Many contractors and municipal operators are investing in sewer cleaner trucks equipped with eco-friendly water recycling systems that facilitate cleaning more line in less time. However, few understand that even high-quality “standard” jetting nozzles can become clogged when recycled water is not sufficiently filtered. This results in excessive downtime since operators must repeatedly halt production to clean the nozzles, a process that negates some of the productivity gained from the vehicle itself.
Instead, a better solution is to use specially designed nozzles that allow recycled water with fine particulates to efficiently flow through without clogging. By doing so, operators can clean 3-5 times more line than standard, up to 12,000 feet per day.
“If the recycling system is not working properly and keeping the water clean, some particulates will enter the channels of the nozzle. If the orifice is too small or imprecisely designed, then the material accumulates and plugs it so you are constantly trying to achieve full flow again. This is why you need to use special nozzles that allow complete flow through the orifice [even when particulates are present],” said Dan Story, an experienced trainer and Operations Manager at KEG Technologies, a manufacturer of sewer and storm line products including Tier 1 to Tier 3 nozzles, chain cutters, floor cleaners and camera nozzle systems.
According to Story, one indication that a nozzle has become clogged is a noticeable increase in pressure and a corresponding reduction in the RPMs of the equipment.
The short-term solution is to take the nozzle apart and thoroughly rinse it to clear out any accumulated debris, followed by reassembly. The process typically takes 15 to 30 minutes, during which the work crew is not actively jetting.
In contrast, the long-term solution is to utilize special nozzles that are designed not to clog when used with recycled water trucks along with routine system cleaning.
“In a regular truck, the national average of jetted line is about 2,500 feet if operators take the time to really clean without having to make extra passes. With nozzles specifically designed for recycled water trucks, up to 12,000 feet of line can be jetted and thoroughly cleaned in a single day, making subsequent passes unnecessary,” said Story.
He explained that even the most efficient, well-designed Tier 3 nozzles have smooth internal channels that direct the water precisely based on complex fluid dynamics. Excessive particulates in recycled water create obstructions.
“As the material floating through the recycled water passes through traditional nozzles, it tends to ‘ball up’ until it creates a blockage,” said Story.
To address this concern, KEG Technologies designed specialized versions of many of their popular nozzles and cutters that allow particulates to pass through without creating an obstruction. According to Story, the nozzles include those used for sewer cleaning, floor cleaning, traction and cutting.
“With the recycled water nozzles, the water must flow smoothly and without obstruction before entering the jets, which can cause some turbulence that leads to particulate accumulating. Instead, the pathway is curved to keep the water flowing and keep the jets from being blocked,” said Story.
The use of a non-clogging nozzle essentially unlocks the true potential of using recycled water trucks for sewer jetting. The approach facilitates up to 5 more hours of jetting per day since the work crew does not need to retrieve more water every 15-20 minutes. Operators start with a fresh tank of water and jet all day, maximizing productivity. This saves water, fuel and vehicle/machine wear.
Additionally, operators do not even need to use potable water to jet. Instead, they can use existing water in the manhole, further conserving more costly drinking water.
Among its offerings for recycled water trucks, KEG Technologies has developed several unique high-performance nozzles. One example of a recycled water truck nozzle is a version of the DUCE, a vibrating rotational nozzle that is engineered to remove hardened deposits from the pipe wall or floor. The nozzle provides a tight water pattern for intense, directed cleaning and propulsion. Any clogging only serves to weaken the hydro-flushing action.
The OEM also offers a recycled water truck version of its SuperNova 4000 cutter with reinforced chains to efficiently eliminate deposits and incrustations of all kinds such as lime, concrete and extensive root growth in pipes and sewers. The cutter is adjustable for pipes from six inches all the way up to 48-inch pipe.
Story adds that a version of the SuperNova 4000 cutter nozzle is designed to be particularly helpful for recycled water use because it does not run on a shaft in bushings that can cause “lock down” when particulates get lodged in between. Without the shaft, the nozzle internals run smoothly and reliably, enabling greater productivity.
As an industry expert and trainer, Story is seeing contractors and municipalities increasingly move towards using recycled water trucks along with special nozzles despite the initial higher cost of equipment once they have been properly informed and understand the value.
“When you can potentially triple or quadruple the amount of pipe that you can clean per day with recycled water trucks and nozzles designed not to clog, it’s a no-brainer to use the combination. The far greater productivity along with savings in labor, water, fuel and vehicle wear provides exceptionally fast ROI,” concluded Story.
