Dualator® VI treatment systems require inspection and maintenance on a semi-annual basis. Filters with elevated iron or manganese in the raw water need more frequent maintenance. We’ve included a step-by-step maintenance guide below to ensure you are optimizing your system performance.
- Fill finished water storage tanks and/or tower.
- Backwash filters to a clean effluent.
- Shut off and lock out the raw water supply and chemical feed system to the filter.
- Pump down the filter and the detention tank to their lowest level.
- Open the backwash effluent valves and allow all cells and the detention tank to finish draining until water stops flowing into the backwash sump.
- Drain down filter cells to support gravels or to bottom sample tap in the sideshell of the filter compartment. It is not necessary to completely drain the tank.
- Close the raw water influent valves for all cells. Open and inspect filter cells.
- Check for levelness and condition of media. Measure media depth (manway down to top of media) and record.
- Wash iron accumulation off trough or inlet distributor.
- Inspect the detention tank.
- If you have any accumulation of material on the walls or floors, use a pressure washer or a high-pressure hose to clean. Most of the solids removed can be flushed out through the two-inch coupling on the bottom of the detention floor on the sidewall.
- Inspect the flow control float and assembly. It should move freely up and down. If not, it will be necessary to get replacement parts. When the float is in its highest position, the flow control valve should be approximately 90% closed. The lowest position is 100% open. This can be verified by a notch or a scribed line on the shaft of the valve to indicate the disk position.
- If you have an internal raw water supply line, verify that the draindown coupling (also known as the weep hole) next to the flow control valve is open and free of debris.
- Inspect the chemical feed lines for signs of cracking or leaking, indicating replacement is necessary.
- Verify by inspection that the vent in the detention tank is clean and unobstructed.
U.S. Water’s Performance Index series is designed to share operations and maintenance best practices with plant personnel. The more our customers know about how to maintain and protect their systems, the more they can safeguard against system failures or efficiency issues.