A regulator apparatus for distributing a fluid, the apparatus comprising: a charging valve assembly comprising an inlet for receiving a feed flow of the fluid, a first charging outlet for discharging a recharge flow of the fluid, and a valve movable between an open position in which the inlet and the first charging outlet are connected in fluid communication, and a seated position in which flow between the inlet and the first charging outlet is blocked; and a flow multiplier assembly comprising a first cylinder having a first bore cross sectional area, a first piston arranged within the first cylinder, a second cylinder having a second bore cross sectional area that is greater than the first bore cross sectional area, and a second piston arranged within the second cylinder, the first and second pistons (206, 210) coupled together and movable in a first direction towards an endwall of the first cylinder and a second direction towards an endwall of the second cylinder, the first cylinder comprising a first port for receiving the feed flow of the fluid, the second cylinder comprising a second port connected in fluid communication to the first charging outlet for receiving the recharge flow of the fluid, and an outlet for discharging an outlet flow of the fluid, wherein, in a recharge mode, the valve is in the open position, and the fluid is received in the second cylinder, causing the first and second pistons (206, 210) to move in the first direction, and wherein, in a purge mode, the valve is in the seated position, and the fluid is received in the first cylinder, causing the first and second pistons (206, 210) to move in the second direction, and discharging the outlet flow through the outlet. a charging valve assembly comprising an inlet for receiving a feed flow of the fluid, a first charging outlet for discharging a recharge flow of the fluid, and a valve movable between an open position in which the inlet and the first charging outlet are connected in fluid communication, and a seated position in which flow between the inlet and the first charging outlet is blocked; and a flow multiplier assembly comprising a first cylinder having a first bore cross sectional area, a first piston arranged within the first cylinder, a second cylinder having a second bore cross sectional area that is greater than the first bore cross sectional area, and a second piston arranged within the second cylinder, the first and second pistons (206, 210) coupled together and movable in a first direction towards an endwall of the first cylinder and a second direction towards an endwall of the second cylinder, the first cylinder comprising a first port for receiving the feed flow of the fluid, the second cylinder comprising a second port connected in fluid communication to the first charging outlet for receiving the recharge flow of the fluid, and an outlet for discharging an outlet flow of the fluid, wherein, in a recharge mode, the valve is in the open position, and the fluid is received in the second cylinder, causing the first and second pistons (206, 210) to move in the first direction, and wherein, in a purge mode, the valve is in the seated position, and the fluid is received in the first cylinder, causing the first and second pistons (206, 210) to move in the second direction, and discharging the outlet flow through the outlet.