Introduction

The Auper flow meter was originally design specifically to be used in draft beer. Three years of R&D were necessary to originally design this flow meter which has remained unchanged (and copied) since its release on the market in 1985. Auper was the first company to manufacture such a flow meter in North America. Tens of thousands are in use all over the world in all kinds of draft beer dispensers. It is used to monitor other products too, such as soft drink, juice, coffee, oil, water etc... We use standard Hex nut, washers and draft beer tailpieces to adapt to all plastic beverage tubing. The internal diameter of the tubing may vary from 3/16" (4.7mm) to 1/2" (13 mm). Tailpieces are available in chrome plated brass or stainless steel.

Operation

Liquid flowing into the flow meter (turbine) causes the propeller located inside the flow meter to spin. The internal diameter of the turbine and the design of the passageway allows a liquid to circulate normally, without cavitations or blockage. A flow meter is selected according to its typical flow rate specifications. At equal pressure, a liquid with a low viscosity (beer, water) flows more easily and at a faster rate within the same line than a thick viscose liquid like syrup. We are never concerned with the type of liquid we are measuring but by the speed at which it is dispensed. The Auper flow meter is made of Delrin for its durability, its low friction properties (close to Teflon) and extremely low absorption. It is covered with rubber to protect it from moisture and water. The flow meter does not require any power from the electronics it is connected too. An accidental short-circuit would not damage it. The signal generated by this flow meter is totally independent from the type of product it is measuring; viscosity or dark products would not block the passage of an infra-red beam for instance.

The Auper flow meter model 50-316 has an operating curve which was designed for standard draft beer dispensers. This model operates very well on beer lines with an internal diameter between 3/16" (4.76mm) and 3/8" (9.25mm) with an average flow rate between 1 and 2.5 oz/sec (1.5 and 4 l/min). Some products such as the Guinness beer or carbonated water are often running at slower speed and will require a model with a slower typical flow rate (50-018). Ask you Auper representative for guidance before you order.

Model	Application	Pulse/oz	ml/pulse	Typical flow rate
50-018	Guinness/Soft drink/Soda	30	1	1 Oz/sec	30 ml/sec
50-316	Draft beer/Wine/Soda	15	2	2 Oz/sec	60 ml/sec
50-332	Alcohol/Syrups	45	0.6	<>	<>
50-114	Fast flow applications	7	4.25	4 Oz/sec	120 ml/min

Installation

The flow meters are usually mounted in the storage room above the keg, on top of the wall bracket. It is inserted in the rigid tubing and secured to the wall using a plastic bracket when necessary. If FOB detectors (also called empty keg detectors) are used, the flow meter should be installed after this device. The FOB will prevent the flow meter from ever being in contact with foam or air rushing up the line.Each product line has to have a flow meter. Each flow meter is wired out of the storage room to either one of the Auper electronic controllers. Each flow meter is identified by line number, brand name and destination.

Beer Line Cleaning

The norms for beer line cleaning will vary from one country to another. Most beer line cleaners use a caustic solution (bleach) to clean and disinfect the lines and then rinse using soft water. The turbine should remain connected to the line in order to benefit from the line cleaning. When ever lines are cleaned, the meters should be read before and after or the system could be disabled by the manager. In certain countries, norms require that a sponge be used during the procedure. The turbine would have to be removed from the line since it will block the passage to the sponge or the sponge would block the flow meter. The company responsible for the line cleaning must be warned that flow meters have been installed in the beer lines and you must request that they use chemicals instead of sponges. Beer line cleaning should take place at least every 4 to 6 weeks.

Trouble shooting foamy draft beer

Draught beer is a sensitive product which requires a certain number of parameters to be just right :Temperature, pressure, propellant and good beer system design. The Auper flow meter (turbine) is guaranteed not to make beer foam. However, the installation of flow meters into your beer lines will not solve the foaming problems. It would only tell you how much is wasted. Before you proceed with the installation of the flow meters, take a good look at the dispenser itself and ask a few questions. Test the system in the morning before the bartenders start using it.

1. Does the serving temperature correspond to the brewers norms ?

North America: 38F(3.3C) & 42 F(5.5C)
Europe: 43F(6C) & 48F(9C)

Pour a glass and insert a thermometer immediately in the freshly poured beer. If the temperature in the glass is outside these norms, it is quite possible that your refrigeration system is defective or needs adjustment. Too high a temperature will increase the risk of excessive foaming. If too cold, the beer is not foamy enough and bartenders usually serve more in each glass. In either case, you should be concerned that the pour cost will probably be too high.

2. Is the flow rate between 2.5 and 3.5 l/min (Aprox: 2 oz/sec) ?

If the flow rate is too slow, it is probably due to a lack of pressure in the system. The C02 gas can separate from the beer while in the line causing the beer to foam at the tap. The color of the beer will change a few seconds after the tap is opened, passing from a clear and golden color to white. A gas leak will have the same effects.

3. Check the propellant ! Is the beer flat or over carbonated ?

Any beer system with a distance between the kegs and the faucet greater than 10 feet (3 meters) should be pressurized using a mixture of air or nitrogen (70 %) and CO2 (30 %). Straight CO2 can be used for direct draw systems and very short runs (less than 10 feet or 3 M). Clean straight air can be used if the sales volume per day is very high. Otherwise, it will either contaminate the beer (think of where the air is pumped from) or it will make the beer flat. The wrong choice of propellant will either make the beer foam, make it flat or change the taste. In either case you will be wasting product thus increasing your pour cost . Get a qualified technician to look at the problem !

Non-refrigerated kegs (Europe)

Temperature is one of the elements that will affect draft beer along with pressure, the type of gas, the line design and the product itself. When kegs are stored in a non-refrigerated room, an increase in the store room temperature will have an effect on the way the product pours at the faucet. The higher the storage temperature is, the more gas pressure will be required to dispense the beer properly. When kegs are kept in a cooler, the external temperature will not have an effect on the draft beer since everything is under a controlled environment. With this type of installation, pressure settings are often kept to a minimum. The smallest change in temperature will have an effect and may cause foaming. Before you proceed with the installation of the flow meter, check if you can dispense draft beer for 15 seconds with the beer retaining its golden color when coming out of the faucet. If after a moment, it turns white, the pressure is too low. Inserting a flow meter will only make things worse. Increase the pressure by 2 PSI (14 KPa) and try again. Repeat this procedure until you can pour beer properly for at least 15 seconds. When inserting a flow meter in the beer line, the additional friction may have to be compensated by increasing the pressure settings. Once the flow meter is in place, do the same test and follow the same procedure.

Soft drink and Juice

Pre-Mix
Whether it is wine, juice, or soft drink, if it's ready to serve it’s Pre-Mix. As with draught beer, one flow meter per line will be necessary.

Post-Mix
For Post-Mix dispensers you have the choice of measuring the syrups or the carbonated water. If you are only interested in the total amount of soft drink dispensed , you will only need one flow meter connected to the carbonated water line (soda).

1. Measuring carbonated water

The ratio of the mixture (or “Brix”) is usually the same or very close for all the syrups (5:1). By installing the flow meter in the carbonated water (soda) line you will register the total amount of soft drink served through the dispenser. Since one carbonator unit can feed multiple dispensers, it is possible to install the flow meter closer to the carbonator just before the line splits to each dispenser, to monitor the total soft drink dispensed . If you want to monitor each dispenser separately, then the one flow meter per dispenser is installed, after the split, closer to the dispenser.

2. Measuring syrups.

If you want to know the quantity of each flavor served, you will need to install a turbine on each of the syrup lines. For this application it is necessary to use the turbine with model number 50-032 (slower flow rate).