A fluid control system for delivery of a fluid, comprising: a fluid flow path comprising an inlet valve configured for fluid communication with a fluid source and an outlet valve configured for fluid communication with a fluid sink; a chamber comprising a fluid-side chamber and a gas-side chamber, the fluid-side chamber and the gas-side chamber separated by a flexible membrane, the membrane configured so that there is substantially no pressure differential between the fluid-side chamber and the gas-side chamber across the membrane; the fluid-side chamber disposed on the fluid flow path downstream of the inlet valve and upstream of the outlet valve such that pressure changes in the fluid-side chamber are communicated to the inlet valve and the outlet valve; a pneumatically coupled drive in communication with the gas-side chamber configured to provide known incremental positive or negative volume changes that cause positive or negative pressure changes of gas in the gas-side chamber, and wherein said pressure changes in the gas-side chamber are communicated to the fluid-side chamber via the flexible membrane; a pressure sensor disposed to sense pressure of gas in the gas-side chamber; and a controller in communication with the pressure sensor to receive sensed pressure data and in operative communication with the pneumatically coupled drive, the controller configured to operate the pneumatically coupled drive to effect the delivery of the fluid using a plurality of the incremental volume changes performed as a series of discrete steps, the controller further configured to control the incremental volume changes responsive to a predetermined fluid delivery schedule. a fluid flow path comprising an inlet valve configured for fluid communication with a fluid source and an outlet valve configured for fluid communication with a fluid sink; a chamber comprising a fluid-side chamber and a gas-side chamber, the fluid-side chamber and the gas-side chamber separated by a flexible membrane, the membrane configured so that there is substantially no pressure differential between the fluid-side chamber and the gas-side chamber across the membrane; the fluid-side chamber disposed on the fluid flow path downstream of the inlet valve and upstream of the outlet valve such that pressure changes in the fluid-side chamber are communicated to the inlet valve and the outlet valve; a pneumatically coupled drive in communication with the gas-side chamber configured to provide known incremental positive or negative volume changes that cause positive or negative pressure changes of gas in the gas-side chamber, and wherein said pressure changes in the gas-side chamber are communicated to the fluid-side chamber via the flexible membrane; a pressure sensor disposed to sense pressure of gas in the gas-side chamber; and a controller in communication with the pressure sensor to receive sensed pressure data and in operative communication with the pneumatically coupled drive, the controller configured to operate the pneumatically coupled drive to effect the delivery of the fluid using a plurality of the incremental volume changes performed as a series of discrete steps, the controller further configured to control the incremental volume changes responsive to a predetermined fluid delivery schedule.