Installation and removal method tips for reverse osmosis membrane replacements

Installation and disassembly tips for reverse osmosis membrane replacement
Reverse osmosis membrane is the core component of water treatment, usually used for drinking water equipment, industrial water equipment, and sewage water reuse, usually use quartz sand filter, activated carbon filter, precision filter as a pre-treatment, reverse osmosis membrane element protection, reverse osmosis membrane service life is about 2 - 5 years, when the membrane water output is small, desalination rate is low, repeated scientific cleaning regeneration can not improve the situation. If the membrane element is replaced, the following precautions should be taken. If these precautions are not strictly observed, the membrane element or the operator may be harmed to different degrees, and the performance of the membrane element may not be fully utilized or personnel may be injured. Therefore, be sure to check the following precautions before operation and follow them strictly.

Membrane Element Installation Precautions

Note 1: When removing the membrane element from the package, be careful not to scratch the surface of the membrane element or your hands when using scissors or knives.
Reason: When using scissors or a knife to cut the bag, if you insert it too deeply into the bag, the surface of the membrane may be injured, and if you use too much force, the skin may be cut.
Impact level: Very high

Caution 2: The bag is filled with 1 % sodium bisulfite as a protective fluid, so be sure to wear protective glasses and gloves.
Reason: Since 1% sodium bisulfite is used as a protective fluid, open the package in a well-ventilated area. Be sure to wear eyeglasses and protective gloves when opening the package. In the event that the medicine accidentally gets into your eyes, wash them immediately with water and consult a doctor. In case of spillage on the body and clothes, wash with water immediately.
Degree of influence: No influence on the performance of the membrane, but some danger to human body.

Caution 3: Wet the sealing ring of the connection part with clean water or glycerin. Do not use any lubricants (petroleum-based, grease, petroleum jelly and detergents), gasoline, thinner, etc.
Reason: The material of the collector pipe is plastic, so if petroleum, grease, petroleum jelly and detergent (e.g., White Cat brand) are applied to it, it will cause the collector pipe to crack in a short period of time. The use of gasoline type and thinner is also strictly prohibited. Failure to do so may result in a serious degradation of membrane performance. When installing the membrane element into the membrane housing, use clean water or glycerin to wet the connection area and the sealing area for installation.
Impact: Very high

Caution 4: Handle the membrane element with care. Do not throw or drop the membrane element.
Reason: Damage to the membrane element caused by throwing or dropping the membrane element may affect the performance of the membrane element.
Impact level: Very high

Note 5: Prohibit the use of hammers to beat the barbaric installation.
Reason: This will lead to the rupture of the fiberglass shell, so it is strictly prohibited to use a hammer to beat the membrane element and install it savagely. In this case, it is difficult to ensure the performance of the membrane element.
Impact level: Very high

1 Preparation before installation of membrane element  
① Flush the system piping: If the system is brand new, flush the system piping sufficiently before installing the membrane to avoid debris, solvents, or residual chlorine coming into contact with the membrane element.
 ② Clean the Pressure Vessel: Clean the inside of the pressure vessel before installing the membrane element to prevent dirt or debris from being deposited on the outside surface of the membrane element. It is recommended that a sponge ball be soaked in a 50% glycerin solution and then scrubbed back and forth across the interior of the membrane housing with a suitable tool to clean the inside of the housing. During the cleaning process, please be careful not to scratch the inner surface of the membrane housing with the tool.

2 Membrane Element Installation Sequence
Be sure to install the membrane element in its corresponding pressure vessel.
① The membrane element is usually stored in a 1 % sodium bisulfite solution, and should be rinsed with pure water first.
② There is a thick water seal on the feed water side of the membrane element. Note that the seal is installed with the mouth open toward the upstream. The function of the thick water seal is to ensure that all raw water flows into the membrane element without bypass flow. The flow rate of the raw water itself will cause the opening of the thick water seal to seal tightly against the inner wall of the pressure vessel. If the sealing ring is installed in the opposite direction, the raw water cannot be hermetically sealed, resulting in a portion 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.
③ Confirm that the O-ring is installed in the designated position of the connection fittings. When installing, make sure that there are no scratches or attachments on the surface of the O-ring and the connection fittings. Be careful not to twist the O-ring for installation. If the connection fittings leak, raw water will enter the produced water, which will result in a drop 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 water, distilled water or glycerin to facilitate installation.
④ Remove the end plates on both sides of the pressure vessel to install the membrane element. Install the adapter on the thick water side (downstream) of the collector pipe of the first membrane element. Then push the membrane element in the direction of raw water flow and install it in the pressure vessel.
When several membrane elements are installed consecutively, the next membrane element should be prepared for connection with the connectors before the previous membrane element is completely in the membrane housing. At the same time, care should be taken not to allow the membrane element to come into contact with the edge of the pressure vessel to prevent abrasion, and try to push it into the pressure vessel in parallel.
⑤ After confirming the adapter connection of the pressure vessel, connect the end plate on the thick water side to the membrane housing. Refer to the instruction manual of the pressure vessel manufacturer for the connection method of the end plate.
⑥ After completing the installation of the end plate on the thick water side, the membrane element 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 end plate on the influent side. When installing the end plate on the influent side, care should be taken to measure the gap between the end plate and the adapter. If there is a gap, install a plastic (or other suitable material) spacer with an inner diameter greater than the outer diameter of the adapter with a thickness of 1/4“-1/8” until the end plate cannot be fully installed in place, then remove one of the spacers and install the end plate again. Please refer to the membrane shell manufacturer's instruction manual for the connection method of the end plate.

3 Disassembly of membrane element
① Remove the pipes around the pressure vessel and remove the end plates at both ends of the pressure vessel.
② Push the membrane element downstream from the raw water inlet and remove the membrane elements one by one from the concentrated water outlet side. Do not use hard metal rods when pushing out the membrane elements.
③ Please note that failure to observe the preservation method of the membrane element may result in changes in membrane performance.

Precautions for Storing Membrane Elements
Note 1: After cleaning the membrane element with water, soak it in a sealed plastic bag containing 1% sodium bisulfite. Rationale: Storing the membrane element in a contaminated state or drying it after use may affect the performance of the membrane element when it is reused. Impact Level: High
Precautions 2: Store in a dark place at 5 - 35 ℃. Reason: Storage temperature outside the range of 5 - 35 °C may affect the performance of the membrane element. Performance is not guaranteed in this case. Impact Level: High
Precautions 3: Avoid storage below 5 ℃ and strictly prohibit freezing of the membrane elements. Reason: Icing will affect the performance of the membrane element. This condition does not guarantee its performance. Impact level: very high