VEGA VEGAPULS 45 VBUS - Manual (Page 23)

VEGAPULS 42, 44 and 45 – VBUS 23
Mounting and installation
Guidelines for standpipe construction
Radar sensors for measurement on surge or
bypass pipes are used with G 1½ A
screwed-on antenna or flange sizes DN 50,
DN 80, DN 100 and DN 150. The radar
sensor with a DN 50 flange is only a
functional measuring system in conjunction
with a measuring tube.
On the left you see the constructional fea-
tures of a measuring pipe (surge or bypass
tube) as exemplified by a sensor with DN 50
flange.
The measuring pipe must be smooth inside
(average surface quality Rz
≤
30). Use stain-
less steel tubing (drawn or welded length-
wise) for construction of the measuring pipe.
Extend the measuring pipe to the required
length with welding neck flanges or with con-
necting sleeves. Make sure that no shoulders
or projections are created during welding.
Before welding, join pipe and flange with their
inner surfaces flush and exactly fitting.
Avoid welding through the pipe wall. The pipe
must remain smooth inside. Roughness or
welding beads on the inner surfaces must be
carefully removed and burnished, as they
cause false echoes and encourage product
adhesion.
On the following page you will see the
constructional features of a measuring pipe
as exemplified by a sensor with DN 100
flange.
If the vessel contains agitated products,
fasten the measuring pipe to the vessel bot-
tom. Provide additional fastenings for longer
measuring pipes.
ø50
> 300 mm
Tube antenna system with ball valve cutoff in measur-
ing tube
Ball valve
Vent hole
Deflector
Surge pipe with ball valve
If a ball valve is mounted in the surge pipe,
maintenance and servicing can be carried
out without opening the vessel (e.g. if it con-
tains liquid gas or toxic products).
A prerequisite for trouble-free operation is a
ball valve throat that corresponds to the pipe
diameter and provides a flush surface with
the pipe inner wall. The valve must not have
any rough edges or constrictions in its chan-
nel and should have a min. distance of 300
mm from the sensor flange.