Yokogawa Pneumatic Retractables RF20H - Manual (Page 6)

IM 12B06K05-E-E
6
Fig. 1: Retractable holder
Variations
Retractable holders are attached to tanks or piping
by an applicable process connection. In order to
comply with the various process properties the
RF20H (Extract 810 and 820) retractable holder is
fabricated of stainless steel, Alloy C-22 or plastic.
You can further choose between different process
and cleaning ports, sealing materials, and sensors.
Drive
Compressed air is supplied via the pneumatic
connections on the drive unit. The drive unit inserts
the insertion rod in the process medium up to the
maximal insertion depth. For safety reasons this is
only possible with a sensor installed.
Measuring
When reaching the final position of the “measuring”
position, the control receives a pneumatic position
feedback signal. In this position the sensor head is
immersed in the drive unit and cannot be removed.
The sensor measures the chemical or physical
properties of the process liquid.
Service
Cleaning, rinsing and calibration of the sensor
is possible while the process is running. For
this purpose the holder must be moved to the
“service” position. Another pneumatic position
signal feedback is given when the final position is
reached. In the “service” position the insertion rod
seals the cleaning chamber against the process
to prevent leakage of process liquid. The required
liquid is introduced into the cleaning chamber via
the cleaning port “IN” and subsequently drained via
the cleaning port “OUT”.
2. Product description
2.1 RF20H (Extract 810 and 820) automatic retractable holder
1. Pneumatic connections 1-4
2. Top housing cramp
3. Drive unit
4. Lower housing cramp
5. Process connection
6. Sensor
7. Insertion rod with protection cage
8. Cleaning port “IN”
9. Cleaning port “OUT”
10. Cleaning chamber
Components