Membrane Cleaning Procedures

Spectra Service Bulletin

We do not recommend cleaning your membrane unless you are sure that it is indicated. With a Spectra System cleaning is required when higher than normal pressures are encountered and the water production has fallen. Always check the prefilters first. Every cleaning will shorten the life of the membrane.

For normal cleaning, the SC-3 Acid Cleaning Compound is used first, then the SC-2 Alkaline Cleaning Compound. If known bio-fouling is present, the SC-2 may be used first. Using hot water if possible, up to but not to exceed 120º, is highly recommended as it greatly enhances the ability of the cleaners to do their jobs.

If the history of the system is unknown or has been left "unpickled" for an extended length of time and biological growth is present, it is recommended that the system is cleaned with the SC-2, using an alternate source of unchlorinated fresh water before the system is run under pressure. A simple test can be performed to see if biological growth has occurred: Before running the system, remove the pre-filters and examine their condition. If the housings are full of discolored smelly water, the system was not properly stored. Install clean pre-filters if they were bad. Next check the membrane. Attach the brine discharge service hose and lead to a container. Open the pressure relief valve 1 turn and turn the brine discharge service valve to the "Service" position. Manually run the system for 30 seconds. Examine the brine water; if it’s discolored and smells bad, perform a SC-2 cleaning with an alternate source of unchlorinated water before running the system pressurized. If the brine is fairly clean, the system can be purged, run normally, and checked for performance. Clean the membranes only if performance is reduced.

Heating the water is preferable. One way to do this is find a camp stove and use a large SS pot to heat the solution in. The cleaning solution throughout the system will heat as it circulates in and out of the pot. An alternative is to heat the one or two gallons of initial water in the cleaning container to up to 120° F on the main stove before mixing in the cleaner and circulating it into the system. Periodically stop and reheat the solution.

Perform the cleaning procedures while the ship is in acceptable sea water for purging and testing.

Cleaning Procedures

Note: procedures are the same for the SC-3 and SC-2 cleaners

A Spectra Cleaning Compound (SC-2 or SC-3) must be mixed with fresh water at a ratio of 1 Spectra container to 3 gallons to have the proper solution. An average of two gallons of water is in a 400 system or 4 gallons in a 1000 system. This water has to be figured in the mixture. A 400 system uses one cleaner container, a 1000 system uses two containers. SC-3 and SC-2 are never mixed together. Do not use them for storage.

Warning! The pressure relief valve on the Clark pump must be open for this procedure or membrane damage may result. Maximum pressure 50 psi.

Note: Triple the run/soak times if the solution is not heated

• Attach the service hoses to the three way valves and direct them to the cleaning container. Make sure the domestic water pressure system is on then start the automatic flush system. When the flush cycle stops, move only the brine discharge to the "Service" position and restart the flush cycle. Allow one gallon (400 system) or two gallons (1000 system) of flush water to flow into the container, then stop the system with the Start/Stop button. Do not use tap water or chlorinated water! Distilled or charcoal filtered water is acceptable if using the flush water is not an option. Start heating the water.
   
• With the system flushed and unchlorinated fresh water in the container, thoroughly mix the proper amount (see above) of the chosen cleaning chemical into the mixing container. Warning! Re-check that the pressure relief valve is open or membrane damage may result. Turn all the "Service" valves to the service position. Start the main feed pump manually using the manual switch on the MPC control box. Do not use the remote control panel.
   
• Run the system unpressurized for one hour while maintaining the solution at warm if possible then turn off for one hour to let the membrane soak. Don’t forget to turn off the stove. Run the system again for 1 hour while heating the solution, then turn off for one hour. Do not let the water get above 120º F! Triple the run soak times if the water is not heated.
   
• Turn the brine discharge service valve to the "Run" position. Restart the system, the solution will now drain from the container.
   
• Place the intake service valve to the "Run" position. Run the system unpressurized on sea water for at least 30 minutes to purge the cleaning solution.
   
• After purging, close the pressure relief valve to pressurize the system. Manually divert the product water with the product service valve into the cleaning container. After 30 minutes, check the feed pressure, product flow, and quality, to determine if the membrane is functioning normally. If the cleaning solution became very discolored during the cleaning process, it is recommended to repeat the process. If the first cleaning did not affect the membrane enough, repeat the cleaning process using the other cleaner. Always manually reject the product water for 30 minutes after cleaning.
   

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