Shown: Omicron 21300-10(H) PN16 316L for incoming pressure up to 230 psi, 400 gpm max flow, 10 micron, all 316L stainless
Here are the essential values you need to know in order to select an Omicron automatic screen filtration system:
- Pressure (psi) at filter inlet
- Maximum flow rate (gpm) through the filter
- Filtration degree -- most often 10 micron, sometimes 25
A minimum inlet pressure of 58 psi is required for reliable operation at 10 micron. Higher is preferable (details below). If pressure is below about 45 psi, 18 or 25 micron will be more reliable.
Note: In applications with incoming pressure below 70 psi, the filter is generally supplied with a flush line pump that boosts pressure during the backwash cycle, which is when adequate pressure is most critical to successfully suction collected particles off the screen.
Once the max flow rate and filtration degree are known, you can select the correct Omicron model based on the amount of screen area required.
- House pumps to roof tank, or constant pressure system.
If water is sent to a roof tank, it is simpler to determine max flow rate since it is limited by the max capacity of the house pumps, and how many will operate at the same time. The max flow rate of a constant pressure system can be more variable as it depends in part on overall fixture counts. However the max flow rate value is determined, it must be arrived at definitively in order to size filtration correctly.
- Filter before or after the house pumps.
Omicron technology is designed to operate at higher pressures, which enables the option of locating filtration after the house pumps. Up to 150 psi, no special build is required. Above 150 psi, we offer two versions: PN16 for up to 230 psi, or PN25 for up to 360 psi. High pressure capacities enable numerous options for locating filtration downstream of house pumps, even in very tall buildings. Consult us for more details.
- Is redundancy required?
Many projects today demand redundancy. For example, if the max flow is 400 gpm, the project may call for a twin parallel configuration in which either filter independently can accommodate 400 gpm if one were off-line. In this case, specify a twin system with twice the rated capacity (or nearly so) of the max system flow.
When deciding between 10 micron and 25 (coarser than 25 micron is of limited value for particle filtration in a domestic water application) keep in mind that a filtration degree is best thought of as percentage reduction of overall turbidity, not in absolute terms. It is not as if all particles larger than the specified micron size will be stopped, and all particles smaller will pass through. In the actual application, the difference between 25 micron and 10, with respect to its impact on turbidity reduction (impact on overall water clarity) is colossal. We recommend 10 micron unless circumstances (incoming pressure, available footprint or budget) do not permit.
- All 316L stainless or coated carbon steel housings.
Please contact us for more information or support in specifying filtration.