In typical hose and tube extrusion applications, the speed of the material passing through the heating apparatus makes it more or less pliable. The amount of vacuum being applied to the tubing, while it is pliable, controls the O.D. (outer diameter) of the tubing.

In this application, the QB3 is controlling vacuum (from the source pump) directly through itself, by becoming the restriction in the line. The QB3 is a good choice because it offers a high flow rate and the vacuum level is usually pretty shallow, meaning the differential is small and flow potential is limited.

Proportion-Air often controls the vacuum in the chamber and the low pressure injected into the inside of the tube. This low pressure works with the vacuum to create uniform tube wall thickness, by creating the inner diameter and outer diameter of the tube or hose.

Hoses and tubing are used in several markets, especially medical, where they are used for everything from tying off wounds to ventilators and respiratory equipment.