VEGA VEGADIF 34 … 51 - Manual (Page 42)

42 VEGADIF 34 … 51
20094-EN-030731
5 Typical installation
connections
5.1 Valves
For VEGADIF 34 and 35 the use of three or
fivefold valve blocks which can be directly
flanged to the transmitter is recommended.
These offer the following advantages:
- Mounting and dismounting of the transmitter
are possible without interrupting the proc-
ess.
- With the fivefold valve block there are two
valves for vent drain (for gasing liquids) or
for condensate drain (for condensating
gases).
Typical valve connections with threefold
valve block
(standard connection)
For impulse lines, a block valve should be
provided on each pressure tapping point. The
threefold valve block includes two inlet valves
and one equalisation valve.
The two inlet valves are used to block the
measuring cell from the impulse lines.
The equalisation valve is used for zero-point
adjustment of the transmitter especially in flow
and level measurement.
Installation connections
Typical valve connections for a fivefold
valve block
(connection also in liquids with impurities)
For each impulse line, a block valve should be
provided at the pressure tapping point. The
fivefold valve block includes two inlet valves
and one equalisation valve as well as two
additional blow down valves. This connection
is also suitable for liquids with impurities. The
two inlet valves are used for blocking the
measuring cell from the impulse lines.
The equalisation valve is used for zero point
adjustment of the transmitter especially in flow
and level measurement.
Two additional blow down vales are used to
drain off buildup in the impulse lines. The pipe
between the T-branch and the blow down
valve is used as catch pan.
Observe the following procedure for cleaning:
1 Close inlet valves
2 Open blow down valves
By doing this, the impulse lines are cleaned
from the pressure tapping point to the blow
down valves. A pipeline from the blow down
valves to an appropriate outlet is recom-
mended.
from the pressure
tapping points
Block valves
Threefold valve block
Inlet valves
Equalisation valve
to the transmitter
to the pressure tapping
points
Block valves
Fivefold valve block
Blow down valves
Equalization valve
to the
trans-
mitter
Inlet valves
to outlet