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Bezerra BZ35 - first impressions.

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  • Bezerra BZ35 - first impressions.

    Well the BZ35 i purchased second hand on the for sale forum has arrived, i spent this morning plumbing it in and then fired it up.

    looks quite at home beside the La San Marco grinder, a little bit heath robinson with the drain hose for the moment and had to block it up a little due to not having quite the right fittings for the water inlet.

    had a problem with the pressure regulation on the boiler, but i seem to have repaired it and am just tuming it in.

    will post with more details as i get familiar with it and get some good brews happening.

    the first few coffees have been reasonable, good crema and ok flavour - it seems to be a very forgiving machine.






  • #2
    Re: Bezerra BZ35 - first impressions.

    [movedhere] Brewing Equipment (non-machine specific) [move by] Mal.

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    • #3
      Re: Bezerra BZ35 - first impressions.

      starting to get the bezerra tuned in, coffees this morning were pretty damn good.

      i have slowly been raising the boiler pressure and waiting to see if i have problems with the PRV lifting again.

      is it satisfactory to set the PCV to just below the point where the PRV lifts or should i install a pressure gauge on the boiler?

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      • #4
        Re: Bezerra BZ35 - first impressions.

        Why do you want to raise the boiler pressure? I have the BZ-40 and the gauges are very handy when youre adjusting the machine but after that not really required. If you could get a gauge to temporarily install it would take a lot of guess work out of what youre doing. My pressure relief valve is set at 1.5 Bar and at that setting its screwed right down against a spacing washer. I run the boiler around 1.1 Bar. Our machines are very similar in construction, the -35 is slightly smaller and obviously doesnt have the gauges.
        Pete

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        • #5
          Re: Bezerra BZ35 - first impressions.

          because, as i said, the PRV was lifting - so presumably the PCV was set at above 1.5 Bar, when i had rebuilt it and refitted it i started with the adjustment wound right out and i have been slowly screwing it in to increase the operating pressure - and making sure the PRV doesnt lift again.

          I can get a pressure gauge from work and fit it to the boiler, would it be better to get a PF with a gauge and set it that way?

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          • #6
            Re: Bezerra BZ35 - first impressions.

            different pressures you would be measuring. boiler around 1.3 bar, group around 9 bar.

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            • #7
              Re: Bezerra BZ35 - first impressions.

              Originally posted by 3B3D3029313D255C0 link=1231921987/4#4 date=1232026927
              because, as i said, the PRV was lifting - so presumably the PCV was set at above 1.5 Bar, when i had rebuilt it and refitted it i started with the adjustment wound right out and i have been slowly screwing it in to increase the operating pressure - and making sure the PRV doesnt lift again.

              I can get a pressure gauge from work and fit it to the boiler, would it be better to get a PF with a gauge and set it that way?
              Sorry youve completely lost me with what youre trying to achieve. Brewing pressure and boiler pressure are completely different and independent variables. Sorry if this is telling you how to suck eggs, but Im not sure what youre referring to by PCV?

              You set your boiler pressure by a pressurestat, and that should be around 1.0-1.3 Bar depending on your choice. Ive found my boiler OPV was screwed all the way in at 1.5 Bar relief. The OPV is a safety valve that does not open in normal use (the Bezzera incorporates an anti-vacuum valve in the same OPV, however thats obviously closed in operation)

              The brew pressure is set by the adjustment screw on the procon pump, and that is obviously set around 9 Bar give or take, your choice. The brew water OPV is set at 10 Bar and is not user adjustable. Again its a safety valve that opens when the water in the HX expands when the machine is idling.

              If you have access to a PF with gauge then yes use that to adjust the brew pressure. Adjusting the boiler pressure and checking the setting of the boilers OPV will be difficult to set exactly unless you can modify a pressure gauge to fit on one of the boilers fittings for testing.

              Hope that helps.
              Pete

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              • #8
                Re: Bezerra BZ35 - first impressions.

                thanks peter, yes i realised i am confusing myself with thinking the boiler pressure is directly related to the brew pressure.

                to use the same terms as you, the OPV was lifting and releasing pressure when the machine was on, so i stripped and repaired the pressurestat (the adjuster screw had a damaged head and was wound right in and seized), now I am attempting to adjust the pressurestat to the correct point, i have been slowly increasing it a quarter of a turn at a time and waiting to check the OPV doesnt lift again.

