Emerson Rosemount 1195 - Page 168

10-5
Figure 10-3. Pipe Length
Requirements for Installation.
U D
U D
A) REDUCER
B) SINGLE 90° BEND
U
DU D
U D
U D
E) EXPANDER
F) GLOBE/GATE VALVE
FULLY OPEN
D) TWO OR MORE 90° BENDS IN
DIFFERENT PLANES
The following chart gives the upstream (U) and downstream (D) lengths, in conformance with ISO 5167, required for the above installations. The lengths are
given in terms of pipe diameters. For example, for a 1 in. line size with a beta ratio ( b ) of 0.4 using installation type B above, the straight length of upstream
piping required is 14 ⫻1 = 14 in., and downstream 6 ⫻1 = 6 in.
Orifice
Bore
⫼
Pipe
Bore
b
On Upstream (U inlet side of the primary device)
On downstream (D
outlet side)
A
Reducer
(2 d to d over a
length of 1.5 d to 3
d)
B
Single 90°
bend or tee
(flow from one
branch only)
C
Two or more
90° bends in the
same plane
D
Two or more
90° bends in
different planes
E
Expander
(0.5 d to d
over a length
of d to 2 d)
F
Globe valve
fully open
G
Gate valve
fully open
All fittings included
in this table
<0.20
0.25
0.30
0.35
5
5
5
5
10
10
10
12
14
14
16
16
34
34
34
36
16
16
16
16
18
18
18
18
12
12
12
12
4
4
5
5
0.40
0.45
0.50
0.55
5
5
6
8
14
14
14
16
18
18
20
22
36
38
40
44
16
17
18
20
20
20
22
24
12
12
12
14
6
6
6
6
0.60
0.65
0.70
0.75
9
11
14
22
18
22
28
36
26
32
36
42
48
54
62
70
22
25
30
38
26
28
32
36
14
16
20
24
7
7
7
8
C) TWO OR MORE 90° BENDS IN
THE SAME PLANES
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