I only went as far as considering using an industrial quality valve. Though that was going to come next if I hadn't found out that the stock ones are serviceable/rebuildable. I have a ton of non-cupped PTFE seals that are otherwise the right thickness and diameter. I got a bag of a hundred from AmazonUSA for under $10USD. I put some in one of my spare ball valves a couple of days ago to try when my flipped seals eventually leak again. From my perspective this issue is solved.

HOWEVER, I'm not in the least disinterested in the bling of an industrial quality valve... as long as they too are serviceable like the Breville valve. I'd hate to have to fork over the $$$ to buy a new one every time it's needed.

-Peter

Agree about tinkering. And how cool it would be to have an industrial ball.

I'm on a trip right now but I'll check the valve with the non -cupped seals when I get back.

-Peter

Brendan, you are pole vaulting your way up the ever prestigious, "BDB mad skillz" charts. Amazing efforts by you to learn and do. Very well done, mate. Please keep contributing.

-Peter

Sooo... There have been two approaches to servicing the steam ball valve, which we have found is re buildable instead of disposable.

When the steam wand drip eventually starts, it appears it's' due to the seals in the valve, getting "loose" and no longer pressing against the ball with enough force to hold back the steam.

There have been two approaches to fixing this that I have noticed. My way, and everyone else's way.

1) what everyone else has done has been to add some sort of shim underneath the steam side seal, so that when you screw the two halves back together, the steam side seal now presses tighter against the ball, and your drip goes away. Well done. I think what drives this approach is the desire to keep the conical side of the seal, against the ball. (Somebody correct me if this assumption is wrong).

2) what I have done differently is to take advantage of a unique characteristic of PTFE. This is the fact that it acts like a thick liquid and will flow without being heated, to make the shape of whatever it's pressed against. Thus from my perspective, there is no need or reason to keep the conical side against the ball. If you flip the it over and put the flat side against the ball, it will slowly flow and conform to the shape of the ball. Engineering geekery alert: you do not need a conforming surface to make the seal. The seal in a ball valve is made by a line of contact, not a surface of contact.

Here is a pic of what was a perfectly flat, non conical PTFE washer a couple of days ago, taken out of my bag of 100 PTFE washers I got off EbayZon for a few bucks. Now it's perfectly conical, and this is why I don't see flipping the seals as a hack. It's exactly how the system was designed unless somehow the engineers did not understand PTFE, and simply made a fortunate blunder (doubtful):


Both methods obviously work. So why do I think flipping the seals is better? Well, since leaks eventually develop when the seal becomes loose against the ball, by seal flipping, you don't have to tighten the two halves of the valve body all the way. Just tight enough to make the seal. Over time, (two years or so?) the seal will flow and become loose again, just like it did when new. Then you can tighten some more without having to disassemble and go another two years. So what's wrong with shimming? Well, if you keep adding shims, you are also adding extra volume of material to a limited space. If you don't manage it right, the PTFE will have to flow somewhere and it may go towards closing or distorting the shape of the hole. Now, the hole is MUCH bigger than it needs to be, so distorting it and shrinking it may be much adieu about nothing, and my argument may be more one of elegance than actual function.

So there. Two perspectives. Both work. When you get your steam leak as we all eventually do, you can fix it either way you choose.

-Peter

It's... possible of course. But we're only talking about an 8 psi increase, from 45'ish PSI to 53'ish absolute pressure. Of course that An 18% increase in absolute pressure so not quite trivial.

For the record, I still had my old -900 until summer 2018 and that only had the tiniest drip after six years. Probably first developed at three four, but it never got much worse. The-900 did not have selectable steam temperature. Now that I've had a -920 for the last year and a half, I haven't bothered to change it hotter. I don't drink many milk drinks and when I do they are tiny amounts of milk so the lower pressure gives me better control anyway.

So maybe my good steam valve durability has been due to running at lower pressure? :shrugs

-Peter