RO Membrane Feed Spacer Data Sheet
This feed spacer data sheet covers the material, structure, thickness options and dimensions of the diamond-mesh feed spacer used in spiral-wound RO membrane element production.
- MaterialPolypropylene
- StructureDiamond mesh
- Thickness28–34 mil
- WidthTo element size
What the Feed Spacer Does
The feed spacer is an extruded diamond-mesh netting placed in the feed channel between membrane leaves. It holds the feed flow path open, generates turbulence that limits fouling, and sets the feed-side pressure drop across the element.
It is one half of the two flow layers in an element — see feed spacer vs permeate carrier for how it differs from the permeate carrier. Use the values below as a production reference and confirm exact figures for your order.
Feed Spacer Specifications
Typical specifications for RO membrane feed spacer. Exact values are confirmed per order.
| Property | Typical specification |
|---|---|
| Material | Polypropylene (PP); polyester (PET) on request |
| Structure | Extruded bi-planar diamond-mesh netting |
| Thickness options | 28 mil (0.71 mm), 31 mil (0.79 mm), 34 mil (0.86 mm); thicker grades for high-fouling feed |
| Strand geometry | Diamond pattern, symmetric crossing strands |
| Width | Cut to element leaf width (1812 to 8040) |
| Roll length | [Confirm per order] |
| Colour | Black / natural (typical) |
| Temperature compatibility | Suitable for standard RO feed conditions |
| Chemical compatibility | Good resistance to typical RO feed and cleaning chemicals |
Choosing Feed Spacer Thickness
Thickness is the most important feed spacer choice. A thicker spacer opens the feed channel, lowers pressure drop and resists fouling — but reduces how much membrane area fits in the element. A thinner spacer raises packing density at the cost of higher fouling risk.
Match thickness to your feed water quality and element design, then quantify the length you need with the feed spacer length calculator. For the full material set, see the raw material selection guide.
Thickness trade-off
- Thicker → lower ΔP, less fouling
- Thicker → less membrane area per element
- Thinner → higher packing density
- Thinner → higher fouling risk
- Match to feed water quality
The Wrong Feed Spacer Shows Up in Performance
Feed spacer is a low-cost component with an outsized effect on how the element runs. Getting the spec wrong is felt downstream.
High Pressure Drop
Too thin a spacer raises feed-side ΔP and energy cost across the system.
Faster Fouling
The wrong geometry traps solids and shortens cleaning intervals.
Rolling Problems
Inconsistent thickness disrupts winding tension and finished diameter.
Need feed spacer for your element production?
Tell us your element sizes and feed water conditions — we’ll recommend the right feed spacer thickness and supply it to spec.
Feed Spacer FAQ
What is an RO membrane feed spacer made of?
Feed spacers are typically made of extruded polypropylene (PP) in a bi-planar diamond-mesh structure, with polyester (PET) available on request. The mesh holds the feed channel open and creates turbulence to reduce fouling.
What thickness of feed spacer should I use?
Common feed spacer thicknesses are 28, 31 and 34 mil (0.71–0.86 mm), with thicker grades for high-fouling feed water. Thicker spacers lower pressure drop and fouling but reduce membrane area per element, so the choice depends on your feed quality and element design.
What is the difference between a feed spacer and a permeate carrier?
The feed spacer sits in the feed channel and carries feed water across the membrane, while the permeate carrier sits inside the membrane envelope and carries product water to the central tube. They are different materials and are not interchangeable.
How much feed spacer is needed per element?
The amount depends on the element size and number of leaves. Use the feed spacer length calculator to estimate the length required for a given element before ordering.