What is Flow Restrictor?
A flow restrictor, as the name suggests, restricts the flow of RO reject water.
The flow restrictor maintains high pressure inside the RO membrane (a precondition for RO purification) by creating back pressure on the membrane and also controls the recovery ratio of the purifier.
If the flow restrictor is not used then the high-pressure water coming in from the booster pump will flow unrestricted from the reject outlet of the RO membrane.
This will result in low pressure inside the RO membrane and higher wastage of water. RO membrane won’t be able to work if the pressure inside the RO membrane is not high.
How to Find a Matching Flow Restrictor?
The ratings that you see on flow restrictors, like FR 200, FR 300, FR 450, indicate the flow rate, in mL per minute (Millilitres Per Minute).
RO membrane capacity is given in GPD (Gallons Per Day).
1 Gallon is approximately equal to 3.78 litres.
Generally, the flow restrictor value should be 4 times the production rating or the capacity of the membrane.
In order to find a matching flow restrictor, first, we need to convert the flow restrictor’s capacity value into GPD.