Ask X3What does 49 CFR 173.172 (Aircraft hydraulic power unit fuel tank) require?
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According to 49 CFR 173.172, aircraft hydraulic power unit fuel tanks containing M86 fuel (a mixture of anhydrous hydrazine and monomethyl hydrazine) designed for installation as complete units in aircraft are excepted from standard specification packaging requirements if they meet one of two specific sets of conditions:
Condition (a):
* Vessel construction: Must be an aluminum pressure vessel made from tubing with welded heads.
* Primary containment: A welded aluminum bladder with a maximum internal volume of 46 L (12 gallons).
* Pressure ratings: The outer vessel must have a minimum design gauge pressure of 1,275 kPa (185 psig) and a minimum burst gauge pressure of 2,755 kPa (400 psig).
* Leak testing: Each vessel must be leak-checked during manufacture and before shipment and found to be leakproof.
* Packaging: The complete inner unit must be securely packed in non-combustible cushioning material (such as vermiculite) inside a strong, tightly closed outer metal packaging that adequately protects all fittings.
* Quantity limit: Maximum fuel quantity per primary containment and package is 42 L (11 gallons).
Condition (b):
* Vessel construction: Must be an aluminum pressure vessel.
* Primary containment: A welded, hermetically sealed fuel compartment containing an elastomeric bladder with a maximum internal volume of 46 L (12 gallons).
* Pressure rating: The pressure vessel must have a minimum design gauge pressure of 5,170 kPa (750 psig).
* Leak testing: Each vessel must be leak-checked during manufacture and before shipment and found to be leakproof.
* Packaging: Must be securely packed in non-combustible cushioning material (such as vermiculite) inside a strong, tightly closed outer metal packaging that adequately protects all fittings.
* Quantity limit: Maximum fuel quantity per primary containment and package is 42 L (11 gallons).