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Cleaning Equipment Maintenance

By Ed Sunkin

The saying, "An ounce of prevention is worth a pound of cure," definitely holds true when it comes to the operation of cleaning equipment in rebuilding shops.

According to David Zehren, product manager, stationary equipment for Georg Fischer Disa Goff, Inc., Seminole, OK, routine maintenance of cleaning equipment impacts all rebuilders, no matter how large or small. "The issue of lost production and down time from neglected equipment is a subject that no rebuilder can afford to overlook," Zehren said.

Steve Boomgarden, product advisor for The Hotsy Corp., Englewood, CO, echoed this viewpoint, and said routine and proper maintenance is important not only for cleaning equipment, but for any piece of machinery in a shop. "Without proper maintenance, the chances of breakdown increase dramatically," Boomgarden advised rebuilders. "When certain types of cleaning equipment become inoperable due to the lack of, or poor, maintenance, it can be devastating to your shop's daily operation. In many cases, if your cleaning equipment is down, so is the rest of your rebuilding production."

Besides improving the life of equipment, Bill Wessel, president of Kansas Instruments, Council Grove, KS, said the more efficient the maintenance, the more efficient the machine will operate to save a shop money. "Costs are reduced directly by the machine cleaning faster when it is maintained correctly," Wessel said. "Costs are reduced indirectly by lower expended costs such as utility bills and replacement parts that will be needed if maintenance is not performed."

Boomgarden said nearly all cleaning equipment manufacturers will have a recommended maintenance schedule to follow. "A typical routine maintenance schedule for most cleaning equipment would include checking for cracked hoses, seized pumps due to a lack of oil, sooty coils, screen cleaning, nozzle changes, changing the oil and any filters, greasing requirements, etc.," Boomgarden said. "This depends on the equipment and the number of components it has."

Boomgarden said having a comprehensive maintenance checklist by the cleaning equipment is a good idea. "Regardless of who performs the maintenance, the checklist will ensure that all pertinent items are looked at and maintained," he said.

When dealing with manufacturer's maintenance requirements, there are some general, common-sense guidelines to consider which will save the shop unnecessary aggravations. First, keep each cleaning unit's instruction manual clean, orderly and near the piece of equipment it belongs with. Second, ask your employees to handle the manuals only with clean hands, and request they do not tear out any pages. Third, make a photocopy of the manual and keep it in a secured place in case the original does get misplaced or destroyed. By taking good care of the manual, you can help ensure that it will be available for any employee who needs to refer to it for operation or for reordering parts.

The type of cleaning equipment will obviously dictate the costs associated with its maintenance. For instance, if you purchase a filtration mechanism, you will likely have to service filter membranes, replace filter bags/membranes/liners, and dispose of spent filters as a hazardous waste. This is also the case for chemical flocculating accessories for which you may have to purchase flocculating chemicals and filter liners, and dispose of the increased volume of sludge and filter liners as a hazardous waste.

One point to ponder before purchasing new cleaning equipment is to look into buying from a local distributor because the shortened distance may reduce shipping costs of parts and allow prompt service of equipment during any break-downs.

Ovens
When applicable, intake air filters should be checked which minimize intake dust which can cause finish flaws. Kansas Instrument's Wessel said ash should be removed weekly from the oven floor. "Also, the burners should be checked and blown off with clean, dry air monthly," he said. "Any dust collected inside the burner reduces its efficiency."

Aqueous units
Jet washers equipped with oil separation technologies may require about 20 minutes of daily maintenance at the end of the day while the machine cools. Those with filtration may require filter membranes be cleaned once a week, also about a 20-minute job. "Some filters never need replacing because they are made of a screen mesh," explained Hotsy's Boomgarden. "These filters need only be removed, washed off with a hose and replaced. However, other types of filters such as polyspun fiber or cloth fibers must be replaced."

Most machines, depending on the frequency of use, require periodic sludge removal and cleaning. This is typically undertaken between one and six times a year and can take up to two hours at each cleaning. Some companies are marketing sludge dryers or flocculating technologies. These processes may require even more service.

