal design of the nozzle creates, the more efficient a nozzle is. Then you do not have to throttle up the jetting unit as hard and thus reduce wear and tear on the pump, driveline, and clutches, while saving a lot of diesel, water, and money. This is a No Brainer.