VALVES
2
VAL-325
For further information www.norgren.com
Air/Gas Flow Calculations
1. Find back pressure on horizontal axis.
2. Draw vertical line to intersect with operating pressure curve; at this point
draw horizontal line to vertical axis. This is the flow for a valve with a Cv
factor of 1 in SCFM (standard cubic feet per minute).
3. Use the Cv factor from the catalog listing, and multiply this Cv by the
flow from step two above. This is the air flow through the specific valve
you have selected.
4. If the media is not air multiply the flow by a correction factor. Examples
of correction factors are:
Helium 2.69
Hydrogen 3.85
Methane 1.33
Oxygen .95
Propane .80
Other Fluids = 1
S.G.
0
20
40
60
80
100
120
140
160
20
20
40
60
80
100
120
140
160
180
200
220
240
40 60 80 100
BACK PRESSURE (PSIG)
120 140 160 180 200
FLOW
IN SCFM
@ 70°F
EXAMPLE
Media: Oxygen
Back Pressure: 100
Operating Pressure: 120
Cv factor - KIP Series 6 valve, 3/64 orifice,
2-Way Normally Closed: .050
Back Pressure on Chart = 100
Operating Pressure Curve = 120
Air flow x Cv factor = 50 x .050 = 2.50
Valve Flow with air
x Correction factor
= 2.50x.95 = 2.375 SCFM
This is the flow of oxygen through a KIP PIN 651111 valve under these
conditions.
KIP Calculations
