Modify Tub/Shower Valve Port Size

Discussion in 'Showers and Tubs' started by ddocfletcher, Jul 26, 2013.

  1. Jul 26, 2013 #1

    ddocfletcher

    ddocfletcher

    ddocfletcher

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    Greeting's, I have a Kohler 11748 bath/shower valve which with built in diverter. I was planing to install it with the tub port to the shower and shower port to the tub. This was to make the water go to the shower without pressing the diverter. However shower port hole is smaller than the tub port hole. I'd like to know if I increase the smaller port hole size will I get more water out of it?
     
  2. Jul 26, 2013 #2

    AQualityPlumber

    AQualityPlumber

    AQualityPlumber

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    You'll probably get more flow to the head but your head will restrict the flow.
     
  3. Jul 27, 2013 #3

    ddocfletcher

    ddocfletcher

    ddocfletcher

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    That's fine. My purpose is to use the tub port for the shower head and drill the shower head port hole larger so the tub will fill at the full 5 gallon per minute.

    Doing this will make it so when the water is turned on it will go directly to the shower head instead of the tub. So to fill the tub the diverter will need to be pushed in.

    So will increasing the shower port hole allow full flow to the tub?
     
    Last edited: Jul 27, 2013
  4. Jul 28, 2013 #4

    AQualityPlumber

    AQualityPlumber

    AQualityPlumber

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    I would imagine it would. Larger the port, the more flow. I am not sure if you will get more flow out of the cartridge though. If it is a modern cartridge it will have plastic ports for the water to flow through. Drilling out the valve body will increase gpm but the cartridge may still restrict your flow.
     
  5. Jul 29, 2013 #5

    ddocfletcher

    ddocfletcher

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    Thanks for getting back to me. It is a kohler 11748ks. All brass, made for shower head (Main Port) and hand shower (Secondary Port). So I am hoping making the secondary port hole the same size as the primary I will be able to use it as a tub filler.
     

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