1.0 ppm (max)


0.10 ppm (max)

Moisture (water vapor measured by ppm or measured by dew point)

7 ppm (max) >-83°F


Qdor free

Reference: Military Specification MIL-Q-27210F

m Collaborate with other government agencies and commercial industry on gas purity standards and sampling procedures related to diver's breathing gases.

4-4.1 Maintenance Requirements. Taking periodic air samples is a required mainte nance action and shall be performed in accordance with the PMS card(s) applicable to the compressor or system producing diver's breathing air. Each diver

Table 4-4. Diver's Compressed Helium Breathing Purity Requirements.



Helium (percent by volume)


Moisture (water vapor)

7 ppm (max)

Dew Point (not greater than)


Hydrocarbons (as Methane)

1 ppm (max)


3 ppm (max)

Nitrogen + Argon

5 ppm (max)


23 ppm (max)


1 ppm (max)

Reference: Military Specification MIL-PRF-27407B

breathing-air source in service must be sampled approximately every 6 months (within the interval between 4 and 8 months following the last accomplishment), when contamination is suspected and after system overhaul.

Do not use a compressor that is suspected of producing contaminated air or that has failed an air sample analysis until the cause of the problem has been corrected and a satisfactory air sample analysis has been obtained validating the production of acceptable air.

Diving systems that do not have a high-pressure (HP) air compressor within the scope of certification shall only be charged with air produced by HP air compressors listed on the ANU list and must have all applicable PMS completed up to date, including air sample requirements. Examples of these types of systems include MK 3 LWDS, Roper Cart, and various diving boats. HP banks on these systems need not be sampled unless contamination is suspected.

Air drawn from submarine HP air storage banks for use as diver's breathing air shall be sampled in accordance with the PMS maintenance requirement card applicable to the system, i.e., dry deck shelter system, submarine escape trunk, scuba charging station. See paragraph 4-4.2 for additional information on system line-up for sampling compressors where a sampling connection cannot be made immediately downstream from the last air filtration device.

Table 4-1 shows the minimum purity requirements for diving air produced by ANU-approved and certified diving air compressors. Air sampling services may be procured locally from government or commercial air analysis facilities, or may be acquired by utilizing analysis services coordinated via Coastal Systems Station (CSS), Panama City, Florida.

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