This is one of the most recommended and used equations for this type of flow, being able to estimate with high precision flow and pressure drop values if pipe roughness is known with correctness. It has been used for comparison among the different flow equations as a reference basis because it is fundamental to the definition of the corresponding application ranges and errors.
Similar to the Colebrook Equation, the AGA Equation uses a slightly modified transmission factor in order to obtain a value for the pressure drop using the General Flow Equation. The transmission value for the AGA equation is the following:
This equation is also known as the Von Karman equation for rough pipe flow.
๐น โ Transmission Factor
๐ โ Pipe Roughness
๐ท โ Internal Diameter (in)
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๐ โ Flow Rate (FT3/day)
๐ถ๐ย โ 38.774
๐๐ย โTemperature Base (ยฐR)
๐๐ย โ Pressure Base (psi)
๐๐ย โ Gas Flowing Temperature (ยฐR)
๐ท โ Internal Diameter (in)
๐ โ Pipe Roughness
๐1ย โ Upstream Pressure (psi)
๐2ย โ Downstream Pressure (psi)
๐บ โ Gas Specific Gravity
๐ โ Compressibility Factor
Leย โ Pipe Segment Length including Expansion (mi)
๐๐ย โ Gas Flowing Temperature (ยฐR)
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๐ โ Elevation adjustment parameter
CS โ 0.0375
๐ โ Compressibility Factor
๐๐ โ Gas Flowing Temperature (ยฐR)
โ๐ป๐บ โ Change in Elevation (ft)
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๐ฟ๐ โ Pipe Segment Length including Expansion (mi)
๐ โ Elevation adjustment parameter
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๐ โ Velocity (ft/sec)
๐โ โ Volumetric flow rate (scf/hr)
๐ท โ Internal Diameter (in)
๐๐๐ฃ๐ โ Average Pipeline Pressure (psia)
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