CWS Hardness, Scale & Corrosion Control Flashcards
6 cards from real CWS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CWS Hardness, Scale & Corrosion Control flashcards as text
The Ryznar Stability Index (RSI) is used alongside the LSI to assess water's tendency to:
Answer: Form scale or corrode
The RSI is an empirical index that uses saturation pH to predict whether water will form scale (RSI 7) pipe materials.
Black staining on fixtures and laundry is most often associated with which contaminant?
Answer: Manganese
Manganese oxidizes to form black manganese dioxide deposits, causing characteristic black or dark brown staining on fixtures, laundry, and dishes.
To neutralize acidic (low pH) well water and prevent corrosion, a water specialist would most likely recommend:
Answer: A calcite neutralizer filter
A calcite neutralizer filter dissolves calcium carbonate into acidic water, raising the pH and reducing the water's corrosive potential.
Which of the following is a direct indicator used to measure water's corrosive potential toward metal plumbing?
Answer: Copper pipe test coupon analysis
Copper coupon tests measure actual metal loss from a pipe sample immersed in the water supply, providing a direct measurement of corrosion rate.
A water with high CO2 (dissolved carbon dioxide) is likely to have:
Answer: Low pH and be corrosive
Dissolved CO2 forms carbonic acid in water, lowering the pH and making the water more corrosive to metal pipes and fixtures.
For a home with very hard water (18 gpg), which system provides the most effective long-term scale prevention for the entire house?
Answer: Whole-house ion exchange water softener at the point of entry
A whole-house ion exchange softener at the POE removes hardness minerals from all water entering the home, protecting all plumbing and appliances from scale.