Constant Head Flow Controller - Emerson Rosemount FCL-01 Reference Manual

Maintenance
October 2023
2. If the sensor becomes coated with rust, dissolve the rust by soaking the sensor in
3. Rinse the sensor thoroughly with water and soak in pH 4 buffer for several hours.
4. Recalibrate the sensor in buffers before returning it to service.
9.3.3 Other maintenance
The Rosemount 3900VP-02-10 sensor supplied with the FCL-02 is disposable.
It has no replaceable parts.
9.4

Constant head flow controller

9.4.1 General constant head flow controller information
After a period of time, deposits may accumulate in the constant head overflow chamber
and in the tubing leading to the flow cell(s). Deposits increase the resistance to flow and
cause the flow to gradually decrease. Loss of flow may ultimately have an impact on the
sensor performance.
The flow controller is designed to provide about 2 gal/hr (120 ml/min) flow. Loss of flow to
about 1 gal/hr (60 ml/min) causes about a 5 percent decrease in chlorine sensor output.
Loss of flow has almost no effect on pH sensor performance other than to increase the
overall response time.
9.4.2 Clean the flow controller
The flow controller can be taken apart completely for cleaning.
Procedure
1. Use a strong flow of water to flush out the tubing.
2. To prevent leaks, apply a thin layer of silicone grease (or equivalent) to the two
9.4.3 Other maintenance
Table 9-2
in the Rosemount FCL-01.
controller assembly used in the FCL-02.
48
dilute citric acid (dissolve 0.2 oz. [5 g] of citric acid crystals in 3.4 oz. [100 ml] of
water) for no longer than thirty minutes at room temperature.
Use a pipe cleaner or small bottle brush to remove more adherent deposits.
O-rings as the base of the overflow chamber and to the O-ring sealing the central
overflow tube to the base.
and Figure 9-1 show the replacement parts for the flow controller assembly used
Table 9-3 and Figure 9-2 show replacement parts for the flow
Reference Manual
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