Whether you are tapping beer on tap at home with a dispensing system or in a commercial setting with a more complex system, a beer regulator is an important part of the dispensing system. What are pressure regulators? The contents of CO2 and nitrogen gas tanks are under extremely high pressure. The main function of a regulator is to reduce this pressure to a safer, more usable level before the gas reaches the keg. The regulator is also responsible for maintaining the optimum carbonation level of the beer on tap.