What's the advantage of welded ports?
This is a question we get often from customers looking to upgrade. The main types of connections are 'welded' and 'weld-less'. Weld-less connections utilize a hole in the vessel and that you would stick the valve, thermometer, etc through. A nut and o-ring is then used to make a seal. The main disadvantages with weld-less are they aren't as strong, sanitary and they WILL leak at some point. O-rings wear out. If you happen to have one wear out during a brew day, well, you know how that ends....
The other option is welded. Welded fittings are objectively better (thus the reason they cost more). They are stronger, more sanitary and will never fail. However not all welded fittings are the same. A popular term when talking about welded fittings is 'sanitary welded' or 'back purged'. When stainless steel is melted during welding it can't come in contact with oxygen otherwise it'll 'sugar' and produce a nasty compromised weld area. That is why inert argon gas is used during welding to shield the weld puddle from oxygen. However a properly done weld will actually penetrate through the metal to the backside ensuring a fully adhered joint. That means the backside weld needs to be shielded with argon gas as well. This is where the term 'sanitary welded' or 'back purged' weld comes from.
We weld all our tanks according to AWS standard D18.2 which ensures the weld was done properly and will not have issues down the road. This is quite different from tanks welded overseas where the back purging is not done and instead the 'sugaring' and nasty backside weld is ground down. To the naked eye this will look smooth (most of the time) however the material has been compromised and will form pits, cracks, rust, etc overtime. That's why you'll be able to see a weld bead on the inside of our fittings. We don't grind these down because we don't have to; we weld our tanks correctly and we're proud of that beautiful looking sanitary weld. There's a reason why we have an entire team of welders and fabricators at our Milwaukee facility; to ensure we produce the best looking and performing welds on the market!