Proper valve maintenance
What is the key to a reliably operating carwash? The answer is often found in a consistent maintenance schedule. Run with assembly line efficiency, carwash systems can come screeching to a halt with just one malfunctioning component. One overlooked cause of the failure might be the small yet powerful solenoid valve.
An electromechanical gatekeeper, the solenoid valve’s purpose among the carwash equipment is critical. Not only does it control the flow of air and water but it also directs the harsher hot waxes and chemical cleaning solutions in a variety of carwash types.
In these sparse economic times, it is good to know that valve maintenance may be easy enough to identify and fix on your own and can be your most cost-efficient choice in the long term. Valves have a basic design, and can sometimes be repaired with common workplace tools. Regular maintenance can increase the valve’s life span and keep your operations running without service interruptions.
Common valve issues
The carwash environment can dictate how hard the valve needs to work, but most valves last an average of one to three years. Ultimately, a valve wears or even breaks down, and can shut off parts of or an entire carwash system.
Maintenance issues vary according to the type of carwash operation — and so should the focus of any inspection. In the carwash, the electromechanical valve is confronted by various pressures. You can pinpoint the problem based on how the valve is used in the operation.
For example, touchless carwash systems employ chemicals to break down dirt and grease, and high-pressure water to rinse off broken-down particles. If the rinse stage does not engage, then you should look first at the water valve. There are three easy steps to disassemble the valve:
- First, remove the nut and washer that secure the coil to the valve’s sleeve. Either a wrench, vice grip or pliers will do.
- Second, unscrew the sleeve from the valve body. In some cases, you can use channel lock (plumber’s) pliers to get a nice grip and not scuff the metal in the process.
- Third, remove plunger and return spring from the sleeve assembly.
Most valve manufacturers have a recommended schedule to inspect different components or systems within the system. Some valve manuals recommend periodically checking and exchanging specific valve parts to extend usability. Generally, carwash owners with high-usage equipment might create a six-month maintenance schedule — about 50,000–80,000 cycles. Valves that operate under less stressful conditions should have annual maintenance checks.
Some internal components — such as the plunger, spring and coil — can fatigue over time. Carwash operators usually focus on the valve’s internal components to improve performance. This is the best decision because replacement of internal parts is more cost effective than buying an entirely new valve. To ease this process, some valve manufacturers sell repair kits that primarily contain the valve’s internal parts:
- Plunger; and
Foreign matter in the sleeve assembly
In one scenario, a malfunctioning valve fails to shift open or close during operation. Debris such as sand or grit may have lodged inside the sleeve assembly. This may have directly affected the ability of the plunger to move within the valve. The plunger’s job is to help the valve actuate mechanically, and allow media such as water or wax to flow through the valve’s orifice.
Periodically, you can clean the inside of the valve with a mild soap solution to remove any foreign matter. To do this, disassemble the valve and look for debris inside both the sleeve and body. During this inspection, check the plunger, springs and the valve’s internal components. Once you have finished cleaning the valve, reassemble and then test it to ensure the issue is resolved.
Keep in mind that foreign matter lodged in the valve is not considered a common occurrence. If you find this a constant problem area, inspect the valve’s environment to find the source of the debris. Clean up the area regularly. If it happens again, you might want to place a filter upstream of the valve to trap those foreign particles.
It is also possible that the valve’s actual coil enclosure design might inadvertently allow moisture to reach the valve’s coil and cause an electrical short. Manufacturers refer to this as coil burnout because the valve’s coil can no longer produce a magnetic field. The valve needs that field, so that the coil can actuate the plunger to open and close the valve’s orifice. At times, it is possible to spot visible markers of coil burnout such as melting on the valve’s exterior. The surest sign, however, is that a valve has ceased to mechanically actuate.
It may be easy to identify coil burnout, but it might require a little detective work to learn why it happened. The shutdown could have occurred because of moisture or possibly a combination of factors such as foreign matter restricting the plunger’s movement and causing excessive in-rush current (i.e. AC voltage applications) overheating the coil.
In coil burnout, you must replace the coil, not necessarily the entire valve. Ideally, it is best to select a coil and coil enclosure that is rated NEMA 4X, a standard set by the Electrical Manufacturers Association. This standard requires a product can provide a degree of protection against splashing water. Unfortunately, a NEMA 4X coil cannot withstand internal condensation or icing. The coil’s design, however, should provide some protection in a “moist environment.”
Corrosion and rust
Corrosion can affect a valve whether it is made of stainless steel or brass. Carwashes that use chemicals and wax should rely on stainless steel valves. This material offers the highest protection against corrosion. Brass, on the other hand, is best when used for water applications. Even with such strong valve compositions, water inside the valve can eventually cause rusting.
Surface rust is a possibility because of the highly moist carwash environment. With a mild soap solution, you can simply rub off the rust. The valve can still function so long as the valve’s metallic parts composition is not compromised.
If the rust penetrates below the valve’s surface, then there is a major problem. Over time, rust can break down the valve even causing the material to become brittle and shatter. Obviously, at this stage, you must replace the valve. In the long run, the best replacement choices are stainless steel valves and NEMA 4X coil enclosures because they have the best track record for resisting rust and corrosion.
Sometimes a valve no longer functions — even with the most diligent of maintenance schedules — and needs to be replaced. Most carwash operators turn to the same manufacturer who sold them the complete carwash system for valves. Little do they realize, there are a host of resources for replacement parts and valves.
Carwash manufacturers often purchase specific parts from other manufacturers. When you purchase parts from your manufacturer, you might be doing so with a considerably high price tag. A more cost-effective solution is to purchase a valve or valve parts directly from the original valve manufacturer. Look for the manufacturer’s name on the valve itself and contact the valve manufacturer’s customer service line. If the manufacturer name is not listed on the valve, then it was probably designed specifically for the carwash manufacturer as a private label.
Another low-cost option is to purchase valves and valve parts from a carwash uperstore — a one-stop shop that warehouses all types of replacement equipment — or from local valve distributors.
Garfield Walker is a product manager for mobile valves at Parker Fluid Control Division in New Britain, CT. Walker has been with the division for 11 years, specializing in automotive, commercial and industrial equipment. He has a Bachelor of Science degree in Industrial Technology from Central Connecticut State University.
For questions, you may call (860) 827-2300