BLOG ARTICLE
Why More Heat Treaters Are Moving from Wet to Dry Vacuum Pumps
NORTH AMERICA | 4 April 2025 | 5 min
If you’re in the heat treatment world, odds are you or someone you know has relied on the STOKES 212-412J Microvacs for your vacuum furnace applications. These oil-sealed rotary piston pumps have been dependable workhorses for decades. They’re easy to maintain, tough as nails, and reliable. We respect that—because we built them that way. So, when we say it might be time to consider switching to the new STOKES 212-412DRY Dry Screw Vacuum Pump, it’s not because the Microvac is lacking. It’s because vacuum technology continues to evolve and moved forward—and the benefits of going dry are becoming hard to ignore.
We get it—change can be uncomfortable, especially when what you’ve got is already working. But here’s the thing: in heat treatment, product quality is everything. Whether you're treating aerospace turbine components or automotive parts, a stable vacuum environment directly impacts the end result. With the 212-412DRY, we’re delivering just that—improved stability, better process control, and zero risk of backstreaming oil contaminating your product or damaging your furnace. That’s peace of mind, baked right into your process.
Let’s break down the benefits of both pump styles—because both have their place, and we want you to feel confident whichever direction you choose:
STOKES 212-412J Microvac (Oil-Sealed Rotary Piston Pump):
- Proven reliability and simplicity
- Easy to service with readily available parts
- Mechanically straightforward (single shaft design)
- Performs well under stable oil conditions
- Long-standing industry reputation
STOKES 212-412DRY Dry Screw Pump:
- Stable vacuum performance across a wide range of conditions
- Zero risk of oil contamination or back diffusion
- Enhanced monitoring capabilities (temperature, pressure, pre-failure alerts)
- Reduced maintenance costs and downtime
- Clean, quiet, and environmentally friendly
- Boosts overall product quality and consistency
Furthermore, when talking about the benefits of the new STOKES dry screw vacuum pump series, it’s not just talk—it’s backed by real-world results. Bob M. at Paulo’s Cleveland Division had this to say:
Transitioning to Stokes Dry pumps has significantly improved our process efficiency, reduced maintenance expenses, and created a quieter, more comfortable work environment for our Team. After evaluating numerous pumps, the Stokes Dry series consistently outperformed the rest, delivering reliable, hassle-free performance.
One of the key pain points with oil-sealed pumps is that over time, oil degrades—and so does vacuum quality. That inconsistency means more risk for your batches, more maintenance headaches, and more money spent on oil and disposal. The 212-412DRY eliminates those worries. No oil, no contamination, no degradation. Just a clean, reliable vacuum that keeps your parts in spec and your team focused on production, not pump upkeep.
Of course, dry pumps require a bit more care in installation and operation. They're not plug-and-play like their wet counterparts. But here’s the upside: that attention pays off. You get a more efficient process, fewer scrap parts, and tighter control over every heat treatment cycle. With built-in monitoring capabilities—like discharge temperature and pressure sensors—you can spot issues early, adjust conditions in real-time, and keep your furnace running at its best.
The STOKES Microvac has been a cornerstone of the industry for good reason, but if your goal is to push for better part quality, reduce waste, and modernize your process… the 212-412DRY is the logical next step. Same STOKES toughness, evolved for today’s demands. Let’s talk about how we can help you make the switch—confidently, comfortably, and at your pace.
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