VEGA VEGAPULS 66 (≥ 2.0.0 - ≥ 4.0.0) Profibus PA - Manual (Page 20)

20
4 Mounting
VEGAPULS 66 • Profibus PA
36521-EN-121011
•
The tube diameter must be at least DN 40 or 1½" with antenna
size 40 mm (1½")
•
For the parameter adjustment, select "Application standpipe" and
enter the tube diameter to compensate errors due to running time
shift
•
A false signal suppression with integrated sensor is recommended
but not mandatory
•
The measurement through a ball valve with complete run is pos-
sible
Constructional requirements on the surge pipe:
•
Material metal, smoother inner tube
•
Preferably pultruded or straight beaded stainless steel tube
•
Welded joint should be straight and lie in one axis with the holes
•
Flanges are welded to the tube according to the orientation of the
polarisation level
•
In case of a extension with a welding neck flange or pipe collar
as well as when a ball valve is used, the inner surfaces should be
aligned and accurately joined together
•
Gap size with junctions ≤ 0.1 mm
•
Do not weld through the pipe wall. The surge pipe must remain
smooth inside. Roughness and beads on the inside caused by
unintentional penetration should be removed since they cause
strong false echoes and encourage buildup
•
Surge pipes must extend all the way down to the requested min.
level, as measurement is only possible within the tube
•
Diameter of holes ≤ 5 mm, any number OK, on one side or com-
pletely through
•
The antenna diameter of the sensor should correspond to the
inner diameter of the tube
•
Diameter should be constant over the complete length
An alternative to measurement in a surge pipe is measurement in a
bypass tube outside of the vessel.
Measurement in the
bypass