Replacing Reverse Osmosis Membrane Elements - Occasionally, it is necessary to replace the reverse osmosis membrane elements of a system. This can be determined following troubleshooting and other remedial actions.

As with replacing O-Rings, the reverse osmosis system should be shut down and drained. Prior to installation, the new element serial numbers should be recorded indicating their intended location in the system. This is useful when comparing the membrane manufacturer’s test data against the actual system performance.

It may be necessary to remove both of the vessel end-caps. The elements can then be removed in their normal direction of flow. This will prevent their brine seals from jamming against the pressure vessel. The replacement elements can be inserted in the feed end of the vessel and used to push the other elements through.

The U-Cup brine seals and the inter-connector O-Rings can be sparingly lubricated with glycerin to aid fitting. Each inter-connector should have O-Rings installed. U-Cup brine seals should be installed only with the open groove of the seal facing the upstream end of each element (you should also take note of the flow arrow on the side element which points toward the downstream end). Never put brine seals on both ends of an element.

After element replacement is completed, any gaps should be limited with shims. The end caps can then be installed and the reverse osmosis system started. The system should be filled with low-pressure water prior to starting the high-pressure pump. Any new elements should be rinsed to drain to remove any residual preservative chemicals. System operating data should be collected after the plant performance stabilizes (this is normally within 24 hours).

Technical support and advice

Reverse Osmosis Chemicals International work closely with a diverse range of global organisations, intelligently combining advanced treatment technologies with practical solutions to resolve complex issues. If you have a project you would like to discuss, or you require technical support and assistance; or if you simply have a question about our reverse osmosis technology solutions please contact one of our specialist advisors using our Technical Support page or call us on +44 (0) 330 223 31 31.