1. False. An insulating connector made of nonconducting material should be used where dissimilar metals will be joined to reduce the possibility of galvanic corrosion. This is not necessary when joining pipes of the same materials. Remember also, since using water lines as safety grounds for the electric wiring system is common practice, these insulating connectors should not be used in main water lines unless a grounding strap is used to maintain the existing electrical grounding.
2. False. Use of a pipe cutter leaves a burr on the inside diameter of pipe which can be removed with a pipe reamer. This procedure is a necessity to eliminate excessive pressure drop and/or water cavitation in the piping system.
3. True. A bypass valve is necessary to avoid a house having no water supply when the treatment system is out of service.
4. True. A critical requirement for a mechanical filter is sufficient water to backwash the filter at the required rate. Without sufficient water for backwash, the bed will tend to plug and the filter efficiency will suffer.
5. True. A UV lamp should not be operated outside the conditioner. Irritation to eyes and skin may result.
6. a. A pH range of 6.2 to 8.5 is acceptable for manganese greensand. However, this filter is more efficient if the pH range is between 7.2 to 7.8.
7. c and d. The typical chemical feed/oxidizing filter system consists of a chemical feed pump with a solution tank, a retention tank, a mineral tank with media and backwashing valve.
8. a, b and d. In addition to pre and post filters and membrane, the undersink RO system includes a storage tank (also mounted under the sink) and a separate faucet for dispensing the product water. Including a booster pump is often a good idea for low-pressure household RO systems, but this appurtenance is optional and less typical.
9. c. Residential line pressure RO systems normally operate in a range of 20 to 100 psi. If the system operates consistently in the low end of the range, however, water quality and product rate will both decline. A more realistic low range is 30 psi, and the higher the pressure (up to the membrane’s maximum pressure rating), the better the product water quality will be.
10. a and c. The drain clamp must never be installed on the drain trap. Wastewater stagnates in the trap and could lead to back pressure and plugging in the RO drain line.
