Guidelines for standpipe construction, Mounting and installation – VEGA VEGAPULS 45 4 … 20 mA; HART compact sensor User Manual

Page 21

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VEGAPULS 42, 44 and 45 – 4 … 20 mA

21

0 %

~45˚

ш 100,8

0,0…0,4

1,5…2

3,6

0,0…0,4

150…500

5…10

3,6

ш 95

2

100 %

VEGAPULS 44

Flange DN
100

Connecting
sleeve

Welding neck
flanges

Welding of the smooth
welding neck flanges

Welding of the connect-
ing sleeves

Meas. pipe fastening

Vessel
bottom

Deflector

Deburr the
holes

Welding of the welding
neck flange

Mounting and installation

Guidelines for standpipe construction

Radar sensors for measurement on surge or
bypass tubes are used with G 1½ A screwon
antenna or in the flange sizes DN 50, DN 80,
DN 100 and DN 150. The radar sensors with
a DN 50 flange only form a functioning meas-
uring 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 radar sensor with a
DN 50 flange.

The measuring pipe must be smooth inside
(average roughness Rz

≤ 30). Use stainless

steel tubing (drawn or welded lengthwise) for
construction of the measuring pipe. Extend
the measuring pipe to the required length
with weld-on flanges or with connecting
sleeves. Make sure that no shoulders or
projections are created during welding. Be-
fore 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.

In the following illustration you see the con-
structional features of a measuring pipe as
exemplified by a radar sensor with a 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.

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