Voyager IV
Nitrox System
Nuvair www.nuvair.com
Page
31
17.4 LP Feed Air Filtration
Special attention needs to be given to the arrangement of the four LP Feed Air Filtration
Elements and Bowls. Properly reinstall each Element and Bowl to the correct Housing.
Improper sequence can cause damage to downstream components.
The use of Grade D or better feed air is critical to prevent the passing of any residual oil vapor into
the Membrane System. Four stages of Hankison LP filtration are used to produce Grade D air:
1) Coalescing Filter
2) Coalescing & Water/Oil Vapor Removal to 1 Particulate micron
3) Coalescing & Water/Oil Vapor Removal to 0.01 Particulate micron
4) Final Stage - Oil Vapor Removal to 0.003 PPM
LP Filtration Inspection
Open each Filter and inspect as follows:
1) Inspect Bowl for the presence of moisture. A high level of moisture build-up in the HF11-24 or
HF7-24 Filter indicates improper operation of auto-drain floats. Evidence of any moisture in the
HF1=24 Filter indicates air is not cooling properly and moisture is not properly being removed.
Check HF1 canister weekly for moisture. Moisture indicates possible refrigerated dryer problem.
Excess moisture will prevent the final filter from operating properly and can lead to damage of the
membrane.
HF1-24
HF5-24
HF7-24
HF11-24
Oil
Coalescing Particle
Vapor
&Water/Oil
&
Coalescing
Removal
Vapor
Moisture
Removal
Removal
Replacement Element Part Number
E1-24
E5-24
E7-24
E11-24
Air Flow
HF5-24Filters
with Auto-
Drain Float &
Liquid Level/
Service
Indicators
Housing
HF1-24
Filter with
Manual
Drain –
Should not
Contain
Moisture
HF7-24 Filter
with Auto-
Drain Float &
Liquid Level
Indicator
Bowl
HF11-24
Filter with
Auto-Drain
Float & Liquid
Level
Indicator