Dwyer instruments, inc – Dwyer PE User Manual
Page 2
The above curved graph shows pressure loss generated by the Series
PE Orifice Plate Flow Meter. For example, a 0.7 Beta Ratio (d/D) would
show a loss of 51%. This is also shown on the linear graph area ratio
(d/D)
2
=.38 with a loss of 62%.
As a quick check reference, you can use the formula:
Head loss =1-Beta Ratio
2
eg: 1-0.7
2
or 1-0.49 = 51% of the d.p.
Source: ASME Research Report on Fluid Meters
Magnehelic
®
and Capsuhelic
®
gages from Dwyer read pressure drop
across the orifice plates.
For compatible gases a Dwyer Magnehelic
®
gage may be used to read
the differential pressure.
AIR AND GAS FLOW - CONCENTRIC BORE
SCFM BASE CONDITIONS 14.7 psia & 60°F
Conversion formula used to solve for flow rate based on plotting
changes in inlet pressure, temperature and/or differential pressure.
This formula is designed for use as a “quick check” reference only as
the results may differ from calculation values due to rounding,
combining of variables, and making certain assumptions in an effort to
keep the formula as abbreviated as possible.
Equation source Flow
Measurement Engineering Handbook by Richard Miller.
Input new differential pressure (h/w) as well as new pressures
and/or temperatures using the formula below:
Where:
5.9816 = physical constant
d = bore in inches
D = pipe inside diameter (inches)
K = flow coefficient
Y = expansion factor
h/w = differential pressure (inches w/c)
P
L
= line pressure (psia)
T
L
= line temperature (°F)
Tb = base temperature (°F)
ß = beta ratio (d/D)
SG = specific gravity at line conditions (air=1.00)
SH = specific heat ratio cp/cv (air=1.4)
Rn = Reynolds number at max flow in pipe
K= C x ((1)/( 1-ß
4
))
Y= 1- (.41+.35ß
4
) ((h/w x .0361)/ (PL x 1.4))
C= 0.5959 + 0.0312Я
2.1
– 0.1840Я
8
+ 91.71Я
2.5
Rn
-0.75
If Reynolds number (R
n
) is not known, “C” can be estimated as
0.6015. For convenience other factors can be combined to form
constants as the equation is developed.
Note: Differential pressure values should be less than 50% of the inlet absolute pressure.
MAINTENANCE
After final installation of the Series PE Orifice Plate Flow Meter, no
routine maintenance is required. A periodic check of system calibration
is suggested. With the exception of gasket replacement, these
devices are not field repairable and should be returned if repair is
needed (field repair should not be attempted and may void warranty).
Be sure to include a brief description of the problem plus any relevant
application notes. Contact customer service to receive a return goods
authorization number before shipping.
Series PE Orifice Plate Flow Meter
Air Capacity Structure
Model
#
PE-A-1
PE-A-2
PE-A-3
PE-B-1
PE-B-2
PE-B-3
PE-C-1
PE-C-2
PE-C-3
PE-D-1
PE-D-2
PE-D-3
PE-E-1
PE-E-2
PE-E-3
PE-F-1
PE-F-2
PE-F-3
PE-G-1
PE-G-2
PE-G-3
PE-H-1
PE-H-2
PE-H-3
PE-J-1
PE-J-2
PE-J-3
PE-K-1
PE-K-2
PE-K-3
PE-L-1
PE-L-2
PE-L-3
PE-M-1
PE-M-2
PE-M-3
PE-N-1
PE-N-2
PE-N-3
PE-O-1
PE-O-2
PE-O-3
PE-P-1
PE-P-2
PE-P-3
PE-Q-1
PE-Q-2
PE-Q-3
PE-R-1
PE-R-2
PE-R-3
PE-S-1
PE-S-2
PE-S-3
PE-T-1
PE-T-2
PE-T-3
Line
Size
1/2"
1/2"
1/2"
3/4"
3/4"
3/4"
1"
1"
1"
1.25"
1.25"
1.25"
1.5"
1.5"
1.5"
2"
2"
2"
2.5"
2.5"
2.5"
3"
3"
3"
4"
4"
4"
5"
5"
5"
6"
6"
6"
8"
8"
8"
10"
10"
10"
12"
12"
12"
14"
14"
14"
16"
16"
16"
18"
18"
18"
20"
20"
20"
24"
24"
24"
Bore
0.200"
0.310"
0.430"
0.250"
0.400"
0.580"
0.300"
0.520"
0.720"
0.400"
0.700"
1.00"
0.500"
0.800"
1.100"
0.600"
1.000"
1.450"
0.750"
1.250"
1.750"
0.920"
1.500"
2.150"
1.200"
2.000"
2.800"
1.500"
2.500"
3.500"
1.800"
3.000"
4.200"
2.400"
4.000"
5.600"
3.000"
5.000"
7.000"
3.600"
5.000"
8.400"
4.000"
6.600"
9.300"
4.500"
7.600"
10.700"
5.200"
8.600"
12.000"
5.780"
9.600"
13.500"
7.000"
11.700"
16.300"
Beta
0.32
0.5
0.69
0.3
0.49
0.7
0.29
0.49
0.69
0.29
0.51
0.72
0.31
0.5
0.68
0.29
0.48
0.7
0.3
0.5
0.7
0.3
0.49
0.7
0.3
0.5
0.7
0.3
0.5
0.69
0.3
0.49
0.69
0.3
0.5
0.7
0.3
0.5
0.7
0.3
0.5
0.7
0.3
0.5
0.7
0.3
0.5
0.7
0.3
0.5
0.7
0.3
0.5
0.7
0.3
0.5
0.7
Inch d.p.
