My Rio 2 Hx 2 group machine calls for an incoming water pressure of 22 PSI. I would like to work out of a water reservoir, but find that I am not achieving the desired pressure at the group heads upon dispensing a shot. The machine is not plumbed in, but rather drawing from a 5 gallon reservoir. In an effort to bring up the water pressure at the group had, I purchased a flojet 5000 system. Because the flojet system delivers a pressure of 30-40 PSI, I needed to place an in-line pressure reducing valve after the flojet, but prior to my machine. In the flojet manual however, it states that you cannot use a pressure reducing valve lest you void warranty on the flojet.

Is there pressure reducing valve that would take the excess pressure and divert back into the reservoir? I am thinking something along the lines of the bypass valve in the pump for my machine.
Thank you

I use the same Flojet as you to draw from a 5 gallon bottle of water to feed my machine. I added the Shurflo accumulator so I get the exact pressure I want, it comes precharged at 20 PSI. It is very easy to connect and produces a smoother water flow, less pulsing than the flojet produces by itself.

https://www.espressoparts.com/shurflo-accumulator-tank

Thanks so much! Exactly what I was looking for, but I didn't know it existed. One more question for you, if you did not use the Flojet, or the pressurized tank, does your machine produce the recommended 8 to 10 bars at the group head?
Thanks again, big help

Oh, I think you are confusing two different things. If you have a machine that has "line fed" preinfusion pressure, the preinfusion pressure is controlled by the pressure of the incoming water supply, in our case the pressure from the Flojet or the accumulator. But the brew pressure is not related to the water supply line pressure. The brew pressure is generated by the machine's pump, vibe pump or rotary pump in a pump machine (or by the pressure from the spring in the case of my lever).

What leads you to think your brew pressure is low?

Bak Ta Lo wrote:But the brew pressure is not related to the water supply line pressure.

Most rotary pumps have a simple bypass valve to regulate pressure, so the inlet pressure does affect the output pressure. From what I've read, those with a balanced bypass valve are less sensitive to input pressure (I've only adjusted those with a regular bypass valve).

Interesting, never encountered that arrangement. So that may be why the machine in question has the specific 22PSI input pressure requirement. In that case the accumulator could still be the solution, as it can be dialed in to give the required input of 22PSI.

While I know that this is not scientific, when I attempt to brew a shot, even if I release the portafilter, there is no built up pressure at the group head. Further, I have a gauge which reads dispensing pressure, it goes from 0 bar to 4 bar when I attempt to dispense a shot. I did order a gauge to attach to my portafilter head to double check that the main gaug is/is not working though. I have also replaced the pump already, and adjusted the bypass valve to allow for the maximum pressure available, it tops out a four bar.

Also, I have the accumulator tank on the way and will certainly post results as to whether or not this has helped anything as soon as it arrives. If there are any other thoughts, I would love to hear them. I am attaching an earlier thread detailing some of my pressure issues as well, thanks for your time and your thoughts:
Low dispensing pressure at grouphead- Rio 2 group espresso machine

kiley76 wrote:While I know that this is not scientific, when I attempt to brew a shot, even if I release the portafilter, there is no built up pressure at the group head. Further, I have a gauge which reads dispensing pressure, it goes from 0 bar to 4 bar when I attempt to dispense a shot. I did order a gauge to attach to my portafilter head to double check that the main gaug is/is not working though. I have also replaced the pump already, and adjusted the bypass valve to allow for the maximum pressure available, it tops out a four bar.

I wonder if the flojet output is just not capable of supplying the correct pressure for the machines rotary pump to work correctly. The accumulator will let you try the machines stated required pressure, as well as play around with other pressures by adjusting the accumulator's charge. I have been adjusting mine to test different PI pressures, it is a cool trick to have. Wait to see how it works for you.

Great, I still have plenty of learning to do regarding the pre infusion. Thus far comma I haven't yet used the flojet because it warns against the restrictor that I had planned on using.