Maintaining your wheel blast machine is crucial. Shot leakage can be annoying, but it does not greatly affect the machine’s blasting ability. However, shot buildup on the floor poses a slip and fall hazard. Abrasive material escaping at high speeds raises eye protection concerns. These issues directly relate to overall shop cleanliness and safety objectives.
A) Vestibule seals are normally of a flexible urethane, Lexan or rubber and wear or break over time. Order these replacements in advance for shutdown opportunities. Cabinet seals are designed to be changed out regularly and do not require great skill.
B) Shaft seals are robust and effective, but over time can loosen up allowing a trickle of shot that adds up over time. These shaft seals should be replaced when the shaft or bearings are replaced. Accumulating shot can destroy a bearing as well as being a safety concern.
Monorail slot seals are often overlooked because they leak from the top of the unit. This makes them hard to see during ground-level inspections. Regular visual inspection is needed. If left untended, shot will exit at velocity and make it to the floor eventually. These seals are often made of rubber and/or brush, as well as internal shielding made of manganese or cast materials. It is wise to have these materials on hand as well for maintenance at shutdown times.
Maintaining Your Wheel Blast Machine – Blast cabinet fitted with manganese plate.
Maintaining your blast wheel is the most common service task for all wheel blast machines. While blast wheels are bolt-on components, neglecting cabinet maintenance can affect the machine’s structure, safety, and overall performance. Regular visual checks are essential, typically every 100 to 300 hours, depending on operating conditions.
Blast cabinets are usually lined with replaceable cast plates, manganese, or AR plates. Viking blast cabinets do not have welded liners; all liners are replaceable. These cabinets are designed for longer intervals between inspections and maintenance. However, they are often overlooked due to personnel changes or maintenance shortages.
Neglecting blast cabinets and vestibules can cause structural damage. This damage may take longer to repair than it would to replace an internal liner. Small issues can escalate quickly. Temporary covers and makeshift patches should only be short-term solutions until proper liner replacements or repairs are completed. Ignoring these problems can jeopardize a significant investment in production capability.
Viking has a dedicated team of service personnel and service trucks ready to assist with these maintenance issues. We encourage you to consult Viking for repair advice or field service to maintain your wheel blast machine effectively.
Due to the maintenance-friendly design of the Viking blast wheel, it is not the top choice. However, it is the most maintenance-intensive part of all blast units. Maintaining your wheel blast machine and targeting the shot blast flow are crucial for blasting efficiency. After a Viking service technician performs a detailed visual inspection, they will identify maintenance and service issues. The blast wheels will be given the highest priority during this process.
A service technician will check the abrasive load on the wheels and visually inspect all components. This inspection occurs during the consultation about the cleaning results. VMAX blast control cages typically last for two blade changeouts. However, we often recommend changing them together to improve targeting efficiency. Viking engineers have determined the wheel and control cage positions using 3-D modeling.
As the control cage opening wears, it broadens the pattern. This change takes some abrasive out of the target zone, reducing efficiency and causing unnecessary wear on the cabinet. Depending on wear, the impeller is often replaced when the wheel is taken apart. The blast wheel liners, which some manufacturers may not include, are quite durable. A visual inspection during each blade change is sufficient. These liners can last for up to three blade changes, though this may vary.
Viking will always maintain a sufficient supply of blast wheel consumables. It is advisable to completely replace the wheel wear parts in your maintenance department. This includes the blades, impeller, control cage, and a set of three-wheel liners
Viking offers a dust collector with most of its units. Our service technicians can adjust the airflow and perform maintenance effectively. Viking dust collectors are designed to achieve 6 to 20 air changes in the cabinet each minute. This rate depends on the application and the correct duct speed. Negative pressure should be visible in the seals and air-wash separation system. Most collectors use magnahelic or photohelic gauges. These instruments measure the differential pressure between the clean and dirty air chambers in the dust collector. This pressure differential is the primary indicator of filter condition.
Filter cartridges typically have an operating life of 0-5 inches on the mag/photohelic gauge. It is important to keep spare filters in stock. This practice helps minimize downtime and avoids the need for emergency expedited freight. Dirty cartridges block airflow, which is crucial for several functions. It helps remove dust from the cabinet, cleans the abrasive in the airwash, and reduces velocity in the ducting.
Reduced duct velocity can create serious safety risks. Dust may build up in the ductwork before scheduled cleanings. Duct cleaning should occur as needed, but a thorough inspection is essential at least every six months. Clean the ducts if necessary. Be aware of your unique conditions that may require duct cleaning. Viking service technicians are not trained for this task. Therefore, it is crucial to hire a local contractor to inspect and clean the ducts of accumulated dust. Additionally, develop your own in-house capability for regular inspections. Ensure your company understands all NFPA safety requirements related to dust in your specific application. This knowledge will aid in making informed decisions about potential dust hazards and disposal methods. If you lack a dust hazard analysis, consult your local fire suppression service. They can assist with fire suppression, explosion protection, and mitigation. Always use a qualified installer and inspector for all fire suppression, explosion protection, and other safety needs.
Maintaining the air-wash system of your wheel blast machine is crucial. It ensures a steady flow of abrasive material into the storage hopper. This system also creates airflow that removes fines and dust from the abrasive. There is no advantage in using dust or abrasives that are too small to provide significant kinetic energy. Moreover, dust and sand can harm wheel wear parts more than clean abrasives. Therefore, it is vital to keep the air wash and airflow well-tuned. Your Viking technician can make these adjustments with basic hand tools. Depending on your needs, performing a sieve analysis may be beneficial. This analysis should be done on the abrasive returns in the storage hopper. While visual inspection of the abrasive is informative, actual data analysis can lead to improvements.
This one is not as difficult as some new wheel blast machine consumers may suppose. While important, it is relatively easy and inexpensive to change media if staying with the same base metal. This recommendation only addresses metallic abrasives. We recommend using the smallest carbon steel shot that provides the profile, and SSPC finish required in most cases. Carbon steel shot is the most cost effective if the application allows it. Smaller shot breaks down slower and causes less wear on the blaster. There are 11 basic shot sizes, and 10 basic grit sizes all with approximately the same cost per pound. In selecting abrasive, we prefer work from smaller media to larger in the media sizing process. Viking can recommend the right media selection and sizing. They also conduct in-house testing to confirm the necessary abrasive requirements. For more information about carbon steel shot or grit, cut wire, stainless steel or zinc abrasives consult a Viking service tech.
