Vaisala HMT330 User Manual
Page 195
Appendix A _________________________________ Probe Installation Kits and Installation Examples
VAISALA _______________________________________________________________________ 193
NOTE
The probe can be installed in the process through the ball valve
assembly provided that the process pressure is less than 10 bars. This
way, the process does not have to be shut down when installing or
removing the probe. However, if the process is shut down before
removing the probe, the process pressure can be max. 20 bars.
NOTE
When measuring temperature dependent quantities make sure that the
temperature at the measurement point is equal to that of the process,
otherwise the moisture reading may be incorrect.
Follow the steps below to install the HMT338 probe through a ball valve
assembly. After the installation, the probe should be sitting in the process
chamber or pipeline as shown in Figure 102 on page 192.
1.
Shut down the process if the process pressure is more than 10 bars.
If the pressure is lower there is no need to shut down the process.
2.
Close the ball valve.
3.
Seal the threads on the fitting body; refer to Figure 29 on page 47.
4.
Attach the fitting body to the ball valve and tighten it.
5.
Slide the clasp nut of the probe toward the filter, as far as it will go.
6.
Insert the probe to the fitting body, and manually tighten the clasp
nut to the fitting body.
7.
Open the ball valve.
8.
Push the probe through the ball valve assembly into the process. If
the pressure is high, use the pressing handle that is provided with
the probe. If you push the probe hard without using the handle, you
may damage the cable.
Note that the probe must be pushed so deep that the filter is
completely inside the process flow.
9.
Mark the fitting screw and the clasp nut.
10. Tighten the clasp nut with a fork wrench a further 50 ... 60º
(ca. 1/6 turn). If you have a suitable torque wrench, tighten the nut
to max 45 ± 5 Nm (33 ± 4 ft-lbs). Refer to Figure 30 on
page 48.
NOTE
Take care not to tighten the clasp nut more than 60° to avoid difficulties
when opening it.
If you wish to remove the probe from the process, note that you have to
pull the probe out far enough. You cannot close the valve if the groove
on the probe body is not visible.