Installation
Deltatop DP71B, DP72B, DP73B
12
Hauser
3.5
General mounting conditions
3.5.1
Upstream and downstream lengths
In order to ensure a homogeneous flow profile, it is necessary to mount the Pitot tube at a sufficient
distance to narrowings or bends in the pipe. The required upstream and downstream lengths for
different types of obstacles are summarized in the following table:
Examples (schematic)
P01-DPxxxxxx-11-xx-xx-xx-008
1: Upstream length 2: Downstream length
a: 90° bend b: Valve, open c: 2x90° bend
3.5.2
Homogeneity
The medium must be homogeneous.
Changes of the state of aggregation
(liquid, gas, steam) are
not permissible.
The measuring pipe must be
completely filled
.
Type of obstacle
Min. upstream length
Min. downstream length
90° bend
7 x D
3 x D
2x90° bend
in the same plane
9 x D
3 x D
2x90° bend
in perpendicular planes
18 x D
3 x D
Concentric reducer
8 x D
3 x D
Concentric expander
8 x D
3 x D
Ball/gate valve, fully open
24 x D
4 x D
D: Inner pipe diameter
1
2
a
b
c
