Know Your Nozzles

By Clemco E-Update October on Oct 18th 2019

Know Your Nozzles: Blast Nozzle Basics

Tips to Help You Effectively Use and Choose Blast Nozzles

Tip 1—Nozzles Wear Out: Replace Them

It’s unavoidable. Just as abrasives change the surface of an object being blasted, abrasives wear down the orifice of a nozzle as they pass through it.

And as the orifice of a nozzle wears, and then expands, it needs more air volume to maintain the desired air pressure. For example, a nozzle with a 3/8” (9.5 mm) orifice operating at 100 psi requires about 200 cfm of air. If the orifice enlarges by 1/16” (1.5 mm), the air requirement increases to more than 250 cfm—a 25% increase.

Aside from increasing air use, this inevitable wear affects a nozzle’s service life, performance—and safety. Any nozzle orifice worn beyond 1/16” its original size could cause injury if the liner fails. So although it may save money in the short run to keep using worn nozzles, in the long run it is a wise economic and safety investment to replace a nozzle after its orifice wears beyond 1/16” its original size.

Tip 2—Service Life: Carbide-Lined Nozzles

See the chart below to compare estimated service lives of the three most popular types of carbide-lined nozzles: tungsten, silicon, and boron. Carbide-lined nozzles are the most popular choice for the majority of blasting applications due to their long life, even though carbide nozzle liners tend to be brittle. To protect against this brittleness, Clemco nozzle liners are encased in a jacket, usually made from metal, or rubber.

Carbide-Lined Nozzles Estimated Service Life (in hours)