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With my old setup, I used a motorized water valve to fill my HLT, but now my new setup does not use an HLT, so I will be filling my Mash tun directly with hot water, and worried about lead leaching in because of the higher temperatures. The only 3/4 inch lead free brass valves I see are very expensive. There are stainless ones too, but isn't it not good (or a pain) to connect stainless to the copper pipes?
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Firstly, I must admit to not expecting lead leaching from brass to be a problem, bearing in mind that old breweries used loads of brass fittings (undoubtedly never completely lead free), and they never seemed to (nor still do where this kit has not been replaced by SS). However, I have worked in a few breweries with a mix of stainless steel and copper / brass / bronze. The biggest problem was (this was a few years ago) finding decent pipe stranglers who could fit stainless securely to copper, brass or bronze.
I believe the potential problem of lead extraction is worse in soft water areas, so for instance, as I understand it, domestic pipe work in lead in soft water areas of the UK was prone to dissolving slightly more rapidly than hard water areas. Presumably the same applies in other parts of the world.
Have you had some mineral analyses done on your current lead content which indicates this might be a problem?dick -
Dick is right in a sense, the lead will not be a "real" problem. Ironically "lead free" doesn't even mean lead free. It usually tells you somewhere in the fine print that the lead content is below 0.25%.
All brass is likely to contain some trace amounts of lead, but its really not much nowadays. They went down from like 8% to the 0.25% standard a few years back. The lead is alloyed for a couple reasons, but I suspect the majority nowdays is simply from previously alloyed brass mixing into the new castings. Lead tends to leech out early in use due to the surface area contact. I imagine, as Dick suggests, that the langelier saturation index has a good bit to do with it as well. Basically its a measure of corrosion vs mineral deposit. I'd imagine corrosion brings more lead into the water while scale would cover it up.
Connecting two dissimilar metals can cause galvanic corrosion, but this can be bypassed quite simply. Use a plastic washer, or a short piece of PEX, HDPE, etc to break any electrical charge between the two metals. Just like your home water heater.
As Dick also suggests, mating dissimilar metals can be difficult because the hardness of the metals is different. Stainless threads are notorious for leaking due to their hardness. The softer metals often give a little when tightening to mate better and seal on the 60* thread interfaces (NPT).
Buy once, cry once. Stainless.Comment
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This is the one I was thinking of getting, they make it in brass and stainless, and while reading the spec for the brass I see this: "WarningLead content ~ 3.05%. It cannot be applied to drinking water."
The stainless isnt that much more, but I do worry about the pain of connecting stainless to brass. I would love to get the brass one just for the ease of installation and I do live in Chicago so we have somewhat hard water (although we will be using sediment and charcoal filters, if that matters?) I just want to make sure I am not doing anything that is unsafe.
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Connecting the pipes is nothing to be worried about at all. Just get some good quality PTFE paste and goop both the male and female ends. Tighten snug, but don’t get carried away. Use a shorter piece of pipe nipple (sacrificial) if you are really worried about galvanic corrosion.
I have recently been replacing some brass adapters on glycol jackets because someone felt the need to over tighten them significantly on installation (fear of leaks). With the Coefficient of Expansion not really considered, thermal cycling has cracked several now, ironically causing leaks. Replacements focused on better sealing and have had no issues yet.Comment
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