Spectra Watermakers Ventura 150T MPC, Installation And Operating Manual

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Introduction to Spectra Chemicals continued...
Complete microbial preservative protection requires a 25% solution of propylene glycol, so
care must be taken that the solution remaining in the watermaker during long term storage is
at least 25%, even if freeze protection is not required. For these reasons Spectra recommends
that all pickling be carried out with a 60% or greater concentration.
Propylene glycol can be difficult to flush from a membrane, especially after extended storage
periods. This results in high salinity water (high PPM) and residual flavor in the product water.
We recommend flushing the system WITH THE PRESSURE RELIEF VALVE OPEN for 4-6 hours
after storage with propylene glycol—the longer the better. If, after extended flushing, you still
experience low product water quality, cleaning with SC-2 usually removes all traces of propyl-
ene glycol and returns the salinity to the level it was before storage with propylene glycol. See
the Cleaning Procedure on page 48.
See Winterizing with Propylene Glycol on page 47.
Cleaners
Cleaning can be detrimental to the membrane and shorten its life. Avoid unnecessary clean-
ing, and avoid cleaning as a diagnostic tool.
SC-2 is an alkaline cleaner used to remove light oil, grime and biological growth. It is most
effective if heated to 120 deg. F (49 deg. C), which is difficult on a boat. In most cases the wa-
ter quality will increase in PPM (salinity) after an SC-2 cleaning. After a few hours it should re-
cover to near the level it produced before the cleaning
.
SC-3 is an acid cleaner used to remove mineral and scale deposits. In most cases this is used
first and if there is no improvement, go on to the SC-2. SC-3 will in most cases lower the prod-
uct PPM and overall pressures. Scaling is a slow process that may take several months or
years. SC-3 is less harmful to the membrane and will almost always improve the performance
of an older membrane.
For cleaning with either SC-2 or SC-3, see the Cleaning Procedure on page 48.