Specific Steps of NF Membrane Loaded into FRP Pressure Vessels

Installation & Precautions

The RO membrane is installed in the same way as NF membrane.

Preparations

Before loading, make sure safety shoes, rubber gloves, safety glasses, pliers, silicone lubricant, clean rags, and glycerin are well-prepared.

Check the upstream feed pipe and remove dust, grease and metal debris from the pipeline. If further cleaning is required, chemical cleaning is adopted to clean the feed pipe and the pressure vessel to ensure all foreign matters are effectively removed.
Check the feed water quality. Before loading the NF membrane element, use pre-treated water to flow through the pressure vessel for 30 minutes. Meanwhile, check if the quality of water entering into the NF membrane meets the feed water requirements of the membrane elements. Check if there is any leakage in the pipeline.
Remove the end plate and thrust cone from the pressure vessel. You may refer to the product schematic diagram when removing.
Use fresh water to flush the opened pressure vessel, and remove dust and deposits. If further cleaning is required, prepare a mop whose head is equal to the inner diameter of the pressure vessels. Let the mop absorb 50% glycerin solution and drag it back and forth inside the pressure vessel until the inner wall of the pressure vessel is clean and moistened to facilitate the membrane element loading.
Before loading the NF membrane elements, make sure all parts and chemical agents for loading, dosing and pipeline systems are well prepared. In addition, make sure the pre-filter system runs smoothly.
Open the NF membrane package just before loading the element, otherwise, it shall be sealed in the original package for storage.

Element Loading (8.0" Element):

Determine the position of the brine sealing ring on the NF membrane element.

1

Take out the membrane elements carefully from the packing box. Check if the position and direction of the brine sealing ring on the membrane element are correct. It should be noted that the open section of the brine sealing ring shall be placed towards the feed water direction.

Load the NF membrane from the feed water end of the pressure vessel.

2

Place the end of NF membrane element without the brine seal ring horizontally into the feed water end of the pressure vessel and push the element until about 10 cm of the element length is exposed outside the feed water end of the pressure vessel. It should be noted that always load membrane elements into the feed water end of the pressure vessel.

Install the interconnector into the permeate tube of the NF element.

3

Install the interconnector into the permeate tube of the element. Before installing the interconnector, lubricate the o-ring seals on the interconnector with silicon lubricate, glycerin or qualified pre-treated water to facilitate the interconnector installation.

The connection between 2 NF membrane elements.

4

Take out the 2nd membrane elements carefully from the packing box. Check if the position and direction of the brine sealing ring on the 2nd element are correct. Hold the 2nd element carefully and make the interconnector on the 1st element insert into the the permeate tube of the 2nd element. Slide the 2nd element until about 10 cm of the element length is exposed outside the the feed water end of the pressure vessel. Push the 2nd element into the pressure vessel and hold it carefully so that the weight is not supported by the interconnector.

Install the thrust cone into the concentrate end of the NF membrane element.

5

Repeat step 3 and step 4 until all elements are loaded into the pressure vessel. And then turn to the concentrate end and install the thrust cone into the concentrate end of the 1st element.

Connect the adaptor with the end plate and secure with fastening nuts.

6

Check the O-ring on the adaptor connected with the membrane element carefully. Insert the end of the adaptor without the O-ring into the end plate (sealing board, sealboard rubber O-ring, pressure head) and secure with fastening nuts. Insert the end of the adaptor with the O-ring into the permeate tube of the element. Place the stopper around the pressure head, install the retaining ring on the stopper and secure the stopper with stop screws.

Load the NF membrane element into the FRP membrane housing.

7

Install the end plate on the feed water end the same way as install the concentrate end (without the thrust cone installation procedure). And then install the inlet plug.

NF membrane elements are loaded into various FRP membrane housings.

8

Repeat these steps, load NF membrane elements into every pressure vessel and connect all external feed water, concentrate and permeate pipes.