Preparatory work before installation

(1) When directing pretreated water to the reverse osmosis unit, ensure that the piping system and pressure vessels are free from dust, grease, metal residue, and other impurities to prevent membrane elements from being contaminated by foreign pollutants. Using a rotary brush and rinsing the pressure vessel with pretreated water is the most effective method.

(2) Inspect the influent water quality and rinse the system with qualified pretreated water for approximately 30 minutes.

(3) Remove the end cap of the pressure vessel, inspect the inside of the pressure vessel, and determine if mechanical cleaning is required.

(4) Install the permeate adapter with O-ring into the permeate port on the concentrate side. Glycerin or dioleate can be used for lubrication.

(5) Install the end cap on the concentrate side according to the pressure vessel manual.

(6) Prepare necessary components: concentrate seal, O-ring, open permeate adapter, closed permeate adapter, permeate connecting pipe, permeate pipe cap, etc.

Installation of reverse osmosis membrane elements

(1) Remove the membrane element from the plastic packaging in the carton

Note: When opening the plastic bag, it is best to cut an opening at one end. After removing the membrane element, save some intact plastic bags for storage when the membrane element needs to be stored in a bag.

(2) Install the "O" ring on the membrane element adapter. Apply some glycerin during installation and carefully install to prevent the "O" ring from being scratched. Also apply glycerin to the inside or outside of the membrane element permeate pipe.

Note: Do not use cationic detergents, edible oil, etc., as lubricants, as this may cause irreversible damage to the reverse osmosis membrane element.

(3) Apply glycerin to the concentrate seal and carefully install it in the annular groove on the inlet side of the membrane element as shown in Figure 1.

Note: The concentrate seal must be properly installed, otherwise, the actual recovery rate of the membrane element may be higher than the design value.

(4) According to the direction of the arrow on the surface of the membrane element, gently push it into the pressure vessel. After two-thirds of the membrane element enters the pressure vessel, insert the adapter onto the permeate pipe on the inlet side of the membrane element, as shown in Figure 2.

(5) Connect another membrane element to the exposed permeate adapter. After connecting tightly, gently push it into the pressure vessel. After two-thirds of the second membrane element enters the pressure vessel, repeat the above operation to install the next membrane element.

(6) When the last membrane element in the same pressure vessel is installed, insert a closed permeate adapter or a permeate pipe plug into the inlet end of the membrane element, see Figure 4.

(7) After installing the inlet permeate adapter, install the end plate of the pressure vessel. Check that the distance between the permeate pipe plug and the end plate is less than 5 mm.

Note: If the distance between the permeate pipe plug and the end plate is greater than 5 mm, excessive movement of the reverse osmosis membrane element during system start-up and shutdown may cause misalignment or damage to the O-ring or concentrate seal, resulting in a decrease in permeate water quality. Therefore, a gasket needs to be installed between the two.

Installation precautions:

(1) The membrane element is stored in a 0.05% to 0.1% sodium bisulfite solution. Pay attention to protecting your skin and eyes during installation:

(2) Save some packaging materials for temporary removal or storage of the membrane element:

(3) Number each pressure vessel and record the position of each membrane element according to the correct order of the elements in the pressure vessel. The record should be updated according to the installation of new elements and changes in element position:

(4) In order to avoid damage to the element, be sure to handle it carefully during installation, keep the outside of the membrane element clean, and only touch the element with clean hands or gloves.

Inspection after filling membrane elements

(1) Water flow confirmation

Carefully check whether the pipe fittings are correctly connected and the screws are tightened, and then conduct a water flow test, allowing the water pressure to rise slowly.

(2) Adjust operating conditions

Closely monitor the feed water and permeate water volume while adjusting the specified permeate water volume and recovery rate. If there is no loss or other problems, let the system continue to run in this state for one hour.

(3) Check permeate water quality

Sample the permeate water quality (conductivity) of each membrane module to check the permeate water quality. If there is an abnormal water quality membrane module, please re-confirm the O-ring, concentrate sealing ring, etc., and replace the defective parts.

(4) Initial operation record

The initial operation record of the system is very important, it is the basis for the analysis and judgment of system failures in the future.