CVC™ Loop Description

The key principle behind the FMC series of controllers and related products is what we call the "CVC" mechanism. CVC stands for "Constant Volumetric Control". Below is a graphical description of the functional area of our controller. The figure below shows a representation of our Laminar Flow Element (LFE). The mechanical controllers do not have any electronic sensors but still have a LFE with the mechanical pressure-balancing loop around it.


The function of the balancing assembly is to maintain a constant differential pressure across the LFE or similar flow restriction regardless of inlet or outlet pressure (also regardless of whether the fluid is liquid or gaseous). Whenever there is a constant differential pressure across any type of flow restriction, there will be a constant volumetric flow (amount of volume transferred per unit time). This principle works for capillary, laminar, and orifice types of flow restrictions. The reason why we choose to use LFE©ˆs as opposed to an orifice is that the pressure-flow relationship is linear with respect to each other; as opposed to exponential as with an orifice. The end result of using an LFE is that we do not limit the pressure ranges or flow ranges that we can work with, such as the case with sonic nozzles or other types of critical restrictions.

The control loop schematic shows the control servo loops for our controller with and without electronics (i.e. a flow meter). With electronics, our controller can control mass flow and without electronics it can control volumetric flow or mass flow with constant outlet pressure gases or liquids. The FMC-series of devices will inherently and intrinsically control the volumetric flow or fluids without the need for sensors. The device is purely mechanical. The device will also work as fast as the fluid can act upon it; which can be in the tens of milliseconds. The FMC series of control loop, valving technology, and flow-metering technology is novel enough to have been issued a broad patent as well as several outstanding patents pending. Our development projects focus around industry specific alterations of the core technology; which bring new but conceptually fresh and simplistic solutions to users that can benefit by them.

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