ANSI Standards CSA ANSI NGV 4.7-2020 pdf free download – Automatically pressure operated valves for natural gas dispensing systems CSA ANSI NGV 4.7-2020 pdf free download - Automatically pressure operated valves for natural gas dispensing systems. 2 Reference publications This Standard refers to the following publications, and where such reference is made, it shall be to... 02-19 Download Now