Natural Gas Valve Train Flow

 Posts:2
 Joined:Thu Oct 25, 2012 2:06 pm
I am working on designing a natural gas valve train. The knowns are the inlet pressure, outlet pressure, temperature, density, and volumetric flow rate. Is it possible to size the piping with this information? I have used the Pipe Diameter calculator, but I get hung up in that I don't have a velocity. Is it possible to do the calculation without a velocity? If so, what is the equation? If not, how can I calculate the velocity with the given information? Any help is greatly appreciated. Thank you.
Re: Natural Gas Valve Train Flow
Please provide data to help you.
Pipe flow calculations  since 2000

 Posts:2
 Joined:Thu Oct 25, 2012 2:06 pm
Re: Natural Gas Valve Train Flow
We have an input pressure of 60 psig. The pressure required at the burner (output pressure) is 22.75 psig. We have a required flow of 10503 SCFM. The length of the pipe is 16 ft. The operating temperature is 30 C. The density is 0.78 kg/m^3.
Re: Natural Gas Valve Train Flow
I would suggest you to use 20 m/s maximum velocity
For inlet condition I get following:
Pipe diameter calculator
1. volumetric flow rate (q):
q : 2066.3394 ft3/min  this is at 60 psig
2. mass flow rate (w):
w : 437.06238 lb/min
3. diameter (D):
D : 249.16525 mm
4. velocity (v):
v : 20 m/s
5. cross section area (A):
A : 48760.137 mm2
6. pressure of gas (p):
p : 74.695432 psi  absolute pressure
7. density (ρ):
ρ : 3.3881354 kg/m3
8. temperature (T):
T : 20 C
9. gas constant (R):
R : 518.8 J/kgK
For outlet:
1. volumetric flow rate (q):
q : 4349.694 ft3/min
2. mass flow rate (w):
w : 437.06238 lb/min
3. diameter (D):
D : 361.5064 mm
4. velocity (v):
v : 20 m/s
5. cross section area (A):
A : 102641.26 mm2
6. pressure of gas (p):
p : 36.69543 psi
7. density (ρ):
ρ : 1.6095471 kg/m3
8. temperature (T):
T : 30 C
9. gas constant (R):
R : 518.8 J/kgK
Control valve is another problem to calculate if you have one?
For inlet condition I get following:
Pipe diameter calculator
1. volumetric flow rate (q):
q : 2066.3394 ft3/min  this is at 60 psig
2. mass flow rate (w):
w : 437.06238 lb/min
3. diameter (D):
D : 249.16525 mm
4. velocity (v):
v : 20 m/s
5. cross section area (A):
A : 48760.137 mm2
6. pressure of gas (p):
p : 74.695432 psi  absolute pressure
7. density (ρ):
ρ : 3.3881354 kg/m3
8. temperature (T):
T : 20 C
9. gas constant (R):
R : 518.8 J/kgK
For outlet:
1. volumetric flow rate (q):
q : 4349.694 ft3/min
2. mass flow rate (w):
w : 437.06238 lb/min
3. diameter (D):
D : 361.5064 mm
4. velocity (v):
v : 20 m/s
5. cross section area (A):
A : 102641.26 mm2
6. pressure of gas (p):
p : 36.69543 psi
7. density (ρ):
ρ : 1.6095471 kg/m3
8. temperature (T):
T : 30 C
9. gas constant (R):
R : 518.8 J/kgK
Control valve is another problem to calculate if you have one?
Pipe flow calculations  since 2000