Post by: Gattopardo on 10 November, 2018, 08:04:41 pm
(https://www.bialetti.com/images/BrikkaIllustr.jpg)
The worry for me is that the brikka has a weighed adaptor on top of the made coffee spout, to make a sort of crema on the coffee.
(https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRSM1ISomLK8qc1ijjmzA6psz62o7CEkWT-Y-rAWQzT7YBtaEHM)
(https://i.stack.imgur.com/5c8LP.jpg) So would that mean extra attention?
Post by: ElyDave on 10 November, 2018, 08:18:43 pm
Give it a very good scrub internally and externally, both halves of the pot.
Post by: Kim on 10 November, 2018, 09:32:46 pm
Post by: Gattopardo on 10 November, 2018, 09:40:46 pm
Do not EVER block off a safety valve, under ANY circumstances.
Give it a very good scrub internally and externally, both halves of the pot.
The problem is the valve, the rubber seal has gone.
(http://nebula.wsimg.com/450bce6cec8e5083a2acd0807bb21dde?AccessKeyId=E4EA2AD44B45A3FD785B&disposition=0&alloworigin=1)
Seeing as I don't tamp the coffee, and the coffee is not a fine ground it should not be a problem.
Post by: ElyDave on 10 November, 2018, 09:45:29 pm
Safety consultant, chemical engineer here, and Kim. Just NO.
If you know the seal has gone, replace the seal. Anything else is just fucking stupid.
Post by: Brucey on 10 November, 2018, 10:32:15 pm
Do not EVER block off a safety valve, under ANY circumstances.
Give it a very good scrub internally and externally, both halves of the pot.
The problem is the valve, the rubber seal has gone.
(http://nebula.wsimg.com/450bce6cec8e5083a2acd0807bb21dde?AccessKeyId=E4EA2AD44B45A3FD785B&disposition=0&alloworigin=1)
I suspect that it ought to be possible to fit a new seal by pulling it out/poking it in through the hole on the pressure side of the valve, once the valve is pulled open. Before you do that, do make sure that it isn't just a rogue coffee ground jammed in the seal, making it leak.
FWIW the Brikka is a bit more like a steam bomb than the other Bialetti models, because it has a weighted pressure valve (a bit like a pressure cooker I think). Running it without a functional safety valve would be completely mental. With any such machine there is a chance that coffee will jam the holes inside and cause an excess pressure inside.
You ought to be able to test the safety valve without any risk by (say) using a bicycle pump (with a gauge) on it.
cheers
Post by: Ben T on 10 November, 2018, 10:33:57 pm
Do not EVER block off a safety valve, under ANY circumstances.
Give it a very good scrub internally and externally, both halves of the pot.
+1
And turn the heat down you nutter!
Mine spews steam out the valve if I have the hob on 9 for the entire extraction, but not if I have it on 5.
If I want it quick I bring it to the boil on 9, but turn it down to 5 once it starts to produce.
My understanding of physics is that expanding steam could easily beat welded steel joints in a battle of strength. The whole thing could blow apart and send fragments everywhere. Don't think about blocking the valve, get a new one if it's not working.
Edit: mine has got a safety valve on the SIDE of the water chamber. Are we talking here about one that has got the safety valve in the top, ie where the coffee comes out?
Post by: FifeingEejit on 10 November, 2018, 10:46:13 pm
Quite. Steam explosions can ruin your day faster than you can say "BLEVE".
A hiking club mate once in his professional capacity attended the scene of a pressure cooker explosion...
https://www.bbc.co.uk/news/uk-scotland-tayside-central-29125339
His description of the scene is considerably more graphic than any of the press reports were which generally limited themselves to "lost part of a leg" presumably so that their readers could finish their breakfasts without ejecting them.
