Spectra Watermakers VENTURA 150, Installation And Operation Manual

Page: 48 / 74

48
With any product water quality issue, you must ensure accurate calibration if you are using a
salinity meter. For general quality evaluation, your taste is always good enough.
Using membranes for water desalination through reverse osmosis is not an exact science and
two identical systems can have different product quality. World health standards deem
water of up to 1000 PPM of total dissolved solids acceptable for drinking. We consider any
thing below 750 PPM acceptable but not ideal, and anything below 500 PPM excellent.
Factors that could affect water quality are addressed below.
LOW SYSTEM FLOW OR PRESSURE will equate to lower product quality (higher PPM).
Ventura systems, which have a higher feed to output pressure ratio (See nominal
pressures under Flow Test, page 28), as well as a higher feed flow/membrane area
ratio, will produce water in the 150
- 200 PPM range.
DAMAGE TO THE MEMBRANE by chlorine contamination. Flushing the system with
chlorinated water will irreparably damage the membrane. Charcoal filters are used to
absorb any chlorine which might be present in flush water. They must be of proper
specification to be suitable. See page 49. There is no test for chlorine damage except
the process of elimination of other causes.
DIRTY OR SCALED membranes. A dirty (foreign material), scaled (mineral deposits), or
contaminated (bacterial growth) membrane can result in poor water quality and
abnormal operating pressures. If operating pressures are above normal, then cleaning
is indicated. If the system pressures are within operating normal range, cleaning may
have little result. Avoid cleaning as a diagnostic tool. Low water quality after storage
with propylene glycol can usually be remedied by extended flushing or an SC
- 2
cleaning. (See pages 44 - 45 and 48.)
MECHANICAL LEAKAGE within the membrane pressure vessel. This is an unlikely but
possible cause of poor water quality. A pinched or damaged O - ring within the
pressure vessel, a scratch on the product tube on the membrane, a scratch within
one of the end caps, or a seal fouled by contamination could allow sea water into the
product water.
If system flow (product plus brine) is 1.5 GPM or above, the membrane is clean, the product
flows are consistent with the system flow and the water quality is still not acceptable, then
replacement of the membrane is indicated.
Poor Product Water Quality