weldless vs welded; 1/2" vs 3/8"

i searched and couldn't find anything specific pointing towards one or the other as a sure thing.

a few questions:
1. i get that a welded coupling on a keggle would be more stable and less prone to infection (but if its being boiled in wort anyway, the weldless won't infect the wort either), but for the cost of having it welded, isn't it cheaper and easier to buy a weldless kit? I've heard prices ranging from $40-$65 just to tig the coupler in, compared to $36 for something like this http://www.northernbrewer.com/brewing/s-s-kettle-valve-kit.html
what are the advantages/disadvantages of each?

2. if most of our hoses, racking canes, CFCs, etc are 3/8" ID (max), why do we put 1/2" couplings on our equipment? Even if the 1/2" coupling has a 3/8" ID (which it might, or close to it), whatever is used to connect the hose to the coupling, valve, etc, is going to have to be smaller in diameter and therefore restrict the flow to that volume, so why not 3/8" couplings and valves?

3. (edit) why is SS so prevalent? if our wort touches copper at any point, wouldnt it be less expensive to just use bronze instead? are there high-ranked sanitary issues that make SS better?

thanks in advance for furthering my knowledge base.

Everything on my rig is 1/2". Valves, QDs, hoses, HERMS coil/chiller....
I dont know that 3/8" is that common? 1/2" ID is great, epsecially when dealing with pumps and flow rates.

Good questions. Here's my take on them:

1. + Welded fittings are forever (or very nearly so)
+ Welded fittings make for a cleaner install. Can be welded flush on the inside which is nice.
- More costly unless you know a welder who might do the job as a favor or you do the welding yourself (if you have the skills and equipment; that's a big if)

2. First off, it's important to understand the plumbing terminology regarding tubing, pipe and the associated fitting. Tubing (soft copper, vinyl and PVC tubing) is specified by outside diameter (OD) while rigid pipe is specified by inside diameter (ID). There is a huge difference. The 3/8" hose (flexible tubing) is actually 3/8" OD and it's ID is substantially smaller at about 1/4". A 1/2" pipe coupling accepts pipe which has a 1/2" ID. The OD for that pipe is about 7/8" or so. Again, it's a huge difference, especially if you compare the cross sectional area. It's much more of a difference than you would expect. You are correct about the barbed adapter, quick disconnects etc that are often attached to these fittings. Many times these will be restriction points. IMO, bigger is better for all tubing, pipe and fititngs, within reason, of course. When using a pump all of this becomes even more important. I started off using the common 3/8" vinyl tubing for nearly everything. Then I bought a pump and upgraded to 1/2" for all. That's when I realized the problem with the adapters causing too much restriction so I finally upgraded again to 5/8" ID hoses all around. Just loved buying everything three times! Pumping or draining anything through a 1/4" ID whatever is like breathing through a soda straw. It can be done, but I would not want to do that for long or under exertion. A pump demands larger diameter tubing and pipe for best performance. IMO, this is not something to skimp on.

Weldless fittings will work just fine. Blichmann's stuff uses them for everything. I personally prefer welded fittings, but either will do the job. Only you can weigh the costs vs. what you would ideally like to have. Sometimes we must compromise.

If you are using threaded fittings, I don't think weldless vs welded is much of a sanitary issue since the threads are a worse issue than weldless.

I agree that sanitation is much more of an issue on the cold side, but do be aware that you are most certainly not boiling anything outside of the kettle. Sanitation aside, I would hope you want to keep your hot side equipment clean. IMO, everything should be broken down and cleaned regularly. A weldless fitting is just something else that needs to be broke down.

Weldless fittings might leak, welded will not.

Stainless steal is inert, easy to clean, corrosion resistant, commonly available and can withstand essentially any food safe cleaning regimen. There aren't that many bronze fittings available. You can use the similar brass but it is a little more finicky and fragile with respect to cleaning.

i use a CFC built off the DIY on HBT with 3/8" copper tube (essentially 1/4" ID), so is it worth having bigger tubes if i'm going to use that? i assume not.

also, i just purchased 3/8" tubing, QDs, etc and a pump (wish i had asked about this last monday). how long is acceptable, without killing my marchpump, before i upgrade then to 5/8" ID, if you found that to be such a big difference? is the strain that bad for the pump? and what would you use to cool your wort? a larger CFC? plate chiller?

You could put the CFC on the outflow of the pump instead of the inflow, that adds no strain to the pump.


Also, intuitively I would have to think that the smaller ID copper tubing would provide better heat transfer than larger in your CFC.

The restriction issue is cumulative. IOW, it's not just the narrowest restriction that's critical, but the sum of the frictional resistance of all the components in a run; ie the pipe and the fittings.

The suction side of the pump is the most critical to the pump performance. This is not to say that the pipe and fittings on the output side are not important, just less critical. You will want the CFC to be on the ouput side where you will be pushing wort through it instead of trying to suck it through. Yes, the 1/4" ID will be restrictive and slow the flow rate, but it will work. Your pump performance will still be better with larger hoses for the reason already mentioned. The resistance to flow is higher for smaller ID stuff and it adds up.

You won't kill your pump unless it gets to the point of cavitating which can cause damage if prolonged. You can prevent cavitation by using a valve on the output to control the flow rate. Cavitation will sound like gravel rattling inside the pump head, although air in the system can make a similar sound. Neither is desirable obviously.

I built hybrid CFC which uses 25 ft of 1/2" ID rigid copper pipe. I wanted a high flow rate for rapid whirlpool chilling and it does that very well. Chillers are a whole topic of their own and you can find a bunch of information right here on HBT with a little searching. There are commercially available CFC's which use large ID tubing and there are the hight efficiency plate chillers along with the tubing in a hose type such as you have. A lot of guys use exactly what you have and they pump through it without problems. It won't be the fastest, but that may or may not be a concern for you. Some don't force chill at all and AFAIK, they make perfectly good beer.

