15
4 Mounting
VEGADIF 85 • Profibus PA
53569-EN-230814
4.2 Instructions for oxygen applications
Warning:
As an oxidising agent, oxygen can cause or intensify fires. Oils,
grease, some plastics and dirt can burn explosively on contact with
oxygen. There is a risk of serious personal injury or damage to prop
-
erty.
Therefore, to avoid this, take the following precautions, for example:
•
All components of the system - measuring instruments - must
be cleaned in accordance with the requirements of recognized
regulations or standards
•
Depending on the seal material, certain temperatures and pres
-
sures must not be exceeded in oxygen applications, see chapter "
Technical data
"
•
Devices for oxygen applications may only be unpacked from the
PE foil just before assembly.
•
Check whether the marking "O2" is visible on the process fitting
after removing the protection for the process fitting
•
Avoid any ingress of oil, grease and dirt
4.3 Connection to the process
DP flow elements are installations in pipelines which generate a
flow-dependent pressure drop. The flow rate is measured via this dif
-
ferential pressure. Typical DP flow elements are Venturi tubes, orifice
plates or impact pressure probes.
Instructions for mounting the DP flow elements are stated in the ap
-
propriate standards as well as in the documentation from the respec
-
tive manufacturer.
Effective pressure lines are pipelines with a small diameter. They are
used to connect the differential pressure transmitter to the pressure
tapping point or the DP flow element.
Principles
Effective pressure lines for gases must always remain completely dry
and no condensate must collect. Effective pressure lines for liquids
must always be completely filled and must not contain any gas bub
-
bles. Therefore, suitable venting systems must be provided for liquids
and suitable drainage systems for gases.
Wiring
Effective pressure lines must always run with a sufficient, strictly mo
-
notonous slope/gradient of at least 2 %, but better up to 10 %.
Recommendations for wiring of effective pressure lines are stated in
the corresponding national and international standards.
Connection
Effective pressure lines are connected to the device via standard cut
-
ting ring screw connections with suitable thread.
DP flow element
Effective pressure lines