Check valve on fuel return line - NFPA 20

[Piper888]

Hello,

Can anyone explain the basis of the check valve for fuel return line to be as per engine manufacturer requirement instead of being a hard requirement in NFPA 20?

11.4.4.3.1 A check valve, as specified by the engine manufacturer, shall be permitted to be installed in the fuel rentrn line only when required by the engine manufacturer.

 

[Doug Hunter]

I would guess that the engine manufacturers contributing to NFPA 20 could not agree on the specific content, and wanted to preserve their own individual design freedom.

 

[LittleInch]

There is a dedicated NFPA forum which might know more. And do a search in that forum.