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FRP Membrane Housing Installation, Disassembly, Maintenance

FRP membrane housing user's guide

Danger! High Pressure Device!

Please read the application guide carefully, any errors in the operation are likely to destroy the membrane housing, causing bodily harm and even life threatening.

Before having any operation to the pressure vessel, please read the "Application guide" carefully and conduct correct operation according to the regulations of guide.

Wrong installation of membrane housings or use rusty membrane housing components will seriously affect the sealing performance of the pressure vessel, and leave a security risk.

We suggest by has rich experience engineer to carry on the assembly, debugging, maintenance work to the pressure vessel.

Product Guide

8" FRP pressure vessel.

  • Connection type: end port or side port.
  • Available pressure type: 150, 300, 450, 600, 800, 1000, 1200 psi.
  • Length type: 1-7 core.
  • Color configuration: white as the standard color, also provide other optional colors.
  • Receive special specifications customized production.
  • Shell leakage test: water pressure test.
  • Test pressure: 1.5 times design pressure.
  • Allow operating temperature range: -7°C - 49°C.

4" FRP pressure vessel.

  • Connection type: end port or side port.
  • Available pressure type: 150, 300, 450, 600, 800, 1000, 1200 psi.
  • Length type: 1-6 core.
  • Color configuration: standard color is white, other colors are also available.
  • Accept special specifications customized.
  • Shell leakage test: water pressure test.
  • Test pressure: 1.5 times design pressure.
  • Allow operating temperature range: -7°C - 49°C.

FRP pressure vessel features:

  • Optional port type.
  • FRP winding shell design, durable.
  • Polyurethane coated protection.
  • Safe and reliable, convenient disassembly and assembly.


  • For more product details, you can go to see our FRP membrane housing web page.
  • The information and guidelines in this user's guide is only as a supplement for good industrial practice, the responsibility of correct operation and maintenance about membrane housing is still in the users.

End plate assembly drawing

A detailed picture about end plate assembly, and each part is marked with a number.

FRP membrane housing end plate assembly, and its parts as below:

  • 1 - Fixing bolt.
  • 2 - Block ring.
  • 3 - Fastened bolt.
  • 4 - Supporting plate.
  • 5 - End plate.
  • 6 - Seal ring.
  • 7 - Plate seal ring.
  • 8 - Adapter.
  • 9 - "O" type seal ring.
  • 10 - Thrust ring.

Shell components

A sealing plate with honeycomb shaped surface.
Sealing plate, bearing plate components.
A black end plate with two red square cap shaped parts.
End plate.
Three crescent shaped baffles and three bolts.
Crescent shaped baffle, bolt.
Two stainless steel blocking pieces and two bolts.
Blocking piece.
Two black saddles in different sizes, the smaller one is on the front.
Two straps and four screws, the short one is on the front.
Two black adapters in different sizes, the smaller one is behind the bigger one.
A black thrust ring of FRP membrane housing.
Thrust ring.
A stainless steel side port.
Side port.
Two stainless steel couplings.
Six white seal rings in different sizes.
Seal rings.
Two stainless steel clamps.

Installation Guide (take 8" FRP membrane housing as example)

FRP membrane housing ten steps installation:

  1. Completely fixed the bracket.
  2. The pressure vessel according to the manufacturer's recommended span (S) horizontal support and reliable fixation. (more details to see engineering drawings.)
    • Ensure that you are based on the manufacturer's recommended span (S) horizontal support and reliable fixation.
    • Ensure that the saddle and strap which used to fixed pressure vessel is provided by the manufacturer.
    • No rigidity fixation and connection to the pressure vessel.
  3. Clean all the components of the end plate and the inner surface of pressure vessel. (Prohibit use of strong acid, strong alkali solution, recommended use of water or neutral solution.)
  4. The surface of sealing ring, the sealing area of the pressure vessel inner surface should be properly coated with lubricant. (suggest to use glycerin)
  5. Put the thrust ring load into the pressure vessel, and then put the concentrated water end plate load into it.
  6. Push membrane elements into the membrane housing one by one until the adapter is connected to the permeate port of the membrane element.
    Ensure adequate assembly space, provide sufficient space for the installation of pressure vessels and membrane elements. Membrane elements are generally pushed into from the feed water port end and replaced from the concentrate water port end.
  7. Put feed water port end plate arranged in the pressure vessel and ensure the connection of the adapter and the membrane element net water outlet.
    Use a rubber hammer to knock supporting end plate until the baffle plate is inserted into the card slot.
  8. Put the three crescent shaped retaining ring into the end slot, alignment to the bolt hole, and use six angle wrench to tighten the screw.
  9. Tighten the pipe plug.
  10. Connect piping.
    • Ensure that the pressure vessel of fixed and piping connection have flexible leeway, this is in order to adapt to radial and lateral changes influence of the pressure vessel under the action of pressure or temperature.
    • Ensure that the piping and the F/C port of side port pressure vessel free docking, and maintain concentric.
    • Forbid the pressure vessel to bear the piping weight.

