58
8.0 Appendix
Table 8-5. Maximum Potential Orifice Flow Rate versus Test Pressure (Metric)
Test Pressure (cm H
2
O)
Peak Velocity (m/s)
Flow/Unit Area* (lps/sq. cm)
2
17.9
1.79
8
35.8
3.58
12
43.9
4.39
20
56.7
5.67
25
63.3
6.33
40
80.1
8.01
60
98.1
9.81
70
106.0
10.60
90
120.2
12.02
100
126.7
12.67
120
138.8
13.88
130
144.5
14.45
165
162.7
16.27
* Through a perfectly streamlined orifice (coefficient of velocity and discharge = 1).
Table 8-6. Pressure Conversion Units
Have
Multiply By
To Get
Inches of water (inH
2
O)
0.03610
Pounds per square inch
Inches of water (inH
2
O)
0.0737
Inches of Mercury (inHg)
Inches of water (inH
2
O)
2.54
Centimeters of water (cmH
2
O)
Inches of water (inH
2
O)
0.2488
Kilo pascals per square cm (kPa)
Centimeters of water (cmH
2
O)
0.3937
Inches of water (inH
2
O)
Centimeters of water (cmH
2
O)
0.0142
Pounds per square inch (psi)
Centimeters of water (cmH
2
O)
0.0980
Kilo pascals per square cm (kPa)
Centimeters of water (cmH
2
O)
0.000980
Bar
Pounds per square inch (psi)
27.71
Inches of water (inH
2
O)
Inches of mercury (inHg)
0.4897
Pounds per square inch (psi)
Inches of mercury (inHg)
13.57
Inches of water (inH
2
O)
Kilo pascals per square cm (kPa)
4.019
Inches of water (inH
2
O)
Bar
1019.74
Centimeters of water (cmH
2
O)
Bar
14.50
Pounds per square inch (psi)
