Pressure Relief Valve Replacement

[Sigma957]

Hello,

My how water tank is 2 years old and the pressure relief valve is leaking (not rusted and thru pvc pipe).

I tried cycling the valve to no effect but did get some sediment from the pipe.
Also tried tapping the valve lightly with hammer while valve open. Did not work to stop leak either.

So my question is does the replacement valve need silicone plumbers tape on the new valve before installing?
OR should valve just be inserted with nothing on the valve?

I know about draining tank a bit, shutting off gas and water.

Thanks
Sigma