Driflex is an in-plant system designed to remove all free, emulsified, and dissolved water from oil in batches of any size.
Since 1852, Smith & Wesson® has been associated with high-performance and high-precision firearms for official (safety, security, protection) and recreational user. To maintain efficient production speeds and keep up with customer demand, Smith & Wesson’s manufacturing processes use approximately 30,000 gallons/year of machine lube oil. Of that total, 19,800 gallons are recycled annually. Processing and recycling this oil had become a significant problem, involving excessive costs and inconvenience of third-party oil treatment processes.
Oil processing and recycling is important in various manufacturing processes, including primary metal production, metal casting, mining and power generation. The machines using these lubricant and hydraulic oils require clean, dry oil for dependable operation. However, as it is used oil becomes contaminated with process particulate and moisture — causing gradual damage to machinery, and potentially leading to machine failure. Processing contaminated oil so that it can be reused is common, because it saves considerable costs over oil replacement.
When the contaminated lube oil began to interfere it machining operations, Smith & Wesson contracted a service to filter, clean, and dry the oil to remove all unnecessary moisture and contaminants. This oil processing and recycling program required Smith & Wesson to accumulate and store 1,500 gallons of used oil over a two-month period.
Next, the manufacturer enlisted the help of a mobile processor to treat oil, at a cost of $4,375 every month. The total cost of this program was $52,500 annually — a lower price per gallon than oil replacement would run, averaging $6 to $8 per gallon for mineral oil and up to $60 per gallon for synthetic oils. However, the still-significant expenses and inconvenience of using a contract service provider led Smith & Wesson to pursue a new oil conditioning solution.
A new filtration solution
MSC Filtration Technologies — a Pentair Industrial distributor — introduced Smith & Wesson to the Driflex™ oil conditioninging system, which launched a fast-tracked project with Henkel Chemical Management to evaluate the system.
|Smith & Wesson’s unfiltered machine oil contained a high percentage of fine metal casting and grinding dust, so a duplex, prefiltration cartridge was installed to treat the oil before it entered the Driflex system, and effectively remove moisture during the conditioning process. |
Driflex is designed to remove all free, emulsified, and dissolved water from oil in batches of any size. Initially, the system appealed to Smith & Wesson because of its convenience: it would allow the company to process oil in its own plant, on its own schedule, and in virtually any volume they wanted. In addition, keeping the oil processing in-house would eliminate the costs of clean-up services associated with off-site processors or third-party truck-mounted vacuum dehydrator systems. Not only did clean-up services cost tens of thousands of dollars annually, but they also presented the risk that the oil would be permanently damaged and lost during the cleaning process. Along with eliminating this risk and additional cost, it was apparent that Driflex system would improve overall oil quality.
Driflex oil conditioning couples Pentair’s patented UltiDri® membrane technology with high-efficiency filtration to remove known, harmful contaminants from vital lubrication and hydraulic fluids cost effectively. The system operates by flowing contaminated oil through a particulate filtration stage, followed by a membrane filtration and an air-drying process. The result is that both particulate and moisture are removed from the oil, and the oil is restored to optimal condition for reuse.
Smith & Wesson processes lube oil in 250 to 300 gallon totes, replacing two to three totes (or 500-900 gallons of oil) per week. To service the oil, the company selected a 4 gpm Driflex Model #DF-04L4CS400 to meet their volume and processing time requirements. A Driflex system of this size is capable of processing the company’s typical weekly volume of oil within a few days, with no external schedules to accommodate or third-party expenses.
Solving process challenges
Despite the comprehensive capabilities and advantages that Driflex offered, a few challenges remained. Unfiltered oil quality varies depending upon how many times it has been recycled in the past, as well as how much particulate and moisture it has accumulated over its service life. Smith & Wesson’s unfiltered oil presented a significant challenge, as it contained a fairly heavy load of fine metal casting and grinding dust: 350 mg/L, with particles ranging in size from 2 to 10 μm. This contamination prevented the Driflex system from achieving optimal oil conditioning. To handle this heightened contamination, a duplex, prefiltration housing unit — Pentair Industrial Model #H8836, containing 5 μm Triflex™ Mega Cartridges — was installed to treat the oil before it entered the Driflex system. This cartridge prefiltration system successfully removed the fine particulate before oil conditioning took place, allowing the Driflex unit to effectively remove moisture during the conditioning process.
Another difficulty arose when a process accident during the test period introduced a high volume of water to the unfiltered oil. After this incident, the oil’s moisture content registered at 2 percent — 20 times higher than normal. Despite these unusual conditions, the Driflex oil conditioninging system still delivered optimal results, though it took several additional days to process the oil. Through continued recirculation, the oil was processed until the desired level of dryness was achieved — without interruption to Smith & Wesson’s operation or the quality of the machine oil.
Overall cost savings
By employing the Driflex oil conditioninging system in their operations, Smith & Wesson has significantly reduced its oil processing and recycling costs. Having purchased the Driflex system, it achieved a return on its investment in only two months. And, the savings continue, as the system’s annual operating cost is $4,500 — compared to the $52,500 Smith & Wesson spent annually to accomplish the same task through an outside contractor.
An additional benefit of using the Driflex system is Smith & Wesson’s ability to recycle smaller batches of oil, which would have not been feasible to process though the prior solution. Often, small batches were discarded as the low volume prohibited them from being stored; it was cost-prohibitive to try to accumulate enough oil from these batches to make outside processing feasible. Now, Smith & Wesson can process and reuse oil in batches of all sizes, with no valuable resources going to waste, the value of which is still to be realized.
Acknowledgments: Pentair acknowledge Smith & Wesson as well as Henkel Chemical Management for their willingness to share specific operational and cost details.