Save with Auto-Ship

Get the product you need, exactly when you need it, delivered right to your door. No more searching for the right part number, we've got you covered. Plus, you'll save $$ on every order and shipping is on us. Learn more

Save Money

Free Shipping*

Choose Frequency

*Free Shipping available in the contiguous US

500 ML Inline RO Membrane Flow Restrictor (50 GPD)

Price $11.99 List Price Price $16.99 Save 29%
Availability: In Stock
Choose a quantity
  • 1Filter$11.99 
  • 3Filters Price $11.28 each
  • 6Filters Price $10.79 each
Use the 500 Milliliter Flow Restrictor with 50 GPD RO Membranes. The flow restrictor is used to create pressure throughout the reverse osmosis membrane element. The flow restrictor also maintains a desired ratio of reject flow (to drain) and permeate (product) flow. The 500 ML flow restrictor has the direction of flow and flow rate indicated on the restrictor.
Package Qty1
Used In BrandsTier1
Manufacturer's IdPFR402Q-500
Actual Size (in)4 inches (Length) x 7/8 inches (Width)
Fitting TypeQuick Connect
Fitting Size (inches)1/4 inch

Reduced Contaminants

The TIER1-PFR402Q-500 is comparable with the following part numbers



  1. The flow restrictor should be changed every time the reverse osmosis membrane is changed
  2. Be sure that you order the flow restrictor ML size to match your reverse osmosis membrane GPD. They must match to operate at the correct efficiency. For the 500 ML flow restrictor, the RO Membrane must be 50 Gallons Per Day
  3. These are inline capillary systems that install into the drain tube itself. Just cut the 1/4-inch drain tube and push the two ends of the tube into the flow restrictor
  4. If an inline flow restrictor is already installed, remove the old inline flow restrictor and insert the new inline flow restrictor
  5. Change your filters and membrane at the recommended frequency, and clean your system with a product like Sani-System SS96RO, an easy to use, pre-measured, reverse osmosis system sanitizer