PowerFlow Paper Solutions

Valve Flushing

On This Page

Purpose

Valve flushing exercises all dilution valves through their full range of motion. This maintenance operation:

  • Prevents sticking: Removes fiber buildup that can cause valves to stick
  • Verifies operation: Confirms all valves respond correctly
  • Extends life: Regular exercise prevents seal degradation
  • Identifies problems: Non-responding valves are detected early
Process Impact

Flushing temporarily moves valves to extreme positions, which will affect the paper profile. Perform flushing during sheet breaks or grade changes to minimize process impact.

Flushing Modes

Sequential Flush

Flushes one zone at a time, from first to last zone. Minimizes process impact but takes longer.

Duration: ~5-10 minutes Impact: Low

Group Flush

Flushes zones in groups (e.g., every 4th zone together). Faster than sequential with moderate impact.

Duration: ~2-4 minutes Impact: Medium

All-at-Once

Flushes all zones simultaneously. Fastest completion but highest process impact.

Duration: ~30 seconds Impact: High

Flushing Procedure

  1. Open Flushing Dialog

    Navigate to Operations > Valve Flushing

  2. Select Flushing Mode

    Choose the appropriate mode based on current conditions:

    • Sequential: During normal operation (if unavoidable)
    • Group: During grade changes
    • All-at-Once: During sheet breaks only

  3. Configure Parameters

    Flushing Settings

    Flush Position 100% Full open position
    Hold Time 5 sec Time at flush position
    Return Position Previous Where to return after flush
    Zone Delay 500 ms Delay between zones (sequential)

  4. Select Zones

    Choose which zones to flush:

    • All Zones: Complete system flush
    • Zone Range: Specific range (e.g., zones 1-24)
    • Single Zone: Test individual valves

  5. Execute Flush

    Click Start Flushing to begin the sequence

  6. Monitor Progress

    The progress bar shows flushing status. You can:

    • Watch valve positions in Zone Display
    • Click Stop to abort if needed
    • Wait for "Flushing Complete" message

  7. Verify Results

    After flushing completes:

    • Check all zones returned to proper positions
    • Verify no alarms triggered
    • Note any zones that failed to respond

Recommended Schedule

Condition Frequency Mode
Normal operation Once per shift Sequential or Group
After grade change Each change Group (during transition)
After extended downtime Before startup All-at-Once
Sticky valve suspected Immediate Single zone (affected)
Weekly maintenance Weekly All-at-Once (during break)
Timing Tip

Schedule valve flushing to coincide with sheet breaks. This provides the opportunity to use the faster "All-at-Once" mode without affecting paper quality.

Troubleshooting Non-Responding Valves

If a valve doesn't respond during flushing:

  1. Verify electrical connection to valve
  2. Check PLC communication status
  3. Attempt manual movement in the Zone Control panel
  4. Inspect physical valve for mechanical issues
  5. Contact maintenance if problem persists