Cylinder Inspection and Regulations Flashcards
7 cards from real CNG practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Cylinder Inspection and Regulations flashcards as text
A technician finds surface rust on a Type 1 steel CNG cylinder during inspection. What is the correct initial action?
Answer: Clean the affected area and perform a close visual inspection to assess rust depth and extent before deciding
Surface rust must be cleaned and closely inspected to determine if corrosion has caused pitting beyond allowable wall-thickness limits before any service decision is made.
A CNG cylinder was exposed to a vehicle fire but appears undamaged on the outside. What is the required action?
Answer: Permanently remove the cylinder from service regardless of any visible external damage
Any CNG cylinder exposed to fire must be permanently removed from service because heat can critically weaken composite materials and alter metal properties without leaving visible external signs.
During inspection of a fiber-wrapped composite CNG cylinder (Type 2, 3, or 4), what type of damage is most likely to require rejection?
Answer: Delamination, cuts, or abrasions that expose or damage the structural fiber reinforcement layers
Delamination or cuts penetrating the structural fiber layers compromise the composite reinforcement that bears the cylinder's pressure load, requiring rejection.
A CNG cylinder's manufacturer date stamp reads '06/06.' What does this mean for its service life?
Answer: The cylinder was manufactured in June 2006 and typically reaches its end-of-life in June 2026 under a 20-year limit
A date stamp of 06/06 means the cylinder was manufactured in June 2006; applying the standard 20-year service life places the end-of-life date in June 2026.
During a CNG vehicle inspection, the technician finds the cylinder's required identification label is missing. What should be done?
Answer: Remove the cylinder from service until proper identification and service records can be verified
Without the required label, the cylinder's service pressure rating and service life expiration cannot be confirmed, making it non-compliant and unsafe for continued service.
In the context of CNG cylinder regulations, what does the term 'requalification' mean?
Answer: Periodic retesting that re-verifies a cylinder's continued safe service within its original overall service life
Requalification involves periodic inspection or hydrostatic retesting that re-certifies a cylinder type for continued use—but it cannot extend the cylinder past its original service life limit.
A vehicle owner wants to swap a CNG cylinder from one vehicle to a different vehicle of the same make and model. What is the correct response?
Answer: Permitted only if the cylinder meets all safety and pressure requirements for the receiving vehicle's system and valid service documentation transfers with it
CNG cylinder transfers require verifying that the cylinder's pressure rating, mounting compatibility, remaining service life, and full inspection history are all valid and documented for the receiving vehicle.