The Level 2 bottle sizing requires some additional information beyond what is required for a Level 1 bottle sizing. For a Level 1 bottle sizing, almost all the information required can be found on the operating condition printouts. To see a comparison between the required information for a Level 1 and Level 2 bottle sizing, see the table below.
 

Information Required	Level 1 Bottle Sizing	Level 2 Bottle Sizing
Operating speed range (for capacity control)	✓	✓
Rated compressor or driver power (whichever is less)	✓	✓
Number of stages	✓	✓
Stroke length	✓	✓
Connecting rod length		✓
Rod diameter	✓	✓
Tail rod diameter (for tandem cylinder)		✓
Cylinder phasing		✓
Cylinder clearance (% of HE or CE swept volume)		✓
Unloaded valves?	✓	✓
Cylinder bore	✓	✓
Cylinder nozzle nominal pipe size (or flow area for non-standard nozzles)	✓	✓
Number of cylinders per bottle	✓	✓
Suction temperature at cylinder flange	✓	✓
Discharge temperature at cylinder flange	✓
Suction pressure at cylinder flange	✓	✓
Dischage pressure at cylinder flange	✓	✓
Ratio of specific heats [1]	✓
Compressibility [1]	✓
Gas composition [2]		✓
Specific gravity	✓
Dimensions
Distance between cylinder throws	✓	✓
Distance from cylinder to scrubber [3]		✓
Location of line-side nozzle (head or shell?)		✓
Diameter and seam-to-seam length of scrubber [4]		✓
Distance from cylinder to skid [5]		✓
Cylinder nozzle length		✓
Gas passage diameters and lengths		✓

[1] Ratio of specific heats and compressibility can be calculated from gas composition or from specific gravity (0.56 to 1.0).
[2] Gas analysis can be calculated from specific gravity (0.56 to 1.0) but there is risk with this approach.
[3] Used to estimate choke tube length between suction bottle and scrubber.
[4] Used to estimate choke tube length and scrubber volume.
[5] Dimension used to estimate maximum overhung length of discharge bottle.