I'm pretty sure that most of the guys use 1/2" ID tubing for pretty much everything, so don't run out and buy 5/8" tubing just because that's what I'm using. I have some unusual personal preferences which may or may not be the same as yours. Only you can figure out what fits your system and style.

If you look around, you will notice that you will almost never see two identical DIY home brew systems or even methods for that matter. Sometimes the differences are minor and sometimes major, but differences there will be in systems and styles and that's a good thing IMO.

weirdboy said:

You could put the CFC on the outflow of the pump instead of the inflow, that adds no strain to the pump.


Also, intuitively I would have to think that the smaller ID copper tubing would provide better heat transfer than larger in your CFC.

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Yes it will, but there will be a trade off with the rate of flow, so the overall time may be less. There are some other variables involved such as the flow rate of the cooling water, the temperature of the cooling water, the length of the tubing, the diameter of the outer hose, convoluted tubing or not, etc., etc. I don't really know what the optimum configuration would be for all of these factors and there will be the law of diminishing returns to confront. Large plate chillers probably approach the most efficient cooling method, but then they have their own unique set of problems with the potential to get plugged up and difficulty cleaning/sanitizing. I have yet to see a one size fits all ultimate chilling solution.

1)Flow will be constricted at a bottle neck. Regardless of the biggest ID, flow cannot overcome the smallest ID. If everything is matched(1/2"), then the only restrictions in flow will be bends in the tubing. By using the 3/8" CFC you can't expect flow greater than the 3/8" can deliver. Cheaper is determined over time. If you have to break it down and clean it everytime is it cheaper?
2) You will have to ask the engineers why they came up with so many different sizes. The most important thing is to match the ID regardless of the OD of different tubings, pipes and fittings. But by installing bigger than what is "speced" for the pump, the only loss is do to lift ability of the pump. Since lift is not a major concern in our operation, then it falls back to the smallest diameter in the system being the bottle neck, the pumps are rated at 1/2". I used a 3/8" CFC for many, many batches before I switched to a plate to improve flow while keeping flow for chilling.
No it's not hard on the pump, they are magnetically driven. The difference is how fast it can cool when using a plate or larger diameter CFC.
3)SS is the best. That is not saying it is the only. It just takes less care. Bronzes are known to carry lead, do you want to take a chance? Also SS last longer, is easier to maintain, inert, does not corrode easily, and is tougher. Copper has better heat transfer ability but due to longevity issues SS ussally wins. Its your choice and its personal, some people prefer copper, some prefer SS.

Cat, I type way to slow.

beerthirty said:

1)Flow will be constricted at a bottle neck. Regardless of the biggest ID, flow cannot overcome the smallest ID. If everything is matched(1/2"), then the only restrictions in flow will be bends in the tubing. By using the 3/8" CFC you can't expect flow greater than the 3/8" can deliver. Cheaper is determined over time. If you have to break it down and clean it everytime is it cheaper?
2) You will have to ask the engineers why they came up with so many different sizes. The most important thing is to match the ID regardless of the OD of different tubings, pipes and fittings. But by installing bigger than what is "speced" for the pump, the only loss is do to lift ability of the pump. Since lift is not a major concern in our operation, then it falls back to the smallest diameter in the system being the bottle neck

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I don't want to insult you or start a big argument, but most of the above isn't correct. Smaller diameter pipe, tubing and fittings will have more frictional resistance to flow than larger diameter equivalents and that's a fact.
IOW, a combination of large pipe and small fittings will perform better than a combination of small hose and small fittings. (assuming the large and small are the same diameters in each case ie, 3/8" vs 1/2"). Keeping the fittings the same size and only increasing the pipe diameter will reduce the frictional losses.

The standard engineering practice is to convert all frictional losses to dynamic head loss for design purposes, or what you are referring to as lift. "Lift" certainly is a major concern when it comes to moving fluids. It's all about lift or dynamic pressure head. I'm not an expert in hydrodynamics, so maybe one of our engineers who is can explain it in more detail, but I'm confident that I've got it basically right.

Catt22 said:

Yes it will, but there will be a trade off with the rate of flow, so the overall time may be less. There are some other variables involved such as the flow rate of the cooling water, the temperature of the cooling water, the length of the tubing, the diameter of the outer hose, convoluted tubing or not, etc., etc. I don't really know what the optimum configuration would be for all of these factors and there will be the law of diminishing returns to confront. Large plate chillers probably approach the most efficient cooling method, but then they have their own unique set of problems with the potential to get plugged up and difficulty cleaning/sanitizing. I have yet to see a one size fits all ultimate chilling solution.

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Well, I might do some research on the necessary equations, and set up an optimization problem that accounts for all the variables just to see what comes out. I suspect the result would be a pareto surface that is limited by the ratio of diameters of the inner and outer tubing and the difference between the flow rates.

nbspindel said:

2. if most of our hoses, racking canes, CFCs, etc are 3/8" ID (max), why do we put 1/2" couplings on our equipment? Even if the 1/2" coupling has a 3/8" ID (which it might, or close to it), whatever is used to connect the hose to the coupling, valve, etc, is going to have to be smaller in diameter and therefore restrict the flow to that volume, so why not 3/8" couplings and valves?

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Actually, if I were to do it again, I would go BIGGER... to 1 inch.

Yes, it is more expensive but it is much easier to clean. In addition, SOME elbows for 1/2" get really tight inside.

I use a mix of bronze, copper, and stainless steel on my AL and SS kettles.

I use a mix of bronze, copper, and stainless steel on my AL and SS kettles.

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So you're brewing with a big battery?