Post by: aidan.f on 14 November, 2018, 04:53:12 am
Quote
Designed to enhance your coffee drinking experience, the Brikka is equipped with a special patented valve that regulates just the right amount of pressure, producing the perfect froth every time..https://www.bialetti.com/coffee/stovetop/brikka/spare-parts-c-1_7_24_34.html (https://www.bialetti.com/coffee/stovetop/brikka/spare-parts-c-1_7_24_34.html)
So as ∆ upthread ∆ Service it, then use less heat!
I have always used boiling water in this type of coffee maker to speed the process. I also think a kettle uses less energy for the initial water heating.
Post by: Diver300 on 14 November, 2018, 11:24:40 am
Fitting the wrong 2nd stage, or blocking the connection to the 2nd stage has several time resulted in the next-weakest item failing. Someone who did that told me that the remaining hose burst, and the far end of the hose was found 50m away.
Taking the pressure relief off the aluminium superheated steam bomb is not a good idea, even temporarily.
Post by: rogerzilla on 24 November, 2018, 08:50:05 pm
Post by: Feanor on 24 November, 2018, 08:56:28 pm
It's much too compressible, and the stored energy is high.
Pressure tests are usually done with water or another fluid with low compressibility.
Much less stored energy.
So if it fails, it fails with a phut, not a bang.
Post by: T42 on 25 November, 2018, 05:17:54 pm
Post by: ElyDave on 25 November, 2018, 05:28:15 pm
Post by: yorkie on 25 November, 2018, 06:23:03 pm
Pressure tests are generally not conducted with any gas!
It's much too compressible, and the stored energy is high.
Pressure tests are usually done with water or another fluid with low compressibility.
Much less stored energy.
So if it fails, it fails with a phut, not a bang.
My father is the proud owner of a 1915 steamroller. Every spring he has his annual appointment with his boiler inspector. This starts with a visual inspection, using cameras and the mk1 eyeball, then progresses to a hydraulic test, where water is pumped into the boiler to a greater pressure than the normal maximum working pressure - usually about 20% over, I think. (I could be wrong with the 20%, it may be 25% or more!)
If there are no leaks with water, the inspector makes an appointment for another visit to test it under steam. They don't do that the same day, as it takes a while to get the water level back down to normal and to raise steam to working pressure - 125 p.s.i. in the case of the father's engine. Once the boiler passes the steam test, the inspector issues a certificate stating that the boiler is passed safe for 14 months.
Everybody who has a steam powered vehicle has to pass these tests, the insurance companies don't mess about when it comes to insuring something that can cause a *lot* of damage when it goes **phut** - it makes letting the magic smoke out look like a Sunday school picnic, if you'll pardon the mixed metaphor!
Post by: LittleWheelsandBig on 25 November, 2018, 06:30:15 pm
Post by: ElyDave on 25 November, 2018, 06:34:10 pm
In Germany, the whole concept of national quality and inspection systems developed from steam boilers and the deaths resulting from not consistently inspecting them. https://www.tuv-sud.com/about-tuev-sued/history/part-1-1866-1900
Pretty much the same in this country as well
Post by: Salvatore on 26 November, 2018, 12:16:02 pm
Post by: fimm on 26 November, 2018, 01:38:08 pm
Post by: ian on 26 November, 2018, 01:56:53 pm
(https://farm5.staticflickr.com/4017/4460206142_afeff35cd0_z.jpg?zz=1) (https://flic.kr/p/7N8HTU)Beaver Mills Boiler Explosion, Keene New Hampshire (https://flic.kr/p/7N8HTU) by Keene Public Library and the Historical Society of Cheshire County (https://www.flickr.com/photos/keenepubliclibrary/), on Flickr
Blimey, how much coffee were they making?
Post by: ElyDave on 26 November, 2018, 02:11:42 pm
(https://farm5.staticflickr.com/4017/4460206142_afeff35cd0_z.jpg?zz=1) (https://flic.kr/p/7N8HTU)Beaver Mills Boiler Explosion, Keene New Hampshire (https://flic.kr/p/7N8HTU) by Keene Public Library and the Historical Society of Cheshire County (https://www.flickr.com/photos/keenepubliclibrary/), on Flickr
Blimey, how much coffee were they making?
