Wunder-Bar Mark 4, Manual

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FLOW REGULATOR OVERVIEW 

The purpose of the flow regulator is to provide a more precise brix ratio between soda and syrup during pres-
sure fluctuations. The regulators compensate for pressure variances by automatically reducing the amount of 
product that passes through when pressure rises, and increasing amounts when pressure falls. Liquid flow 
regulators manufactured for post-mix beverage dispensers use a "piston" moving up or down within a 
"cylinder".  Typically, a small opening at one end of the piston is where the liquid enters. Located within the 
hollow piston is an adjustable tension spring which provides resistance against the path of liquid flow. 

HOW IT WORKS 

Incoming liquid, under pressure, forces the piston upward against the adjusted tension spring. As the piston 
moves, the regulating process begins. It partially or fully closes the outlet holes located in the top of the cylin-
der wall. As pressure varies, the piston will move in a direction to open or close the outlet holes to maintain 
the preset flow rate. 

FACTORY GUIDELINES 

The flow control regulator is not a "fix-all" for varying pressures over a wide range. There are limitations, a 
minimum operating pressure and a maximum operating pressure. This range is determined by the "Finished 
Product" (FP) flow rate. When you lower the FP flow rate, you increase the operating range. Therefore, a 
slower FP rate is generally better because lower pressures can be applied to the syrups and this increases 
the regulator's accuracy and consistency. To maintain a proper flow and desired "Finished Product (FP), flow 
rate must first be established. The following instructions will assist you in adjusting for a flow rate of 1.5 
ounces per second of finished product. 

CAUTION: 

Before you begin to set rates, make certain that all air has been removed from the soda, water 

and syrup lines. Air will cause varying flow. Also, be sure to chill all liquid to its normal operating temperature 
to assure proper settings. 

GENERAL OPERATING INSTRUCTIONS FOR FLOW REGULATORS 

Your Flow Regulator Manifold was factory pre-set and tested to the following pressures and flow rates: 

Achieving Finished Product Flow Rate of 1.5 Ounces Per Second  

1. Set High CO2 pressure to 90 PSI (flow) from the Carbonator 

2. Set Low CO2 pressure to 60 PSI (flow) for BIB pumps for Sugar-based syrups. 

3. Set Diet CO2 pressure to 20 PSI (flow) for BIB pumps for Diet syrups. 

4. Set the Soda flow rate to 6.5 ounces in 5 seconds (See adjustment procedures below)  

5. Set Syrup to Soda/Water ratio to 5:1 for most carbonated products.  Other ratios will be noted        

                 on the BIB label. However, some specialty beverages have 5.5:1 or higher ratios. Some juices and 
 

mixers have ratios as low as 1:1 to 2:1. Always read the BIB (Bag-In-Box) syrup container label 

for ratio specifications before starting. The small chamber (syrup side) of brix cup should fill to 1 

oz. in the same amount of time it takes to fill the large chamber 5 oz. of soda or water—confirming 

a 5:1 brix ratio (

Fig.5

). If the product was 4:1 ratio, the small chamber would fill to the same 1 oz. 

mark, but the soda or water would fill to 4 oz. Repeat until all products are properly brix ratio’d. 

At 1.5 ounces per second finished product flow rate, controllable pressure “throw” ranges are: 
 

SODA: 40 to 110 PSI 

SUGAR BASED SYRUPS: 20 TO 80 PSI 

DIET SYRUPS: 10 TO 40 PSI    

FLOW REGULATOR ADJUSTMENT 

Once the Soda and Water flow rates have been set, only adjust the syrup 
flow regulator adjustment screws if the ratio is not correct (

Fig.9

).  Loosen 

the desired syrup’s lock nut first, before attempting adjustments 

To decrease the amount of syrup: Turn the adjustment screw counter-
clockwise (

Fig.9

). 

To increase the amount of syrup: Turn the adjustment screw clockwise. 

Always make adjustments in 1/4 to 1/2 turn increments.   

MARK 4 MANUAL 

Fig.9 

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