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What is the importance of weld-free design?

Our competitors talk about the quality of their sanitary welds and the skill of their welders. But a sanitary weld is nothing more than a procedure done in an oxygen-free environment on both sides of the weld using an inert gas. These welds are usually done from the outside of the tank while the inside of the tank (which is the critical area) is not visible to the welder while welding. Others do weld from the inside, but the small, confined area makes this weld very difficult and requires "elaborate" procedures to produce a reasonable-quality weld. Because there is little oxygen in the area of the weld, burning and porosity are greatly reduced but not completely eliminated.

In the real world, there is no such thing as a microscopically flaw-free weld, to which any welding engineer can attest. Depending on the skill of the welder, and the day he or she is having, remaining flaws (quench cracks, porosity, and cold laps) will vary and are usually not visible to the naked eye. Many elaborate methods are used to reduce these flaws, but unless they are microscopically inspected and repaired, there is no way to determine if the flaws in the weld are small enough (0.5 micron or less) to not present a sanitation or corrosion problem.

Clearly, the best design is one that is not susceptible to human or process error and doesn't require elaborate welding procedures to reduce quality problems. Subsequently, that design will have little variation in quality. This was the driving force in the design of the Fermenator™, and Blichmann Engineering quality is very high, very repeatable, and absolutely free of any possible flaw. Our weld-free fittings are easy to install and thoroughly clean, which simply cannot be done with a welded fitting.

Why do commercial breweries use welded tanks and fittings? Due to the sheer size of commercial fermentors, they are made by welding rolled sheets of steel together. The welds are subsequently ground, polished, and then non-destructively tested for microscopic flaws. Because commercial breweries often utilize hot steam for sanitization, it is less of a problem even if a flaw is present.

Because homebrew-sized fermentors are too small inside to grind and polish from the inside, these flaws can't be removed or detected. Plus, improper grinding techniques can also cause micro-cracking. Steam-sanitizing is not a realistic option for homebrewers. Fortunately, homebrew tanks are small enough to be deep-drawn from a single sheet of stainless steel and formed without any welding whatsoever. So why take a flaw-free tank and add welds to it?

What happens in these flaws?

Obviously, they are a good place for bacteria to hide because liquids carrying sanitizer have a hard time penetrating these small flaws, due mostly to the water's surface tension. Because oxygen can't readily travel to these flaws, the protective CrO2 layer that stainless steel naturally forms in the presence of air (oxygen) can't form on the walls of the flaw. Eventually, these flaws will grow through rusting of the base metal (iron). In extreme cases, these flaws can propagate through the wall of the tank and leak.

Although weld-free fittings are more expensive than welded fittings, Blichmann Engineering advises it for peace of mind, clean bacteria-free beer, and a fermenter that will last a lifetime.

Compare interiors:Fermenator (Left) vs. competitor (Right)

High-quality fittings

All fittings used for the bottom dump and rotating racking arm are specially made, stainless-steel, high-quality industrial fittings, not makeshift hardware store parts and pipe fittings sandwiched between o-rings like most "weld-free kits" available at homebrew supply stores. Competitors' designs utilize compression fittings, which have inherent corrosion and bacteria problems. The ferrule on a compression fitting locks in place on the racking tube and, as above, prevents a flow of oxygen to the surfaces under the fitting, which allows pitting and corrosion to take place. Threaded fittings that can't be disassembled exhibit similar phenomenon. Others use short pipe nipples that can't be easily disassembled. The Fermenator, on the other hand, uses a flare fitting to eliminate this problem. All threaded fittings have hex flats for easy disassembly, and the o-ring design is identical to hydraulic systems capable of holding 4,000 PSI of pressure!. Again, it's more expensive than welding, but well worth the added cost.

Easiest fermentOr to clean

unlike welded fittings, ours can be removed for easy cleaning by sanitizer, boiling or autoclaving.

Because one side of the fitting on all competitive models is welded to the tank, it can't be removed, and flooding those surfaces (particularly threaded fittings) with sanitizer is difficult at best. That's why they recommend you Clean In Place (CIP) with expensive cleaners and time-consuming soaks. In less than a minute, you can remove the bottom dump and racking arm assemblies in your Fermenator and have them ready for a good cleaning. If you're obsessed with sanitation, you can completely disassemble them in a few minutes more. Even then, it's much faster than readying all the CIP circulation equipment and significantly more thorough. Rest assured that you've got every nook, every cranny, every time, in just a little time. You choose the cleaning method that's right for you!

Replaceable fittings

Our competitors' welded-in fittings can't be replaced if they get accidentally damaged or wear out. Cutting and re-welding are the only way to repair a damaged or worn fitting on their tanks.


Weld-free fittings let you orient the dump valve in any position you want, not where it happens to end up when tightening a welded fitting such as facing the rear of the refrigerator!

Guaranteed 100% Leak Free!!!

Our optimized design, identical to hydraulic systems under thousands of PSI, is also guaranteed to be 100% leak-free. Even the lid seal can be fully immersed under pressure!

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