W/C
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
20
100
200
• Material PVC- Gaskets Buna "N"
• Based on 70°F, 14.7 psia (Base Conditions)
• Beta Value Based on Std Sch pipe I.D.
• 1.25˝ overall thickness
• Orifice plate thickness is 0.125˝
at 14.7 PSIA
(0 PSIG)
2.35
12.21
32.77
3.65
20.21
59.92
5.24
34.2
91.28
9.31
62.09
180
14.57
80.82
212.18
20.92
125.74
372.09
32.71
197.54
543.99
49.17
282.9
816.7
83.58
503.76
1,380.03
130.48
786.23
2,152.83
187.86
1,331.63
3,097.20
333.87
2,014.95
5,532.00
521.58
3,145.50
8,626.42
750.9
4,530
12,430.00
927.14
6,477.67
15,251.50
1,172.63
7,264.58
20,179.85
1,565.79
9,302.08
25,299.92
1,935.37
11,588.20
32,115.34
2,838.14
17,229.62
46,810.53
at 20 psig
3.63
19.58
56.15
5.66
32.44
102.91
8.11
54.92
156.51
14.41
99.75
309.97
22.55
129.68
363.93
32.38
202.03
639.87
50.64
317.58
936.56
76.13
454.77
1,404.95
129.44
810.06
2,373.02
202.11
1,264.42
3,701.57
291
1,820.05
5,325.20
517.25
3,241.45
9,525.43
808
5,060.38
14,846.80
1,163.44
7,288.16
21,397.00
1,436.59
8,812.87
28,262.66
1,817.05
11,688.26
34,749.32
2,426.34
14,966.93
43,535.32
2,999.11
18,645.74
55,303.34
4,398.25
27,726.33
80,610.19
at 100 psig
6.61
36.37
107.47
10.3
60.26
197.2
14.8
102.09
300
26.3
185.5
595.2
41.16
241.5
697.39
59.13
375.8
1,227.63
92.48
590.91
1,798.86
139.06
846.21
2,696.28
236.48
1,507.64
4,553.68
369.29
2,353.51
7,103.22
531.75
3,387.93
10,219.28
945.28
6,034.85
18,290.00
1,476.77
9,421.74
28,506.17
2,126.47
13,570.33
41,089.02
2,625.81
16,409.42
50,427.78
3,321.32
21,764.08
66,737.64
4,435.12
27,869.85
83,587.01
5,482.22
34,720.84
106,215.88
8,038.99
51,633.81
154,823.78
Weight
(lbs)
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
2.00
3.00
3.00
3.00
3.00
3.00
3.00
4.00
4.00
4.00
5.00
5.00
5.00
6.00
6.00
6.00
7.00
7.00
7.00
9.00
9.00
9.00
10.00
10.00
10.00
12.00
12.00
12.00
14.00
14.00
14.00
16.00
16.00
16.00
SCFM =
5.9816 x (d
2
) x (K) x (Y) x h/w x (2.703 x P
L
x SG)/(460 + T
L
)
√
√
2.703 x 14.7 x SG
460 + T
b
DWYER INSTRUMENTS, INC.
Phone: 219/879-8000
www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A.
Fax: 219/872-9057
e-mail: [email protected]
©Copyright 2009 Dwyer Instruments, Inc.
Printed in U.S.A. 7/09
FR# 443397-00 Rev.2
Note: Differential pressure values should be less than 50% of the inlet absolute pressure.
AIR CAPACITY - Flow in SCFM
√
F-PE:F-PE bulletin 8/17/09 1:31 PM Page 2