NSS Series
Nuvair
Page 25
www.Nuvair.com
14.0 Appendix
14.1 Supply and Breathing Air Specifications
All supply and breathing air must meet the following requirements of CGA G-7.1-1997. Periodic air quality
testing to assure compliance is recommended. All breathing air for diving produced by a downstream fill
containment station must be purified to meet Grade E quality, and periodic air quality testing to assure
compliance is mandatory.
Item
Grade D
Grade E
Oxygen
19.5-23.5%
20-22%
Carbon Dioxide (maximum) 1000 PPM
1000 PPM
Carbon Monoxide
(maximum)
10 PPM
10 PPM
Hydrocarbons (maximum)
Not specified
25 PPM
Water Vapor (maximum)
Not specified
Not specified
Dew Point (maximum)¹
Not specified
Not specified
Oil & Particles (maximum)²
5 mg/m³
5 mg/m³
Odor
None
None
Notes: ¹ Dew point of supply air must be >10
o
F (6
o
C) colder than coldest ambient air expected.
² Supply air delivered to the membrane system must contain <0.003 PPM oil vapor.
14.2 Filter Element Life Factors
Breathing air filter element life is typically rated by manufacturer based on an air temperature of 80ºF at the
filter inlet. Under normal operation this temperature is +12ºF (+5ºC) warmer than the ambient air, resulting in
an equivalent ambient temperature rating at +68ºF (+20ºC).
To determine element life at a different ambient temperature, multiply the rated life by the life factor listed
below:
Filter
Temperature
Ambient
Temperature
Filter Element
Life Factor
53ºF (12ºC)
41ºF (5ºC)
2.6
×
Life
62ºF (17ºC)
50ºF (10ºC)
1.8
×
Life
71ºF (23ºC)
59ºF (16ºC)
1.35
×
Life
80ºF (27ºC)
68ºF (20ºC)
1
×
Life
89ºF (32ºC)
77ºF (25ºC)
0.8
×
Life
96ºF (36ºC)
84ºF (29ºC)
0.55
×
Life
105ºF (41ºC)
93ºF (34ºC)
0.45
×
Life
114ºF (46ºC)
102ºF (39ºC)
0.35
×
Life
