Plug Valve

We think that it would be acceptable to use gate valves.....

Most often the use of gate valves is not considered a good option on gas due to the time it takes to close the unit if you needed to in a hurry. There are also some local codes that require the use of specific valves on this type of piping. I personally would only use approved rated gas line service valves on any such install. Whether it were plug or ball style valve.

Check the 'shut off' classification of the valves involved - typically gas valves have to be a tighter shutoff than gate valve suppliers offer.

A gate valve is not at all a good shutoff valve.

Shut-off valve applications routinely consider viscosity when selecting a device. This along with the generally slow manual closure of a gate valve, as mentioned, make me consider them a poor choice too.

I am familiar with using them as manual shutoff valves - the motorized automatic valves were always of a different type.