The Action of Spray Nozzles and their Uses

If, as a child, your home lacked a swimming pool, you probably kept cool during the summer months by spraying yourself with a garden hose. Perhaps, when getting together with siblings or friends, you enjoyed some fun and games by turning the hose on each other. Alternatively, you may have been more industrious and used it to water the flower beds or clean the family car. Either way, however unwittingly, there’s a good chance you discovered how spray nozzles work.

When garden centres were still a rarity and lacked the wide range of garden tools and accessories we enjoy today, a hose was simply a long rubber tube. You forced one end over the end of the tap, turned it on,

and water emerged from the other end at a rate determined by your proximity to the source. However, by squeezing the hose’s outlet, the restriction led to increased water pressure, generating a fine jet and propelling it much further. Today, a hose purchase generally includes a tailored connector to attach the tap and a plastic or metal spray nozzle to control the width and reach of the ejection stream.

Two structural attributes combine to determine the behaviour of liquids in a pipe; the diameter of the tube and the design of its outlet. In practice, these design features will, in turn, affect two physical properties that relate to fluid dynamics. These are the liquid’s flow rate and its hydrostatic pressure, and the two are inversely proportional. In simple terms, that means any decrease in the flow rate will automatically lead to increased fluid pressure and vice versa.

That said, the applications for spray nozzles are numerous and far more demanding than regulating a garden hose. When constricting the outlet of a pipe to mere thousandths of a centimetre, it becomes possible to generate fluid pressures as high as 50 000 to 90 000 PSI. Such extreme pressures are typical of those necessary for waterjet cutting tools that can slice through a steel girder or granite slab without overheating or losing their edge.

However, most of the equipment that depends on the high pressures produced by spray nozzles is for use in heavy-duty cleaning tasks. The more challenging the task, the higher the pressure required. In addition to the automated drive-through car washing facilities found at selected filling stations, entrepreneurs can often be seen using a handheld pressure washer to perform a manual service. For tasks like cleaning mining and earthmoving equipment, there are correspondingly more powerful tools.

For a wide range of quality pressure pumps, spray nozzles and related accessories for cleaning and other applications, contact Bestline Manufacturing.