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Pipe Volume

Gallons Cubic Ft.

Leak Test

CFM Leak=VR+VP7.48×P2-P1×60T×PATM×C

Pressure at Unload / Stop

CFM Leak
  1. Identify the complete storage capacity of the system (receivers, pipes, etc) in gallons.
  2. If calculating for leaks: Be sure all prodction equipment is "off" and isolated. Isolate all auto. drains and bleeds
    If calculating for system flow demand: Be sure all production equipment is "on" and fully operational. All auto. Drains should be "on" and fully functional to allow for the additional demand.
  3. Pump the system up to the cut-out/unload of the compressor. Record this pressure.
  4. Record the time in minutes (and cut-in press.) required for the system to bleed down to the cut-in/load pressure.
  5. Enter the recorded data into the proper cells in the formula above.
  6. Use 1.0 for 10psid or below. At wider than 10psi differentials between load and unload some allowance for rate of flow change as the pressure falls must be considered. For example: if the differential is 50psid then entering a "Correction" value of 1.25 will be relatively accurate. For 20psid a 1.12 correction factor will apply.

Pump Up Test

Compressor Volume=VR+VP×0.13368×Pmax/PATMT

Compressor Volume

Volume of piping must include additions and corrections for elbows, tees, dryer vessel volumes etc. Test is to be performed from zero pressure in receiver to maximum system pressure. All drains, service valves, leak ect. must be closed or corrected prior to test. A minimum of three tests should be performed with the average of all tests used as test result.

Compressor Energy

Savings Per Year

ModulationLoad / No LoadVSD
Modulation vs Load/No Load
Modulation vs VSD
Load/No Load vs VSD

Std. CFM vs. Abs. CFM

Vapor Pressure

Pressure PSIA

Elevation vs Atmospheric Pressure

Pressure PSIA

Abs. CFM=Std. CFM×Ps-RHs×PVsPb-RHa×PVa×TaTs×PbPa

Abs. CFM of Compressor