See step-by-step instructions; how to review your pump curve to ensure that the minimum 40psi is available during the automatic backwash sequence.
In this video we review a very simple and fundamental concept for the successful operation of your Forsta Self-Cleaning Filter.
Self-Cleaning Filters utilize system pressure to drive the automatic backwash sequence. Standard 90 and 180 series filters require a minimum of 40psi during this cleaning cycle.
Making sure that your pump is sized to provide a minimum of 40psi at system flow plus flush flow is critical to guarantee effective cleaning. On our graph with the sample pump curve the 40psi threshold is indicated with this magenta line.
In this example, we will review two flow rates against a sample pump curve, considering filters with a 1” flush valve.
Let’s begin with a system flow of 100gpm. When we add the 60gpm flush flow rate of the 1” valve to the system flow, we get 160gpm. We then draw a line from this value up to our pump curve, and as you can see we have 55psi of pressure at system flow plus flush flow.
If we consider a system flow of 200gpm, when we add the 60gpm flush flow we get 260gpm. Again, we draw a line from this value up to our pump curve, and see that we have only 30psi of pressure at system flow plus flush flow. This is insufficient pressure and means that the pump needs to be upsized for this system.
I hope this tutorial has been helpful for you. If your system uses a 1.5” or 2” flush, please refer to those tutorials.