When trying to figure out the best nozzle for a particular cleaning application, you need to ask yourself, “What is the nozzle going to do?”  If the answer to that question involves washing or rinsing bottles, kegs or barrels, small storage tanks, plastic crates or cleaning machines in place, then a rotating nozzle might be for you.

Another option might be a cluster of fixed nozzles, but in that case you’re paying for the cluster assembly as well as the individual nozzles. Once installed, a cluster gives you a less-concentrated spray over a wider target area, potentially wasting fluid and getting a less-than-advantageous result.

A rotating nozzle, such as those in Bex’s TWK Series, sprays a small portion of a bottle or tank at any one instance. You’re taking a concentrated spray and moving it around, providing more impact on the walls than you would get from a cluster spraying the whole tank at once. There’s very little that a cluster can do for you that a properly sized rotating nozzle can’t.

Make Sure the Application Fits the Nozzle

The energy required to spin a self-rotating nozzle comes from the energy in the pumped fluid. Therefore, a self-rotating nozzle isn’t the best fit for every application. If the fluid is being pumped through the nozzle at more than 100 psi, you start getting unwanted wear on the ball as it rotates around the stem.

Applications where you need a large throw, say in a 10-30 ft diameter tank, might be better served by a motor-driven rotating nozzle. With a motor-driven nozzle, all of the energy in the pumped fluid is directed at the target. There is no decrease in energy from having to spin the nozzle as the rotational energy is provided by the motor.

Motor-driven nozzles, however, are more difficult to install and maintain, and can be significantly more than a TWK rotating nozzle. Self-rotating nozzles also may be preferable to an expensive motor-driven system in applications where the cleansing action is more dependent on a chemical reaction than the impact of the spray.

Life Expectancy

Rotating nozzles in cleaning applications are used to spray anything from pure water to water mixed with detergent or acidic/caustic cleaning fluids. The cleanliness and abrasiveness of the fluid being sprayed is one of many factors related to a rotating nozzle’s life expectancy.

Other factors include duration of continuous use and the pressure being used. High pressure will make the ball spin faster and cause more abrasion where the ball meets the stem.

Slots vs Holes

A Bex TWK rotating nozzle has two slots rather than many round holes (typically eight) through which fluid is sprayed. Two slots give the nozzle better distribution because the slots create a fan-type spray. Holes create solid streams of liquid. The solid streams don’t do a good job of filling in the spaces between each stream. Also for nozzles of equal spray capacity two slots create larger droplets than eight round holes as each individual slot is larger than each hole by a factor of four. Larger droplets do not slow down as much when they leave the nozzle and hit the air. As a result they carry farther and impact harder on the target.

Eight smaller holes will plug more easily than two larger slots due to the smaller area of the holes. Also It’s difficult to plug an entire slot. You’d have to have a piece of debris with a shape that conforms to the shape of the slot and that’s very unlikely. More likely is that sediment will begin to gather at the ends of the slots and fluid rushing by will knock the sediment away. This effect, and the weeping at the top and bottom of the rotating ball, gives the TWK rotating nozzle its self-cleaning feature.

Maintenance

Once a rotating nozzle is selected, installed, and operating, you want to make sure it's always giving its best performance. Many companies have a regular maintenance schedule. They may take their machines down once a week for minor maintenance and every three or four months for major maintenance. In a program like this, it’s good to check the nozzles every week until you’re satisfied that they’re performing over the long term. Then, check them every quarter or every six months.

Since it’s difficult to determine a nozzle’s performance because you’re not seeing the spray, other methods must be used to check for blockages and wear. The pressure gauge is your best friend in this case. If the pressure in your feed pipe is going up, that’s telling you that the nozzle is probably plugged. If the pressure in the pipe is going down, then the nozzle might be worn and leaking. There could also be a leak elsewhere in the system, but the nozzle is one of the first places to look.