27
Replacing the Immersion Tube
The immersion tube must be removed or replaced:
• for general maintenance
• for cleaning the immersion tube, e.g., after the sensor is broken
• for replacing the sensor gasket (O-ring)
• in the event of a technical fault of the drive unit
The wetted part of the immersion tube is made of PTFE. The upper part of the immersion tube
(T)
is provided with a stainless steel endpiece with bayonet contour
(U)
. This endpiece serves for
connecting the immersion tube to the drive unit of the retractable fitting.
The endpiece is aligned with the three windows
(Q)
in the immersion tube
and non-rotatably con-
nected to the tube body (see the centerline in the figure below). This fixed alignment is imperative
to ensure an easy connection and an optimal rinsing result for the retractable fitting.
If the endpiece is not properly aligned or can be twisted, the tube is defective.
In this case, you must replace the immersion tube.
High process pressures and high process temperatures can cause the immersion tube to shrink
(known creep tendency of PTFE).
Before installing the immersion tube, always check its total length as shown above. If the total
length X is more than 2 mm shorter than specified (see figure and table), you must replace the
immersion tube.
U
Q
T
Immersion Tube
SensoGate WA 132
x
- 2 mm
Short
Long
x = 149 mm
x = 204 mm
