Cheers Eric, I will use some tape as well, I will also be getting some flare wrenches! I would post a pic of the remains of the pstat stuck in the brass fitting but its too embarrassing, I cant salvage the pipe unfortunately and the plastic isnt coming out!
Richard On Friday, February 14, 2020 at 2:39:34 PM UTC, Eric Christoffersen wrote: > > I had my first pstat rot on my b2. the plastic was impossibly fragile and > crisped into dust when i tried to remove it. I had to use a pick to clean > the plastic out of the brass threads. > > I use teflon tape when reinstalling. I have some good flare nut wrenches i > use whenever possible. > > Not sure what you mean about it being stuck. > > >> >> On Feb 13, 2020, at 09:56, Rich <[email protected]> wrote: >> >> thanks so much for the detailed reply! As you said this is great info so >> i am glad you left both parts up. I obviously need to work on my spanner >> technique as I havent seen any others have this issue, its actually quite >> hard to find the bit of pipe required. As the machine has 2 switches, one >> for on and the other for steam I presumed that on would still heat the brew >> boiler. I think following your reply it is safer if I just wait for the >> brass pipe! >> >> thanks >> >> Richard >> >> On Thursday, February 13, 2020 at 5:25:47 PM UTC, bmacpiper wrote: >>> >>> Well crap—I somehow read “OPV” in your question, instead of "p-stat". So >>> I wrote up this whole response before realizing that. I’m going to go ahead >>> and leave it, since the discussion might be helpful to someone else down >>> the road. But your basic questions are also answered later in the email. >>> I’m assuming you have a failed p-stat, which means it’s not a big deal if >>> you damage the old one on the way out. >>> >>> Best and talk soon, >>> bmc >>> >>> ----------------------- >>> >>> >>> Hi again Richard, >>> >>> A couple of things you’re saying don’t add up, so I want to clarify. In >>> fairness, I have a B2, so things may have changed. >>> >>> On my machine, the OPV (over pressure valve) is not a plastic part. The >>> p-stat (pressure stat) is a plastic part, however. >>> >>> Forgive me if I’m telling you things you already know, but here’s how it >>> sorts out: >>> >>> —The OPV is located behind the drip tray, on the right as you face the >>> machine, and may have a sticker over its access hole that says “do not >>> adjust” or similar. The adjustment screw is a large slotted screw, and is >>> used to adjust the maximum pressure to the brew boiler when pulling a shot >>> or backflushing. When that pressure is reached, water is shunted back to >>> the water tank (pour over machines) or into the drip tray (plumbed >>> machines). Note that this is not a safety mechanism; it’s used only to set >>> brew pressure to 9 bar or whatever. On top of the brew boiler is an over >>> pressure device that protects the pressure vessel from exploding, in case >>> something goes wrong with the OPV and/or logic controller. If this >>> activates, it will sound like a freight train coming through (loud hiss) >>> and there will be condensation all over the inside of the machine. A good >>> time to unplug, dry it all out, and figure out what the hell went wrong. >>> >>> —The p-stat is inside the machine, sitting atop a copper tube, and is >>> typically a black plastic device with 3 wires attached. This is how you >>> adjust the pressure to the steam boiler (I set this to about 1.45 bar). >>> Power goes to the steam boiler, and when 1.45 bar is reached, the p-stat is >>> switched to allow power to the brew boiler instead. When you hear “steam >>> boiler has priority”, this is the part that controls it. Since it is a >>> direct open connection into the steam boiler, the threaded interface >>> between the copper tube and the plastic p-stat must be able to seal against >>> 1.45 bar or more, and thus will not use grease, etc. to lube the threads. >>> >>> —In the case of both the p-stat and the OPV (and all other threaded >>> connections that have to be sealed), Expobar uses a food-grade sealant on >>> the threads. It is very thin, and dries almost instantly if the parts are >>> hot. If you use it to re-assemble things, you have to work very quickly, as >>> you usually only have a few seconds to get things tight and oriented >>> correctly. This sealant is very strong, and when removing parts that are >>> sealed with it, it definitely feels like you’re going to strip threads. >>> I’ve spent many hours of my life with a wrench in hand, and breaking this >>> sealant loose always makes me nervous, but I have also never stripped any >>> threads on the machine due to the sealant. I will say that it is >>> exceptionally important to use good technique. The best is if you have two >>> open-end wrenches, one for each side of the joint, that are both very well >>> fitted to the nuts. Try to have them aligned so that they are as close to >>> each other as possible, and then offset by maybe 15 degrees, and just >>> squeeze them together to break the part/nut/etc. loose. If you try to have >>> one in each hand, you will inevitably smear the corners of the nut/part and >>> then have a tough job ahead. If you only use a wrench on one side of the >>> joint, you will almost certainly twist the soft copper pipe and crimp it >>> shut, beyond repair. >>> >>> Be sure to use a brush (brass, for example) to gently clean all the old >>> sealant off the threads. It will seem almost fragile and tends to flake out >>> quite easily. I have had success using the sealant from Expobar/WLL, but >>> have also used yellow teflon tape on many parts (heating elements, p-stat, >>> OPV) with no leaks. It’s not what Expobar calls for but does work, and much >>> easier disassembly in the future as needed. >>> >>> —As to your question on whether the brew boiler can be used without a >>> p-stat, the answer is “sort of”. Since the steam boiler has priority, you >>> would have to jumper power to the brew boiler if you’re not letting the >>> steam boiler come up to temperature. One workaround when the p-stat sticks >>> (and never lets the brew boiler heat) is to reverse the power out wires on >>> the p-stat that go to steam and brew. This basically gives the brew boiler >>> priority, and since the steam boiler never heats and hits 1.45 bar, power >>> never switches over to it. The obvious problem with this scenario is that >>> the brew boiler gets power continuously, until its over-temp sensor on top >>> activates and cuts power to it. You may have the over pressure device on >>> top activate before that over-temp sensor activates; I just can’t recall. >>> If memory serves, the logic board (giemme and/or PID) will also be >>> monitoring temp in the brew boiler and only sending bursts of power if the >>> boiler is not up to set point yet, so that’s further protection. Either >>> way it’s outside of design specs, and not something I’d do as a permanent >>> fix. >>> >>> OK, hope this helps and talk soon. >>> b >>> >>> On Feb 13, 2020, at 01:30, Rich <[email protected]> wrote: >>> >>> Hi All, >>> >>> apologies for a spate of questions, again I have had a search but cannot >>> find anything. Has anyone else had the issue of the PStat getting >>> physically stuck in the brass fittings? I cant remove it so have had to buy >>> a new pressure pipe which isnt in stock until the end of the month from a >>> company in France (open to suggestions for UK suppliers?). Do people use >>> grease or any kind of lubricant to make sure these don't get stuck in the >>> fittings, it seems a tight fit and quite easy to shred the plastic? My >>> other question is whether I can use the brew boiler without a PStat, I >>> guess I can and that its only for the steam boiler but I wanted to check in >>> case I missed something! >>> >>> Thanks again >>> >>> Richard >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Brewtus" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/brewtus/468d7892-12c5-43ad-8506-520fb5d8fdfe%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/brewtus/468d7892-12c5-43ad-8506-520fb5d8fdfe%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >>> >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "Brewtus" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/brewtus/7c477aec-94ab-4ae6-92f7-d386eaa2049b%40googlegroups.com >> >> <https://groups.google.com/d/msgid/brewtus/7c477aec-94ab-4ae6-92f7-d386eaa2049b%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> >> >> -- You received this message because you are subscribed to the Google Groups "Brewtus" group. 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