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Thread: Input pressure

  1. #1
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    Input pressure

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Evening all

    Just wondering if there is a minimum and maximum inbound pressure For the average 2 grp commercial machine.

    Im redesigning one of my carts and looking at putting a pump into the header tanks to feed the machine.

    At present the onboard pump sucks it out of the tank underneath with no assistance, however im told if I can push water in I will extend the life of the internal pump.

    Thoughts? Tech document???

    Thanks
    Melbuurn

  2. #2
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    Re: Input pressure

    Anyone?

  3. #3
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    Re: Input pressure

    As I understand it, yes there is minimum and maximum water pressures that commercial machines are designed to run on, and the pumps are normally set to boost from mains pressure, but most can be adjusted to give nominal 9bars brew pressure from a lower inlet pressure, which is common in your situation.* The machine will often work outside the nominal pressure ranges, but not as well as it could.

    The most basic thing you could do is have your water tank a long way above the machine, then there is a small pressure differential, in the right direction, and gravity is free. (Might be possible if you are redesigning your cart?)
    Otherwise you would be looking for a pump that will operate from a container and supply a nominal mains pressure to your machine pump, but 2 pumps seems like an expensive/complicated way to go compared to getting your brew pump pressure adjsuted to suit your water supply arrangement.

  4. #4
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    Re: Input pressure

    thanks Bulitt

    I was simply trying to discover if I they handle 35psi, 40 psi, 17psi etc on the input side.

    Worst case scenario, I will just change the pressure valve on my little pump to only supply X pressure

    I guess a question would be - what is the average pressure that come out of a Melbourne tap ??


  5. #5
    Mal Dimal's Avatar
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    Re: Input pressure

    Gday Melburn... :)

    Yes mate, if youre thinking of installing a Water Feed Pump then it would be advisable to fit a Pressure Limiting Valve (PLV) downstream of the pump discharge.

    Also, if you havent already got one fitted, you should also think about installing a One Way Valve (Check Valve/Non Return Valve) upstream of the Rotary Pumps Intake - This is to ensure that the pump remains primed when the Water Feed Pump is turned off (or mains water pressure is removed).

    Mal.

  6. #6
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    Re: Input pressure

    Behmor Brazen - $249 - Free Freight
    Kiss is always best. :)

    If the machine in question is staying with the cart in question then time for some re arrangement of gear. There is no benifit to having one pump feeding another it just complicates the system and increases the chances of failure.

    Take the internal pump out of the machine and mount it down at tank level. Providing you drop a check (non return) valve between the tank and pump and start with the pump primed you wont have a problem at all. Just use a decent braided hose (to handle the 9bar+ pressure) to the machine and extend the power wires on the pump to make it external.



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