Pressure relief valve?

Saw this relief valve servicing the gas line between the HWT and furnace. Can’t say I’ve seen this before. Am I right in assuming its a relief valve? Comments please.

That is a watts 210 I believe. It cuts off the gas to the water heater.

That looks like a valve not a relief device.

The below and to the left is the same except for the missing handle.


installed watts 210

Yeah. It’s not even going into the WH is it? I can’t tell.