Breville Dual Boiler ball valve detail, pics - Page 8

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pcrussell50 (original poster)

#71: Post by pcrussell50 (original poster) »

Yes, Chris the Phobya is the one. When I doubt, one should stay in his comfort zone, but it is pretty clear that the Phobya is brass body, steel ball, brass stem, and bright white Teflon seal... Just like the Breville. Since the suspense is killing me, I think I might install it tomorrow to see how it goes, and just deal with the reverse logic. Then we'll know. We'll all know.

Other things...
1) My old leaky Breville valve that was kindly donated to me: If I can get the ~'|•√π÷׶∆ thing unscrewed, I can take it apart. From there, I might be able to tell if we can use the Breville stem on the Phobya, to at least go back to normal logic while using the Phobya.

2) I just ordered the stainless steel ball valve from Ali express, linked a couple of pages back. It gets rave reviews on quality for price. Looks like it might require some fitting.

3) If I can get that same @#$%&-+() old leaky valve unscrewed, I think I can measure up the diameter and thickness of the sealing rings, use a cheap Chinese eBay hole punch of the right diameter, and one of the right inner diameter, and put it all back together. The concept of cold flow was brought up a couple of posts ago, and Teflon is known to cold flow. This could actually play to our advantage. Tentatively, I have high hopes for this.

LMWDP #553


#72: Post by Windgoi »

I tried checking other 1/4 inch ball valves to see if I could use the seals before I used the spacer. The couple I tried were all different sizes.

No luck with Breville in the US. They force you to service.

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pcrussell50 (original poster)

#73: Post by pcrussell50 (original poster) »

Windgoi wrote:I tried checking other 1/4 inch ball valves to see if I could use the seals before I used the spacer. The couple I tried were all different sizes.
This is why I have higher hopes of cutting my own.

By the way, Breville uses the BSPP (British Parallel Pipe) thread format. I think it's the same pitch as NPT, but the cross section of each thread is a little different... IMS. So NPT and NPP might screw into BSPP, but the non matching thread cross sections might still leave a leak path.

It can't be stressed enough... Fantastic first post from you. It has kicked my butt into motivation to solve way or another, even though I have two brand new spares.

LMWDP #553


#74: Post by Windgoi »

All, Here is my latest thought on the ball valve seal on how we might make one.

If I/we can find a Teflon washer about the same size 10mm and the same thickness or slightly thicker (for wear adjustment). I could mount the Teflon washer in a fixture in my drill press and cut a cupped surface into the Teflon washer that matches the OD of the ball in the valve.

My thought on how to cut this is by using a mounted stone abrasive grinding stone. Like you use in a Dremel or Flex Shaft.

Example: ... ay&sr=8-46

1) Start with finding a fine grit ball ended grinder of the same size as the ball in the valve or larger.
2) If larger, I have shaped custom stones by spinning them on a high speed in the Flex Shaft with a harder stone. Measuring with calipers as you go.


pcrussell50 (original poster)

#75: Post by pcrussell50 (original poster) »

I took one of my perfectly good, brand new steam ball valves apart yesterday because I couldn't open my leaky old used one. There was a layer of thread locker on it so be VERY careful to push your 6mm hex wrench in deep enough that you don't strip out the hole. My recommendation based on the fact that my barely used, new one came apart easier than my old leaker, is to prophylactically remove and open your new one just to break the thread locker, then put it back together and keep using it until you need to seal the leak. The way it is installed, it is unlikely to rotate loose anyway.

I'm just about to drop an order on Amazon for some 10mm OD x 2mm thick x 5mm hole flat, PTFE washers. From China, so it will take a month to get here. These are the dimensions of the Breville washer, which I just measured up this morning. ... way&sr=8-5

They do not have the bevel to better fit the Breville ball. Two thoughts though: first, Rodger's Dremel ball. I like this a lot. Second, this is not brain surgery precision required here. And PTFE does cold flow. It might be possible to either not bevel it out at all, OR, scrape in a simple bevel with a pocket knife and that alone might be all that's required.

Finally, ancillary related... I have seen video on youtube of ball valve leakage around the actuator shaft. That is usually sealed by an o-ring. A proper ball valve rebuild should include a new o-ring with a dab of silicone grease, IMHO.

Overall, I am VERY hopeful about where this is going. Very much so.

LMWDP #553

User avatar

#76: Post by lancealot »

Thanks for putting your energy into this.


I have ordered a smattering of small ball valves to see if I can find matching seals. I see that you haven't had the best of luck with that, but I ordered my valves before you posted and they are not expensive. The crux of this in my estimation is going to be finding a valve seal with a seating surface that matches the size of the ball. As long as the thickness and diameter is larger than needed, those can be changed. I think that will be the same issue as you try to make a seal too - making sure the curvature of the seating surface matches the valve's ball. Good luck with this.

I am not going to get too far with this until I get a junk breville ball valve or I bite the bullet and buy a new breville spare. I simply do not want to go messing with the functioning one I have in my machine to solve this.


Last week I reported that I was able to tighten the sealing assembly inside my stock valve. So far, so good on this front. When I took the valve out of my machine and took the fittings off the ends, they were really loose. Perhaps this valve gets leaky due to wear or compression of the seals over time. Or perhaps due to the heating / cooling cycle and the vibration pump, the assembly that compresses the seals gets loose too.

Either way, maybe my fix of retighting will work or your fix or putting a shim in between the seals and the nut will work too. Who knows.

User avatar

#77: Post by lancealot »

Peter beat me to the post :D

I just looked up the pressure of 285f steam, it is 40 psi.

I seem to agree with your sentiment that cold flow might help us and precision might not be the most important thing for making this seal. Maybe in the future we will know better or maybe there is a steam seal engineer laughing at us but we WILL find out!

I agree that we will need to figure out how to replace the o ring(s) that seal the stem eventually.

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#78: Post by Windgoi »

When I worked on my valve. I looked at trying to replace the seals on the valve handle exit point on the stem. When I looked closely, It appears the stem is threaded in, then they cold formed a stop point on the outside. This notch prevents over rotating or backing the stem out. This would require removing the cold form edge of the case that creates the stop point to get to the seal.

pcrussell50 (original poster)

#79: Post by pcrussell50 (original poster) »

I recommend you try this:

My stock Breville ball valve shaft pushes down into the valve body and drops through , as long as you have the ball out of the way. Seems to be held up only by tension from the o-ring. In fact, I just had one out and put it back together with a dab of silicone lube.

I measured out the o-ring on the shaft and it appears to be a #8 or #9. They both have the same cross section/thickness. I'm going with #8. I'll order some up at the same time as my washer order.

LMWDP #553


#80: Post by bhennessy »

Here is a US supplier of 1000 psi stainless ball valves. Not sure of the handle orientation as it can't be seen. ... i-wog.html
1/4" Stainless Steel (316) Mini Ball Valve - Female by Female NPT is 42mm

Same on Amazon ... B006VE3C4A
Cheaper on Walmart ... /873372894