Vaisala DMT340 - Manual (Page 39)

Chapter 3 ________________________________________________________________ Installation
VAISALA ________________________________________________________________________ 37
DMT344 For High-pressure Applications
The DMT344 probe is for the dewpoint measurements in pressurized
rooms and industrial processes. The probe is provided with a nut, a fitting
screw and a sealing washer. Keep the fitting screw and the nut in place
on the body of the probe during handling to prevent damage to the highly
polished surface of the probe. Follow the instructions below to achieve a
leak-tight assembly:
1. Remove the fitting screw from the nut and the probe.
2. Fasten the fitting screw to the chamber wall with a sealing washer.
Tighten the fitting screw into the threaded sleeve with a torque
spanner. The tightening torque is 150 ± 10 Nm (110 ± 7 ft-lbs).
3. Insert the body of the probe into the fitting screw and install the nut
manually to the fitting screw so that the connection feels tight.
4. Mark both the fitting screw and the nut hex.
0506-029
Figure 21 DMT344 Probe
The numbers refer to Figure 21 above:
1 = Tightening cone
2 = Nut
3 = Fitting screw, M22x1.5 or NPT 1/2"
4 = Sealing washer
5 = Probe; Ø12 mm
5. Tighten the nut a further 30º (1/12) turn or if you have a torque
spanner tighten it with a torque of 80 ± 10 Nm (60 ± 7 ft-lbs).
0503-034
Figure 22 Tightening the Nut