Double Venturi Blasting Nozzles 

Blasting Nozzles generally come in two basic shapes: straight bore and venturi, with several variations of venturi nozzles.

Venturi nozzles are commonly divided into single-inlet venturi and double-inlet venturi nozzle.

The single venturi nozzle is a conventional venturi nozzle. It is designed in a long tapered converging entry, with a short flat straight section, followed by a long diverging end that widens as you reach the exit end of the nozzle. This shape is designed to produce an effect that greatly accelerates the airflow and particles and evenly distributes the abrasive over the entire blast pattern, yielding about a 40% greater production rate than the straight bore nozzle.

The double venturi nozzle can be thought of as two nozzles in series with a gap and holes in between to allow the insertion of atmospheric air into the downstream segment of the nozzle. The exit end is also wider than a standard venture blast nozzle. Double venturi nozzles offer around a 35% larger blast pattern than a conventional venturi blast nozzle with only a slight loss in abrasive velocity. By providing a large blast pattern, the abrasive blast nozzle enables increased abrasive blast efficiency. It is ideal for jobs where a wider blasting pattern is needed.

In BSTEC, you can find many types of double venturi nozzles.

1.     Classified by Nozzle Liner Material

• Silicon Carbide Double Venturi Nozzle: the service life and durability are similar to tungsten carbide, but only about one-third the weight of tungsten carbide nozzles. Silicon carbide nozzles are an excellent choice when operators are on the job for long periods and prefer lightweight nozzles.

• Boron Carbide Double Venturi Nozzle: the longest-lasting material used for blast nozzles. It outwears tungsten carbide by five to ten times and silicon carbide by two to three times when aggressive abrasives are used. Boron carbide nozzle is ideal for aggressive abrasives such as aluminum oxide and selected mineral aggregates when rough handling can be avoided. 

2.    Classified by Thread Type

• Coarse (Contractor) Thread: Industry-standard thread at 4½ threads per inch (TPI) (114mm), this style greatly reduces the chance of cross-threading and is much easier to install.

• Fine Thread (NPSM Thread): The National Standard Free-Fitting Straight Mechanical Pipe Thread (NPSM) is the Industry standard straight thread used widely in North America.

3.    Classified by Nozzle Jacket

• Aluminum Jacket: offer a very high level of protection against impact damage in lightweight.

• Steel Jacket: offer a very high level of protection against impact damage in heavyweight.