                My intention was that once it lifted the OPV to then back of the pressurestat half a turn or so.

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                • #9
                  Re: Bezerra BZ35 - first impressions.

                  here is a photo of the current result,




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                  • #10
                    Re: Bezerra BZ35 - first impressions.

                    ...and here is the pour....








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                    • #11
                      Re: Bezerra BZ35 - first impressions.

                      looks good there matey

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                      • #12
                        Re: Bezerra BZ35 - first impressions.

                        Hi, I think that is probably a pretty dangerous way to do it. I wouldnt be adjusting the pressurestat without knowing the actual pressure. your boiler pressure release could be set really high for all you know. Id for sure connect up a gauge to read boiler pressure if you can.

                        Damian.

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                        • #13
                          Re: Bezerra BZ35 - first impressions.

                          Yeah Im with Damian on this one, I think Id want a gauge on there. Adjusting the boiler pressure affects the brew temperature, not pressure, so you may be able to get some idea by letting the machine idle for a while until the HX water has fully equalised with the boiler pressure, then hitting your brew button and seeing how active the water is when it comes out. If it spurts and slutters like crazy for a full 60-70 ml then its too hot, no spluttering at all and its probably not hot enough. However thats a seriously rough way to guess and would be no way to set the OPV. Keep in mind this is a safety device youre adjusting and the power of steam has to be seen to be believed if something lets go. Alternatively an infrared thermometer on the lower half of the boiler MAY give an indication (boiler pressure and temperature are directly related and can be converted) but of course I dont know if you have access to one? Just the same, I dont know, its all a bit dodgy in my mind and I seriously think getting hold of a gauge will be your best bet. Just think of how much money youve saved by overhauling it yourself  

                          BTW when you stripped the pressurestat did you fit an overhaul kit in it? Very cheap, easy to install and basically essential unless the PS was basically brand new. Available from Coffeeparts

                          Pete

                          Edit: I just re-read your post and saw how you intend setting the OPV (half a turn over operating pressure). You may find thats too close. The pressurestats are supposed to be accurate, but theyre not. Youd probably find having the boilers OPV set so close to operating pressure would have it releasing all the time and will both drive you nuts (mine leaked for a while and that was bad enough) and is probably not good for its seal. Theyre supposed to remain closed in normal operation and just get tested periodically by pulling on the stem with a pair of pliers

                          Edit#2 I just tried an infrared thermometer on my boiler and wasnt able to get any sort of consistent reading off it for some reason. Not sure quite why, but it was a dodgy way to set pressure anyway, so maybe it was trying to tell me something ;D

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                          • #14
                            Re: Bezerra BZ35 - first impressions.

                            ok, well the boiler looks to have a blank plug on an outlet, so i can probably fit a pressure gauge on that, as per your detailed post i dont think i am far off the mark anyway - firstly it makes a pretty damn fine espresso, secondly there is only spluttering for a little bit and then running nice and evenly.


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                            • #15
                              Re: Bezerra BZ35 - first impressions.

                              As far as setting the OPV I couldnt suggest relying too much on the espresso quality as an indication of where youre at with boiler pressure. To give you an indication, the difference between a boiler gauge pressure of 1.0 Bar and 1.5 Bar is a temperature difference of only 7 degrees. By the time thats converted to a temperature at the heat exchanger, THEN a temperature at the puck, how long you flush, etc etc I think you can see it will make very little difference.

                              By all means, once youve got the machine set up and youre used to it then you may want to play with your boiler pressure to tweak it, but thats a whole different era to overhauling and setting the OPV. At the moment this is the coarse adjustments, and the tweaking is later by taste. The pressurestat screws do need to be turned quite a bit to adjust however, so you may well have it pretty much right, but without a gauge its just guessing.

                              If the blank plug doesnt work, the other one you could try would be the steam outlet as thats just a hole in the top of the boiler.

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