Compressed Air Temperature to use in Pipe Friction Loss Calculations
Compressed Air Temperature to use in Pipe Friction Loss Calculations
(OP)
I am trying to wrap my head around what temperature to use for friction loss calculations for a 150 psig compressed air system.
The compressors are sized to produce slightly above what the customer has stated they want for a continuous flow (~1400 scfm). I have a receiver and oversized pipe loop to provide a bit of storage and a flow control valve to manage the compressors - so they are not short cycling.
So I am assuming there will be no time to dissipate heat of compression.
I am assuming ambient conditions of 14.7 psia and 70 F at the intake of the compressor. I am assuming pressure increases to 150 psig within the system, but what is the temperature of the air. I understand the relationship PV/T (in) = PV/T (out) where P and V are changing, but how do I calculate T?
I am wanting this information to determine the weight density of air to use in my friction loss calculations. According to TP 410, air at 150 psi/70 F has a density of 0.840 lb/cf. Air at 150 psi/100 F has a density of 0.795 lb/cf.
This difference can effect pipe sizing.
Am I overanalyzing this?
The compressors are sized to produce slightly above what the customer has stated they want for a continuous flow (~1400 scfm). I have a receiver and oversized pipe loop to provide a bit of storage and a flow control valve to manage the compressors - so they are not short cycling.
So I am assuming there will be no time to dissipate heat of compression.
I am assuming ambient conditions of 14.7 psia and 70 F at the intake of the compressor. I am assuming pressure increases to 150 psig within the system, but what is the temperature of the air. I understand the relationship PV/T (in) = PV/T (out) where P and V are changing, but how do I calculate T?
I am wanting this information to determine the weight density of air to use in my friction loss calculations. According to TP 410, air at 150 psi/70 F has a density of 0.840 lb/cf. Air at 150 psi/100 F has a density of 0.795 lb/cf.
This difference can effect pipe sizing.
Am I overanalyzing this?





RE: Compressed Air Temperature to use in Pipe Friction Loss Calculations
Katmar Software - AioFlo Pipe Hydraulics
http://katmarsoftware.com
"An undefined problem has an infinite number of solutions"
RE: Compressed Air Temperature to use in Pipe Friction Loss Calculations
RE: Compressed Air Temperature to use in Pipe Friction Loss Calculations
http://repository.tamu.edu/bitstream/handle/1969.1...
Looks like 8-Inch pipe for that capacity.
RE: Compressed Air Temperature to use in Pipe Friction Loss Calculations
Do you really want to use a control valve to even pressure, or a tank rated for 150 psig? Those aren't that expensive, and will give you a place to drain condensate and mount a filter and dehumidifier.
1400 cfm is a substantial flow rate, what length of pipe run are you expecting in what environmental temperatures?
RE: Compressed Air Temperature to use in Pipe Friction Loss Calculations
The flow rate is large (largest I have ever designed for), but it is what the client said was to be the "constant" flow requirement.
I have about 750 feet from the compressors to the most remote use and the environment will be a "hangar" so it will not be too hot.
I contacted the air compressor supplier (which I should have done earlier). they design their compressors to produce air 15 F higher than ambient - so I am going to go with 100 F.
Thanks for the help and links to tips.
RE: Compressed Air Temperature to use in Pipe Friction Loss Calculations
RE: Compressed Air Temperature to use in Pipe Friction Loss Calculations
RE: Compressed Air Temperature to use in Pipe Friction Loss Calculations