Draft System Principles Flashcards
(41 cards)
What gases are acceptable for use serving beer through a draft system?
Only CO2 and N2 or a blend of those gases
What is CO2 used for? What does it provide to the system?
CO2 pressure is applied to the draft system in a balanced way that maintains 1. proper carbonation 2. pushes the beer to dispense
What 3 factors need to be balance on a draft system to keep the system maintained?
Temperature, applied gas pressure, resistance
Why does a draft system need to operate under pressure?
As the beer moves through the beer line to the faucet, it works against resistance SO it needs pressure to maintain carbonation and push beer through the lines
What are the primary elements of the draft system that provide resistance to flow as the beer moves from keg to faucet?
Friction in the draft lines (dynamic), changes in elevation of the draft system (static)
Where does resistance come from?
Atmospheric Pressure (gravity) and friction from the beer lines
What two things need to be balanced in order to maintain a draft system?
Applied Pressure and Resistance
What determines Flow Rate?
Relationship
1. Applied gas pressure ** 2.Resistance** to flow out of the faucet determines flow rate
What should the temperature and PSi be set for an average draft system?
38* and 14.7 PSi (less at higher elevations)
What is “Flow Rate”?
Applied gas pressure pushing on the system versus the resistance to beer flowing out of the faucet -
1 gal per minute
How can you add pressure to a Long Draw system without over carbonating it? Why would this work?
Use CO2/N2 blend, because N2 does not dissolve into cold water based liquids like CO2
How can you add resistance to a Direct Draw System?
Use thinner gauge line with more footage use a jumper line
What are the gas ratio blends available for CO2/N2?
70/30 or 60/40, more CO2 than N2
What is the ratio for G-Mix or “Guinness Gas”?
25/75 - 25 CO2/75N2, pretty flat
What is an alternative to using N2 for a Long Draw System?
Beer Pump
What is the Primary Regulator used for?
Control of the flow of gas from the bulk tank to the system
What is the name of the device that allows for different pressured to be applied to individual kegs?
Secondary Regulator
What component is where the pressure side and beer side of a draft system come together?
Coupler
What is the name of the device that allows gas to flow in but seals so it keep beer from entering the gas line in the coupler?
Check Valve or Thomas Valve
When do you use Jumper Lines?
Long Draw System - connect couplers to faucets and connect trunk lines to faucet shanks
Direct Draw - use as a choker between main beer line and faucet
What is a FOB
When do you use it?
Foam on Beer - Used in a Long Draw System, it is a canister with a float in it that is attached to a beer line, when keg is empty, the float falls and seals inlet with dispensed gas, keeps line full of pressurized beer while keg is changed
What is a beer line made of? When do you use it?
vinyl, simple, flexible PVC, oxygen permeable
used in Direct Draw System
What is a Trunk Line?
What is a Trunk Line made of? When do you use it?
Polyurethane glycol tubing
Long Draw Systems, used for caring glycol not beer,
insulation to keep beer cool
What is another name for this Tubing?
What is Barrier Tubing?
used in trunk lines of a Long Draw System, designed to prevent the passage of oxygen and other contaminants into the beer line, and the leakage of carbon dioxide out of the beer
