18
11041781.04 01/2020 EN/DE
Pressure gauge with reed contact model 851-A, for Ex areas
EN
When screwing the instruments in, the force required for sealing
must not be applied through the case, but only through the
spanner flats provided for this purpose, and using a suitable tool.
For parallel threads, use flat gaskets, lens-type sealing rings or
WIKA profile sealings at the sealing face . With tapered threads
(e.g. NPT threads), sealing is made in the threads , using a
suitable sealing material (EN 837-2).
The torque depends on the sealing used. In order to orientate the
measuring instrument so that it can be read as well as possible, a
connection with LH-RH union or union nut should be used. When
a blow-out device is fitted to an instrument, it must be protected
against being blocked by debris and dirt.
Installation
■
Nominal position per EN 837-3 / 9.6.6 figure 7: 90° ( ⊥ )
■
Process connection lower mount
Installation with open-ended
spanner
Sealing in the
thread
Spanner flats
Sealing face
5. Commissioning, operation