Control the Flow of a Pump With a Back Pressure Regulator

Controlling the flow rate of a pump does not necessarily require a sophisticated PID control or an expensive flow meter. Many flow control applications need flow control that can react at high speeds. Other applications may be handling aggressive media that would require the use of an expensive flow meter. This video demonstrates how a back pressure regulator can be used to control the flow into a system from a non-positive displacement pump.
Non-positive displacement pumps include all types of rotating impeller pumps. These are often referred to as centrifugal pumps. These pumps have a flow versus pressure performance relationship where for any given pump output pressure there is only one corresponding flow rate that the pump will deliver. The trick is to be able to adjust the output pressure of the pump to set it at the pressure value that corresponds with the flow rate that you are trying to achieve. This allows the flow rate that the pump delivers into the system to be set simply by setting the back pressure regulator to the appropriate pressure. This does not work for all applications but it is a great advantage when high speeds are required, when a simple lower cost solution is called for, or where aggressive media makes the use of a flowmeter impractical.
The advantage of the Equilibar back pressure regulator includes the following:
*The Equilibar is pilot operated and may be controlled by an electronic air pressure regulator or be a manually adjusted regulator. The manual regulator may be remotely located for convenience or safety.
*The Equilibar is fast acting. It can be adjusted to a new pressure and hence a corresponding new flow rate in rapidly as it responds to its pilot pressure setting in milliseconds.
*The Equilibar has extremely high resolution to allow you to modulate the flow precisely. The Equilibar uses a patented direct diaphragm sealing technology that eliminates internal friction.
*The Equilibar also works well with high viscosity fluids and with shear sensitive fluids.
*The Equilibar design is extremely easy to maintain and rebuild with affordable parts.
*The Equilibar backpressure regulators can be manufactured from body material choices including stainless steel 316/316L dual cert, PVDF (Kynar), PTFE Teflon, PVC, CPVC, anodized aluminum alloy, and Hastelloy C7 and C276 alloys. Equilibar has manufactured regulator bodies from Titanium, Zirconium, Tungsten, and others at customer request to match their application parameters.
In this video we demonstrate that the flow rate from the pump is repeatable. This flow control repeatability allows you to come back to the same flow rate time and time again. To show this we set the pressure first at 50psig and observe the flow rate produced by the pump. We adjust the pump pressure to 65psig and see the pump output flow drop. We then return to 50psig and see that we also return to the same flow rate. We also demonstrate that once the flow rate is set that system changes downstream do not cause the flow set point to shift. This is demonstrated by adjusting the gate valve with blue handle downstream of the Equilibar back pressure regulator. The simulated changes in the downstream system are shown on a pressure gauge.
This video was recorded in the engineering laboratory at Equilibar's headquarters in Fletcher North Carolina USA. These Equilibar application video's are all shot in only one or two takes per scene. For this video I used a horse watering tank that I purchased at the local tractor supply as the water reservoir. The flow meter is an old Fisher-Porter magnetic flowmeter (magmeter) that Equilibar has used in our lab for years with high reliability. I bought the pump from McMaster Carr specifically to run these application tests and then shoot the video. It is a rotating impeller design made by Flotec, model FP4012-10. We couldn't get the factory to provide a pressure versus flow curve so we ran our own in our lab. This type pump is usually sold to residential well water systems but it worked great for our application testing.
David Reed (Operations Manager) is shown in the video. Keith Roberts (Engineering Technician) put the setup together and ran all the tests that validated the concept. Video is taken by David Bonyun of Asheville Video http://ashevillevideoproductions.com/ David is a real professional and readily works with us to produce the Equilibar series of application specific videos at a rapid pace.

You can find more details about pump flow control and flow control valves in general at our website: https://www.equilibar.com/application...

If you have any questions, please do not hesitate to give a call to one of the engineers at Equilibar. Thanks for watching.
Equilibar, LLC
320 Rutledge Road
Fletcher, NC 28732 USA
Ph (828)650-6590
[email protected]