Hach Accu4 User Manual page 16

Figure 9 Closed-loop piping arrangement
1 Outlet (½–in. NPT female)
2 To open atmosphere (to vent for
calibration)
3 Isolation ball valve (½–in. IPS)
4 Process output
5 Isolation ball valve (½–in. IPS)
16 English
6 Process output
7 3-way valve (½–in. IPS)
8 Inlet (½–in. NPT female)
9 3-way valve (½–in. IPS)
Figure 10 Sample bypass line configuration
1 Outlet (½–in. NPT female)
2 Isolation ball valve (½–in. IPS)
3 To open drain
Connect the sample stream
Install the sample line into a larger process pipe to minimize interference
from air bubbles or pipeline bottom sediment. A sample line that goes
into the center of a process pipe is best.
Figure 11 shows examples of good and bad methods of sample line
installation into a process pipe.
Keep the sample line as short as possible to decrease analysis delay.
Sediment can collect in long sample lines.
4 Isolation ball valve (½–in. IPS)
5 Process input
6 Inlet (½–in. NPT female)