Spray Nozzles, Part II:
You Can Make Them Last Longer. Here’s How
By Jerry Hagers

In last month’s issue of Auto Laundry News, we discussed the importance of spray nozzles in your car wash. We looked at ways to indentify worn nozzles, learned about the causes of nozzle problems, and provided a checklist for the effective monitoring and maintenance of nozzles in a car wash operation. This month, we conclude our discussion with a review of proper nozzle material selection, and an overview of techniques to extend spray nozzle life.

CHOOSING PROPER NOZZLE MATERIALS

When you replace old, worn nozzles, it’s vital to select new nozzles made of materials that are appropriate for your situation.

Replacing your old spray nozzles with the very same type may not be the best way to go. Obviously any new spray nozzle is superior to a worn spray nozzle, but your situation may call for replacing, say, regular stainless-steel nozzles with ones made of hardened stainless steel — featuring ceramic orifices — that are better suited to handle the cleaning chemicals that you routinely spray.

Hardened stainless steel nozzles will typically last two times longer than regular stainless steel nozzles in high-pressure applications.

To determine whether you should consider a different material for your spray nozzles, spray tips and/or orifice inserts, take a moment to review the abrasion ratio chart below.

In addition to abrasion resistance, you need to consider a nozzle’s corrosion resistance. The rate of chemical corrosion on a spray nozzle depends on several factors, including the corrosive properties of the liquid being sprayed, its concentration in the solution, its temperature, and the properties of the spray nozzle material.

A reputable spray-nozzle company can analyze these factors for you and offer an appropriate recommendation. It should also offer a selection of high-quality spray nozzles in a variety of materials — and be willing to design custom spray nozzles for you if needed.

EXTEND SPRAY NOZZLE LIFE

Once you have selected the proper nozzles, made of the proper materials, there are some techniques you can employ to prolong their useful life:

1. Decrease spraying pressure. Where circumstances permit, decreasing the pressure — which will slow the liquid velocity through the orifice — may help reduce the wear and corrosion rate.
2. Reduce the quantity of abrasive particles, or the concentration of corrosive chemicals. In some applications, you can reduce the amount of abrasive particles in the feed liquid, and/or change the size and shape of the particles to reduce wear effects. Also, the corrosive activity of a solution can occasionally be reduced by using different concentrations or temperatures, depending on the specific chemicals involved.
3. Add line strainers, or change to spray nozzles with built-in strainers. Orifice deterioration and clogging is typically caused by solid dirt particles in the sprayed liquid and is particularly common in systems using continuous spray water re-circulation. Strainers or spray nozzles with built-in strainers are recommended, with a screen mesh size chosen to trap larger particles and prevent debris from entering the spray nozzle orifice or vane.
4. Be careful when cleaning spray nozzles. Remember, spray nozzles are precision instruments. Cleaning should be done regularly, but very carefully, with materials that are much softer than the spray-nozzle orifice surface. Use plastic bristle brushes and wooden or plastic probes. Never use wire brushes, pocketknives, or welder’s tip cleaning rasps. It is easy to damage the critical orifice shape (or size) and end up with distorted spray patterns or excess flow. If you are faced with a stubborn clogging problem, try soaking the orifice in a non-corrosive cleaning chemical to soften or dissolve the clogging substance.

CHOOSE A TRUE PARTNER

Be sure your nozzle manufacturer isn’t just a “vendor.” If all you’re getting is nozzles, you aren’t receiving full value for your money.

A top manufacturer serves as a genuine partner by offering system audits, spray-nozzle-maintenance workshops, on-site inspections, specific recommendations and valuable training for your staff.

In addition, your manufacturer should have the capacity to test and evaluate spray nozzles using state-of-the-art equipment to help establish baseline performance measures that will guide your cleaning, maintenance, and repair schedules. This can minimize downtime significantly, and help avoid quality control issues through timely spray nozzle replacement.

An intelligent spray system optimization program will deliver significant savings in time, money, and efficiency. Contact your nozzle manufacturer and begin your optimization program today. Your car wash customers will thank you — and your bank account will soon reflect the wisdom of taking action.

Jerry Hagers is product specialist at Spraying Systems Co. in Wheaton, IL. He can be reached via e-mail at jerry.hagers@spray.com or by phone at (630) 665-5000. For a free copy of the Spray Optimization Handbook, call 1-800-95-SPRAY.