Spray nozzles on these units should be inspected regularly to avoid clogging. "Under normal conditions, spray nozzles will not get clogged," Hotsy's Boomgarden said. "However, occasionally a nozzle will clog due to either bad detergent that leaves deposits, or an accumulation of dirt and debris. To clean out the nozzle, simply remove it, tap it on a hard surface to remove the debris, wash it out and replace."

Boomgarden said most nozzles only need to be replaced when they wear out. Depending on how often the equipment is used, this can range anywhere from one to five years. "Nozzles are usually easy to find and most manufacturers use a standard 1/4ý or 1/8ý male-threaded nozzle," Boomgarden said, and offered the following recommendations to prevent clogged nozzles.

• Use only good detergent.
• Keep the equipment clean by removing sludge from the solution tank.
• Be sure the filter is clean or replaced on a regular basis.

Kansas Instruments' Wessel noted other causes for plugged nozzles that rebuilders need to be aware of. "Removing any stringy, non soluble substances such as silicone from the part before it is cleaned will keep nozzle plugging to a minimum," Wessel said. "Sediment build-up in the bottom of the machine causes most nozzle plugging, so tank maintenance is the key."

Goff's Zehren said his company's HydroPulse equipment, which uses a water wheel to centrifugally throw hot water in large droplets from large openings on the star-shaped wheel, was developed to eliminate the need for spray nozzles and their problems, yet still perform the same cleaning requirements. "By eliminating nozzles, we have eliminated the single most costly and timely wear item associated with pressure washing and cleaning equipment," Zehren said.

Shot blast equipment
According to Gus Enegren, president of Viking Corp., Wichita, KS, dust collection is an often overlooked and important area of shot blast maintenance. "Most users tend to focus on wear items, such as "how worn are my blades' or "is my material handling system worn out,'" Enegren said. "Too often they couldn't care less about the cleanliness of the dust collector filter media or the shot work mix. But those two issues, probably more than anything else, will determine the success of a blast cleaning operation."

Blast machine manufacturers said their maintenance checklists have dust collector condition as a "check daily" procedure. "The shot blast equipment could not operate without a dust collector removing the airborne dust and assisting the lip separator to remove heavy particulate from the abrasive mix (shot)," Goff's Zehren said, adding dust collectors for the most part are self-maintaining. "They do however require a timely and consistent removal of the waste dust. If waste dust is not removed on a timely basis, it can overfill and be re-entrapped onto cartridges or the filter," Zehren said.

And speaking of filters, Zehren said replacement of these items in a shot blast machine is determined by the work being performed and the load of dirt. "Under consistent and proper operating conditions, filters normally last one to three years," he said. "If, however, a bag or cartridge is damaged, torn or broken, then that filter needs immediate replacement."

Because of the nature of their operation, non-moving parts on shot blasters are subject to wear by the shot media itself. The wheels, impellers, paddles, baskets and baffle plates, as well as the doors and walls of the centrifugal airless cabinets, are all exposed to the abrasives. Frequent visual inspection and maintenance is imperative for this equipment. "The impeller blades, protective deflectors, housing and all inside parts should be checked for wear weekly," Kansas Instruments' Wessel advised.

Moving parts
All moving parts require some form of regular maintenance. Boomgarden said the frequency and degree of maintenance will vary depending on use, location and whether or not the moving part is exposed to a wet environment. "Naturally, moving parts, such as chains or gears which are constantly being exposed to water will require more maintenance because the lubricants get washed away," he said. "Here again, the manufacturer will suggest a proper maintenance schedule for most moving parts."

And don't forget to inspect pumps on the equipment. Today, most pumps are an impeller type pump," Boomgarden said. "These require very little maintenance other than greasing bearings once a month."

Belts and hoses
Goff's Zehren said checking inexpensive parts regularly will save a shop from unnecessary costs from wasted solution and the time needed to clean up spills. "Hoses should be checked daily for cracks," he said. "If a hose is in anyway damaged or shows signs of wear, it should be replaced."

