Reference, Pressure loss – Yokogawa digitalYEWFLO (DY) User Manual
Page 128
<13. GENERAL SPECIFICATIONS>
13-18
IM 01F06A00-01EN
Reference
Table 13.11 Inner Diameter and Nominal value
Model Code
Inner
Diameter
mm
Nominal
K-Factor
Pulse/L
Nominal Pulse
Rate
Hz / m/s Hz / m
3
/h
DY015
DY025
/R1
DY040
/R2
14.6
376
62.7
104
DY025
DY040
/R1
DY050
/R2
25.7
68.6
35.5
19.1
DY040
DY050
/R1
DY080
/R2
39.7
18.7
23.1
5.19
DY050
DY080
/R1
DY100
/R2
51.1
8.95
18.3
2.49
DY080
DY100
/R1
DY150
/R2
71.0
3.33
13.2
0.925
DY100
DY150
/R1
DY200
/R2
93.8
1.43
9.88
0.397
DY150
DY200
/R1
—
138.8
0.441
6.67
0.123
DY200
—
—
185.6
0.185
5.00
0.0514
DY250
—
—
230.8
0.0966
4.04
0.0268
DY300
—
—
276.2
0.0563
3.37
0.0156
DY400
—
—
354.2
0.0265
2.61
0.00736
Pressure Loss
Calculation of pressure loss for standard type
obtained from the following equations.
P=108Ч10
−5
Ч
f
×
2
······ (1)
or
P=135×
f
×
Q
f
2
D
4
········· (2)
where,
P: Pressure loss (kPa )
f
: Density at operating condition (kg/m
3
)
: Flow velocity (m/s)
Q
f
: Actual
fl ow rate (m
3
/h)
D: Inner diameter of digitalYEWFLO (mm)
(Example)
DY050, hot water: 80°C, fl owrate: 30 m
3
/h
1. Since the density of water at 80°C is 972 kg/
m
3
, substitute this value in equation (2):
P = 135 Ч 972 Ч 30
2
/ 51.1
4
= 17.3 kPa
2. Obtain the pressure loss using equation (1).
The fl ow velocity when the fl ow rate is 30 m
3
/h
is given by:
=
354×Q
f
/D
2
=
354×30
51.1
2
= 4.07m/s
Therefore, substitute this value in equation (1):
P = 108 Ч 10
-5
Ч 972 Ч 4.07
2
= 17.3 kPa
Calculation of pressure loss for reduced bore
type (Option code: /R1)
obtained from the following equations.
P = 124 Ч 10
-5
Ч
f
×
2
··········· (3)
or
P = 155 ×
ρ
f
× Q
f
2
/ D
4
············ (4)
(Example)
DY040/R1, hot water: 50 °C, fl owrate: 10 m
3
/h
1. Since the density of water at 50 °C is 992 kg/
m
3
, substitute this value in equation (4):
P = 155 Ч 992 Ч 10
2
/ 25.7
4
= 35.3 kPa
2. Obtain by using equation (3). The fl ow velocity
when the fl ow rate is 10 m
3
/h is given by:
= 354 × Q
f
× /D
2
= 354 Ч 10 Ч 25.7
2
=
5.4m/s
Therefore, substitute this value in equation (3):
P = 124 Ч 10
-5
Ч 992 Ч 5.4
2
= 35.3 kPa
Calculation of pressure loss for reduced bore
type (Option code: /R2)
obtained from the following equations.
P = 138 Ч 10
-5
Ч
f
×
2
··········· (5)
or
P = 173 ×
f
×
Q
f
2
D
4
················ (6)
(Example)
DY050-/R2, hot water: 50 °C, fl owrate: 15 m
3
/h
1. Since the density of water at 50 °C is 992 kg/
m
3
, substitute this value in equation (6):
P = 173 Ч 992 Ч 15
2
/ 25.7
4
= 88.5 kPa
2. Obtain by using equation (5). The fl ow velocity
when the fl ow rate is 15m
3
/h is given by:
=
354×Q
f
/D
2
=
354×15
25.7
2
= 8.0m/s
Therefore, substitute this value in equation (5):
P = 138 Ч 10
-5
Ч 992 Ч 8.0
2
= 88.5 kPa