Only one cup, but they blocked the safety valve!
Post by: T42 on 26 November, 2018, 03:24:05 pm
https://books.google.fr/books?id=N-u0AwAAQBAJ&lpg=PP1&dq=dorothy%20hartley&pg=PT24#v=onepage&q=dorothy%20hartley&f=false
Post by: trekker12 on 27 November, 2018, 04:46:31 pm
Pressure tests are generally not conducted with any gas!
It's much too compressible, and the stored energy is high.
Pressure tests are usually done with water or another fluid with low compressibility.
Much less stored energy.
So if it fails, it fails with a phut, not a bang.
My father is the proud owner of a 1915 steamroller. Every spring he has his annual appointment with his boiler inspector. This starts with a visual inspection, using cameras and the mk1 eyeball, then progresses to a hydraulic test, where water is pumped into the boiler to a greater pressure than the normal maximum working pressure - usually about 20% over, I think. (I could be wrong with the 20%, it may be 25% or more!)
We make pumps here for the offshore oil and gas industry. All of our pressure casings are tested with water at 50% over rated pressure to ensure they won't go *phut* on an oil rig. I would imagine a boiler test at 50% is also quite reasonable.
Post by: yorkie on 27 November, 2018, 05:56:09 pm
Upon checking with t'father, he has confirmed that the hydraulic test is indeed 50% over normal working pressure. Turns out that my memory is faulty (not that that comes as a surprise!)Pressure tests are generally not conducted with any gas!
It's much too compressible, and the stored energy is high.
Pressure tests are usually done with water or another fluid with low compressibility.
Much less stored energy.
So if it fails, it fails with a phut, not a bang.
My father is the proud owner of a 1915 steamroller. Every spring he has his annual appointment with his boiler inspector. This starts with a visual inspection, using cameras and the mk1 eyeball, then progresses to a hydraulic test, where water is pumped into the boiler to a greater pressure than the normal maximum working pressure - usually about 20% over, I think. (I could be wrong with the 20%, it may be 25% or more!)
We make pumps here for the offshore oil and gas industry. All of our pressure casings are tested with water at 50% over rated pressure to ensure they won't go *phut* on an oil rig. I would imagine a boiler test at 50% is also quite reasonable.
When the boiler was originally built, (worth mentioning that this is the 3rd boiler this engine has had) the initial test was to double the intended maximum working pressure, as a one-off. Every test since is to 50% over - in his engine's case 250 p.s.i. initially, then 187.5 p.s.i. annually.
Post by: rogerzilla on 27 November, 2018, 08:35:21 pm
Post by: andrewc on 27 November, 2018, 09:11:57 pm
Post by: rogerzilla on 27 November, 2018, 09:32:14 pm
Post by: Brucey on 27 November, 2018, 10:30:29 pm
It seems to me that variations in seal thickness/wear might account for +/- ~1/4 turn or so.
cheers
Post by: Gattopardo on 30 December, 2018, 11:36:19 pm
I can't see that there is a problem as if you have the right grind and don't tamp the grinds, the screen is clear, the seal is good and the tube is clear then how is there an issue. Stuck a bolt in and stuck the pot on the stove. The valve has failed so openes and doesn't build enough pressure to force the water past the weighed top to make the creama.
Now to get a new valve, or might try an find a new o ring, as finding a new valve in the UK might be difficult and or very expensive. Postage being more than the valve.
Also there is no way to know if a valve has failed to closed rather than open....
Post by: T42 on 31 December, 2018, 09:40:33 am
Hmm. SO has two Bialetti moka pots and the valve always points towards me on both. It's not a 2-start thread as far as I know.
Good way to ensure that you notice when it fails.
Post by: rogerzilla on 31 December, 2018, 09:46:49 am
Post by: Gattopardo on 16 February, 2021, 12:38:16 pm
Bugger.
Post by: Quisling on 17 February, 2021, 12:22:17 am
*steps rapidly backwards after lighting blue touch paper*