Variflo Pneumatic Conveying System is a unique development for controlled line loading of dense-phase pneumatic conveying systems. Designed for long distance conveying with the highest line loading for economical use of conveying air and lowest feasible material velocity. Variable line loading is achieved with a an outlet Dome Valve that is modulating its open position from signals indicating pipeline back pressure. The Dome Valve modulation regulates the allowable line loading for maximum effect for the available conveying pressure. This method of line loading is essential for automatic self regulating conveying efficiency when conveying distances are long. The modulation process prevents high back pressure from line overloading and also prevents loss of efficiency when the line is too lightly loaded. This is a unique macawber development that has not been repeated by others. No pipeline boosters are required which are unnecessary for a controlled low material velocity through the pipeline and would upset the auto line loading.This saves further maintenance and the cost of running air lines to the booster connections. The system design and components are subject to continuous development and improvement for lower product cost and performance.