CNG Codes, Standards, and Compliance 5

Question 1

Which standard does NFPA 52 reference for the qualification of CNG fueling station technicians performing maintenance on dispensing equipment?

Accepted Answer

CSA NGV 4.1 and 4.2

Answer

CSA NGV 4.1 and 4.2 cover the installation and maintenance of CNG fueling station equipment, including technician qualification requirements.

Question 2

A CNG station operator wants to use a new type of flexible connector not listed in NFPA 52. Under the code, this material may be acceptable if:

Accepted Answer

It is listed and labeled by a nationally recognized testing laboratory (NRTL)

Answer

NFPA 52 requires that unlisted materials or equipment be listed and labeled by an NRTL to demonstrate compliance with relevant standards.

Question 3

Under 49 CFR Part 173, CNG cylinders transported on a vehicle for resale or transfer must bear which DOT marking?

Accepted Answer

The DOT specification marking (e.g., DOT-CFFC or DOT 3T)

Answer

CNG cylinders must be marked with their DOT specification (e.g., DOT-CFFC, 3T, or 3AA) certifying they meet federal construction standards.

Question 4

NFPA 52 requires pressure relief devices (PRDs) on CNG vehicle cylinders to be directed away from which areas?

Accepted Answer

Engine compartment, passenger compartment, and fuel lines

Answer

PRD venting must be directed away from the engine compartment, passenger areas, and fuel lines to prevent ignition of vented gas in a fire situation.

Question 5

Which organization's standards are most commonly cited alongside NFPA 52 for the design of CNG compression piping systems?

Accepted Answer

ASME B31.3 (Process Piping)

Answer

ASME B31.3 Process Piping is commonly applied to high-pressure CNG compression and station piping systems due to its rigorous requirements for cyclic service.

(CNG) Compressed Natural Gas Practice Test

(CNG) Compressed Natural Gas Practice Test

CNG Codes, Standards, and Compliance 5