
Bleed Down Test Calculator





CFM LEAK = (VR + VP)* (P2  P1
(abs))*(60) / (T)*(PATM)*C









VR =

Volume of Receiver in Gallons





VP =

Volume of Piping in Gallons





P2 =

Maximum Pressure at Unload / Stop





P1 =

Minimum Pressure at Load / Start





T =

Time of Test from No Load to Load (Stop to Start) (Sec)




PATM =

Atmospehric Pressure (Site Corrected)





C

Correction factor (See
note 6 below)









VR






VP






Total CF=






P2






P1






ATMP






T






C






System Leakage
(CFM)










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

2a. 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 cutout/unload of the
compressor. Record this pressure.

4. Record the time in minutes
(and cutin press.) required for the system to bleed down to the cutin/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.

Contact Accurate Air Engineering, Inc for options to correct
your compressed air systems inefficiencies

Cerritos:
562.484.6370


San Diego:
619.401.8270

Bakersfield:
661.323.7597


Lodi:
209.334.4340
