WIKA PGS43.160 - Handbuch (Seite 12)

12
Sealing of
the thread 
Wrench surface
Sealing area 
Installation with
spanner
Flange connection 1)
1) The screw connection of the
flange must not be opened
080
4
.03 1
/
009 GB/D/F/E
GB
WIKA Operating instructions pressure gauges Model 4 with 831 per ATEX
7. Commissioning, operation
Mechanical connection
In according with the general technical regulations for pressure gauges (i.e.
EN 837- "Selection and installation recommendations for pressure gauges").
When screwing gauges in, the force required for this must not be applied
through the case, but rather through the spanner flats (using a suitable tool)
provided for this purpose on the square shaft of standard connections.
Correct sealing of pressure gauge connections with parallel thread  shall
be means of a suitable sealing ring, sealing washer or WIKA profile seals. The
sealing of tapered threads (e.g. NPT threads) is made by providing the thread  ,
with additional sealing material like, for example, PTFE tape (EN 837-).
The torque depends on the seal used. With standard G-type pipe thread, gauge
connection by means of a union nut or a LH-RH adjusting nut is recommended
to simplify correct orientation of the gauge. When a blow-out device is fitted to a
pressure gauge it shall be resistant to blocking by debris and dirt.
With safety pattern gauges (see dial symbol k ) you need to pay attention to the
fact that the free space behind the blow-out back will be at least 15 mm.
Requirements for the installation point
If the measuring point is not adequately stable a measuring instrument support
such as a bracket or flange should be used for fastening (and possibly via a
flexible capillary line). If the pressure gauge is exposed to vibration or pulsating
pressure or both, then a liquid filled pressure gauge may provide considerably
better performance and readability. Instruments should be protected against
coarse dirt and wide fluctuations in ambient temperature.

7. Commissioning, operation