Preparation for the installation of reverse osmosis membrane elements

①Cleaning the pressure vessel: Before installing the reverse osmosis membrane element, the internal environment of the pressure vessel needs to be cleaned to prevent dirt or debris from being deposited on the outer surface of the membrane element. It is recommended to clean the inside of the membrane vessel by using a suitable tool to scrub back and forth inside the vessel after dipping a sponge ball into a 50% glycerine solution. During the cleaning process, care should be taken not to allow the tool to scratch the inner surface of the membrane housing.

②Flush the system piping: If the system is brand new, the system piping needs to be fully flushed before installing the RO membrane to prevent debris, solvents, or residual chlorine from coming into contact with the membrane element.

Installation sequence of reverse osmosis membrane elements

The membrane element must be installed in its corresponding pressure vessel.

①The membrane element is usually stored in a 1% sodium bisulphite solution and should first be flushed thoroughly with pure water.

② There is a thick water seal on the feed side of the membrane element, note that the seal is installed with the mouth open upstream. The function of the thick water seal is to ensure that all the raw water flows into the membrane element without bypass. The flow rate of the raw water itself will cause the opening of the thick water seal to be tightly sealed towards the inner wall of the pressure vessel. If the seal is installed in the opposite direction, the raw water cannot be sealed, resulting in part of the raw water flowing to the outside of the membrane element, which reduces the flow rate on the membrane surface and leads to scaling, thus shortening the service life of the membrane.

③Confirm that the O-ring is installed on the designated position of the connection fitting. When installing, attention needs to be paid to the O-ring and the surface of the connection fitting for any scratches or adhesions. Be careful not to install the O-ring with a twist. If a leak occurs in the connection fitting, raw water will enter the produced water and will cause a reduction in the quality of the produced water. When installing on the collector pipe, wet the surface of the O-ring and collector pipe with pure, distilled water or glycerine to facilitate installation.

④ Remove the end plates on both sides of the pressure vessel to install the membrane elements. Install the adapter on the thick water side (downstream) of the collector pipe of the first membrane element. The membrane element is then pushed in the direction of the raw water flow and fitted into the pressure vessel. When multiple reverse osmosis membrane elements are installed in succession, the next element is prepared for connection to the connection before the previous element is fully inside the membrane housing. Also take care not to allow the membrane element to come into contact with the edges of the pressure vessel to prevent abrasion and push it into the pressure vessel as parallel as possible.

⑤ After confirming the connection of the adapter for the pressure vessel, connect the concentrated water side end plate to the membrane housing for the operation.

⑥After the thick water side end plate has been installed, the membrane element unit should be pushed again from the inlet side to the thick water side to ensure that it is completely tightly connected. Then proceed with the installation of the inlet side end plate. When installing the inlet side end plate, attention should be paid to measuring the clearance between the end plate and the adapter. If there is a gap, install a plastic spacer 1/4"-1/8" thick with an inner diameter greater than the outer diameter of the adapter until the end plate is not fully seated, at which point remove a spacer and install the end plate again.

Removal of the reverse osmosis membrane element

① After removing the piping around the pressure vessel, remove the end plates from both ends of the pressure vessel.

② Push the membrane elements downstream from the raw water inlet and remove them one by one on the outlet side of the concentrated water. Do not use hard metal rods when pushing out the reverse osmosis membrane elements.

③If the storage method of reverse osmosis membrane elements is not strictly observed, it may lead to serious changes in membrane performance, so users need to pay full attention to this.