FRP membrane housing installation attention:

  • When installing the sealing plate, please pay attention to the protection of the sealing ring. Lubricant should be applied evenly, slope area in ring groove mouth of end plate should be applied lubricant evenly. This aids to ensure the end plate sealing ring lubrication propulsion.
  • Check the tightening strength of bearing plate fasten nut, make sure that the sealing plate is connect with the bearing plate tightly.
  • Examine all components of the end plate, prevent the installation of omissions, prevent debris omission in the membrane shell.
  • Check whether the thrust ring is in the concentrated water port, this is to prevent the damage to the filter membrane element and adapter when system operation running.
  • Check connections (coupling, clamps) to ensure that the installation is in place.
  • Upon completion of the installation check, use wash pump in low pressure and low flow start to give membrane (the membrane shell) slowly water supply. Discharge the air in membrane element and membrane shell, after emptying, and then pressure releasing, reciprocating several times to prevent water hammer phenomenon. Ensure that the sealing ring stretches freely and reset.
  • Fresh water pipe pressure shall not exceed 125 psi, pay attention to the fresh water pipe whether there is any foreign body in it.
  • Membrane housing can not be used as load-bearing carrier, cannot be loaded pressure on its upper part, prohibit the application of pressure on its direct associated accessories.
  • Consequences of not in accordance with operating procedures, our company shall not be subject to any liability or responsibility.

Disassembly instructions:

Use inner hexagon spanner to unscrew fastening screws of the three crescent shaped baffle and remove.
Screw the special tool bolt into the net water outlet inner hole, use plate rod to rotate bolt and slowly pull out end head assembly.
Collect unloading components, examine if they need to be replaced and this is help to install in next time.

Before ensuring that the pressure of the container is fully released, it is forbidden to open the container, otherwise it will cause physical harm or even endanger life!

Specific operation method:

First step: release pressure.
Stop the corresponding pressure source, close the inlet valve, open system emptying valves, completely release the pressure inside the shell.

Second step: contamination removal.

  1. Use a small wire brush to sweep away the metal oxidation products and mineral deposits that adhere to the inside of membrane housing.
  2. Use plenty of clean water to flush away the loose rust, mill scale, dirt, grease, oil, old paint and other deposits.

Third step: removing the head.

  1. Break off the connection of permeate piping at the nearest convenient joint and pay attention to the threaded connections of the plastic permeate port(s), do not put undue pressure on it.
  2. Remove the retaining ring from the groove.
    It is better to accomplished by using specialized tools that is provide by our company. It can also be finished by using a screwdriver and a pair of pliers if there is no specialized tools.
    1. With specialized tools.
      Insert the specialized tool over the tab on the retaining ring and just simply rotate the tool counterclockwise, the retaining ring can be lifted upward and pull the end of the retaining ring straight out.
    2. With a screwdriver and a pair of pliers.
      Use the tip of screwdriver to pry the tabbed end of the retaining ring out of groove, until the end of the retaining ring is clear of the groove.
      And then use the pliers to grab the tab, pull it toward the end of the shell, until the ring is at the end edge of the shell.
  3. Rotate your fingers behind the retaining ring and remove it from the groove.
  4. Examine if the head or shell is damaged by burr when the retaining ring is removed.
  5. Screw the special tool bolt into the net water outlet inner hole, use plate rod to rotate bolt and slowly pull out end head assembly.
  6. Collect unloading components, examine if they need to be replaced and this is help to install in next time.

Repeat the above operation to the other side of the membrane housing.

After removing, examine all the head parts whether they need to be replaced or refurbished.

Maintenance requirements:

Please comply with the following provisions and recommendations in order to ensure the safe operation of the membrane housing.

  • Please comply with the rated design pressure index, operate the pressure vessel in the range of allowable values, over pressure operation is strictly prohibited.
  • The normal working temperature of FRP membrane housing is generally in the range of -7°C - 49°C, strictly prohibited to operate it beyond the temperature range.
  • The shell can withstand the PH range: 3-10.
  • Back pressure shall not exceed 125 psi.
  • Conventional fluid medium are soft water, sewage and seawater. For special fluids, please contact our company in advance to avoid an accident.
  • When the system is operating or the inner of membrane shell has pressure, do not beat, disassemble or mobile shell, strictly control the influence of vibration source.

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Mecraw Filter Company
E-mail: sales@membranehousing.org

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