Boomgarden said belts need to be replaced when they become stretched too far to be adjusted properly, break or suffer from severe cracking/chipping due to excessive age and or wear.

Adding accessories
Accessories for various cleaning equipment may also help reduce maintenance costs. Betty Rickards, marketing coordinator for Empire Abrasive Equipment Co., Langhorne, PA, said continuous dust collectors, which optimize cleaning production by purging dust from filtration surfaces while operating air-blast equipment, is a very popular accessory. Rickards said the continuous duty dust collectors, which are designed primarily for use with manual blast cabinets, are equipped with cartridge filters to maximize "up-time" and to simplify maintenance. "The normal cleaning of the filters during operation is via pneumatic reverse pulse jet cleaning," Rickards explained. "It only takes between a few seconds to several minutes to clean the filters, depending on how dirty they are."

Rickards said replacement of the filters depends on the type and duration of air blasting which is being performed in the shop. "It can be months or even years before you have to replace the cartridge filters," Rickards.

According to Rickards, these dust collectors capture 99.999% of particles one-half micron or larger. And besides keeping the cleaning equipment functioning efficiently, such filtering units have other benefits to a shop. "Because of their high efficiency, these filters permit recirculation of the air to the work environment, thereby reducing HVAC costs," Rickards said.

For aqueous equipment, Zehren said oil skimmers and sludge conveyers are extremely beneficial when applicable. "By removing oil and grease from the cleaning solution/water, the machine is more effective and offers better quality results," said Zehren. "Parts clean in less time and the machine requires less daily maintenance by removing this automatically from the solution."

Other issues to consider
To prevent damaging cleaning equipment, Delores Shaver, industrial sales manager for Ecolink, Stone Mountain, GA, a manufacturer of environmentally preferred solvents used in jet washers, said shop employees should be up to date on what cleaning solutions can be used in their particular washer. "Some solutions are not recommended for certain cleaning equipment," Shaver said. "Some solutions will deteriorate the equipment's hoses or seals." Many cleaning equipment manufacturers recommend solutions and chemicals used in their equipment contain rust inhibitors to protect the integrity of the steel cabinets.

And regular maintenance also keeps the cleaning equipment under a manufacturer's warranty. "Almost every manufacturer that I'm aware of will void the warranty if certain items are not maintained properly," The Hotsy Corp's Boomgarden said. "Just like with any automobile, if the oil and filter changes are not conducted on a prescribed schedule, the manufacturer will typically state that the warranty is null and void for service resulting from the lack of regular maintenance."

Goff's Zehren agreed, and said most rebuilding shops are aware of the warranty issues associated with not properly replacing wear parts to equipment. "It is the exception that shops allow this to happen, but it can and does in our industry," Zehren said.

The U.S. EPA Office of Research and Development, Washington, DC, offers a number of additional maintenance practices shops can perform to keep equipment in good working order.

• Rack systems should be maintained in good condition, free from cracks, rust, and corrosion which can flake off and contaminate the bath. Metal tanks should be properly coated with protective finishes both inside and out.
• The float valve that supplies make-up water to tanks of heated cleaning solutions should be maintained regularly. While maintaining an adequate level is necessary, it is also important that the valve does not leak and result in dilution of the cleaner. In addition to maintenance, routine analytical checks of solution strength are a good way to detect slow leaks. Decreases in solution strength during a time when the tank has not been used are a sure indication of a leaking valve (provided that the tank is not leaking).
• Screen solids before they reach the waste sump on aqueous equipment . The majority of the heavy metal residue, oil and grease removed from hot tank operations occurs after the actual hot use. The heavier concentrations of solid residues are found in the waste sump. The standard practice currently is to use a high velocity spray wand to dislodge these solids into the sump. Proper capture and disposal of these wastes is necessary. This can be done by use of a solids collection tray with overflow to the sump or periodic cleanout of the sump by a waste hauler for disposal at a Class I landfill.

By being aware of these requirements and following through with a regular service and inspection policy, rebuilders can increase the production of their work, reduce costs and at the same time extend the life of their cleaning equipment.