The present invention is a vacuum valve assembly that creates vacuum on demand. The assembly has a body with a fluid inlet port, a fluid outlet port, a fluid flow channel extending between the fluid inlet port and the fluid outlet port, a vacuum port, a low pressure channel extending between the vacuum port and the fluid flow channel, a sensing member receiving channel, the sensing member receiving channel extending between the fluid flow channel and the low pressure channel, and a flow occlusion chamber that intersects the fluid flow channel. There is a sensing member with a fluid flow regulation portion and a sensing portion. The sensing portion is adapted to be movably received by the sensing member receiving channel. The sensing member is movable from a closed position to an open position. When the sensing member is in the closed position the fluid flow regulation portion closes the fluid flow channel to the flow of fluids, and when the sensing member is in the open position the fluid flow channel is open to the flow of fluids. When fluids flow through the flow channel a low-pressure condition is created within the low-pressure channel.