Quick Start Guide
3
June 2016
1.0 Primary element location
Install the Rosemount 405 in the correct location within the piping branch to
prevent inaccurate measurement caused by flow disturbances.
(1)
(2)(3)
(4)
1
1.
Consult an Emerson
™
Process Management representative if a disturbance is not listed.
2. If using flow straighteners, refer to ISO 5167 for recommended links.
3.
Use straightening vane to reduce the required straight run length.
4. In plane means the Rosemount 405 is in the same plane as the elbow. Out of plane means the bar is
perpendicular to the plane of the upstream elbow. Refer to
Figure 1 on page 4
.
Table 1. 405C Straight Pipe Requirements
(1)
Beta
0.40
0.50
0.65
Up
st
re
am (in
let
)
side
of
pri
m
ar
y
Reducer
2
2
2
Single 90° bend or tee
2
2
2
Two or more 90° bends in the same plane
2
2
2
Two or more 90° bends in different planes
2
2
2
Up to 10° of swirl
2
2
2
Butterfly valve (75% to 100% open)
2
5
5
Downstream (outlet) side of primary
2
2
2
Table 2. 405P Straight Pipe Requirements
(1)(2)
Beta
0.40
0.50
0.65
U
p
st
re
a
m
(i
n
let
)
si
de
o
f pr
im
a
ry
Reducer
5
8
12
Single 90° bend or tee
16
22
44
Two or more 90° bends in the same plane
10
18
44
Two or more 90° bends in different planes
50
75
60
Expander
12
20
28
Ball/gate valve fully open
12
12
18
Downstream (outlet) side of primary
6
6
7
Table 3. 405 Straight Run Requirements
(1)
Without
straightening vane
With straightening vane
(3)
Annubar
™
averaging pitot tube - sensor
size 1
In
plane
(4)
Out of
plane
(4)
From
disturbance
From
straightening
vane
U
p
str
e
a
m
(i
n
let
)
side
of
p
rimar
y
Reducer
12
12
8
4
Expander
18
18
8
4
Single 90° bend or tee
8
10
8
4
Two or more 90° bends in the same plane
11
16
8
4
Two or more 90° bends in different planes
23
28
8
4
Butterfly Valve (75–100% open)
30
30
8
4
Ball/Gate Valve fully open
8
10
8
4
Downstream (outlet) side of primary
4
4
4
4
00825-0100-4810_RevHA.fm Page 3 Friday, June 17, 2016 3:15 PM
