Abstract:
A low differential pressure, gas flow system particularly for laboratory uses. It has a cylinder and piston connected at the ends of the cylinder to give double acting pumping of a gas for circulation to and from a reactor at accurate and surge-free rates. The piston is driven by a power cylinder and piston and there are valves actuated in synchronism with the power strokes to switch the end connections of the cylinder for the gas pumping action, without pressure surges.