Reverse Osmosis InLine Quick Connect Flow Restrictor
This sale is for one (1) Reverse Osmosis Quick Connect InLine Flow Restrictor (your choice of one - 300ML or 400 ML or 450 ML or 500 ML or 10000 ML). This flow restrictor is to be installed in the drain tubing. The restrictor has 1/4 inch Quick Connect fittings.
A flow restrictor will create back pressure on the membrane and allow the membrane to produce purified water to be delivered to the storage tank. Flow restrictors are sized to match the flow with the size of the membrane.
In selecting a flow restrictor, be certain you do not "under size" the restrictor as you will prematurely foul the membrane. If you "over size" the restrictor, you will be wasting water but not causing damage to the membrane.
Flow Restrictor Capacity
GPD to Drain:
300 ML - 114 Gal./24 Hours
400 ML - 152 Gal./24 Hours
450 ML - 171 Gal./24 Hours
500 ML - 190 Gal./24 Hours
Manufacturers of Reverse Osmosis Systems vary in their recommendations for selection of the size of flow restrictor to be matched with the various capacity RO membranes.
Filmtec, by far the largest manufacturer of Reverse Osmosis membranes, suggests a ratio of 1:2 or 1:3 or 1:4. They leave the final decision on sizing of the flow restrictor (to match the RO membrane) for the manufacturer. Correspondingly, one manufacturer may select a 20% (1:4) flow restrictor and the next RO manufacturer may select either a 25% (1:3) or a 33% (1:2) flow restrictor for the same capacity RO membrane.
Lets say that you have a 50 gallon per day RO membrane and you need to replace your flow restrictor. If you elected to use the 1:2 ratio, you would select the the 300 ML flow restrictor (50 gpd RO water to 114 gpd drain water - very close to the 1:2 ratio). However, if you elected to use the 1:3 ratio, then you would select the 400 ML flow restrictor (50 gpd RO water to 160 gpd drain water - very close to 1:3 ratio). If you want to use the 1:4 ration then you would select the 500 ML flow restrictor.
This example for the 50 gpd RO membrane can be used for any size membrane by just substituting your size membrane into the formula instead of the 50 gpd. Then selecting the ratio of your choice. We generally recommend a 1:2 or 1:2 and a half ratio.
Using the 1:2 ratio - 50 gpd RO membrane: times 2 = 100 gpd, therefore you would select the 300 ML flow restrictor.
Using the 1:3 ratio - 50 gpd RO membrane: times 3 = 150 gpd, therefore you would select the 400 ML flow restrictor.
Using the 1:4 ratio - 50 gpd RO membrane: times 4 = 200 gpd, therefore you would select the 500 ML flow restrictor.
To determine the flow restrictor for your system, first select the ratio. Next you would insert the gpd of your RO membrane in the formula instead of the 50 gpd and then multiply to get the gpd for the flow restictor which would be best for your system.
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