Best replacement option for corroding hot water valve

I am hoping to find the best replacement option for a corroding hot water valve on the supply line for the hot water heater tank. I suspect the reason for the corrosion are dissimilar metals reacting to each other (valve and pipe).

The copper line is connected to an old-type plastic material pipe that was discontinued since 1995 (forgot the name) because it became brittle with time. Anyway to replace the valve without soldering? I do not want to melt the plastic PVC pipe.

Thank you.

 

if you don't want to solder there is a(compression ball valve) you would need a
(compression coupling) also.....no shark bites they can leak

 

The valve looks fine. Tightening the nut under the handle (packing nut) often fixes the weeping under the handle.

 

Thank you for the replies. So it looks like the yellow/white powder coming from the valve-stem is water scale and not metal corrosion? So the water is leaking out very slowly and it evaporates before it would get the area wet underneath the valve?

If that's the case, I will try to tighten the packing nut. Clean the whole thing and monitor for further scale accumulation. If it reappears then I will replace the valve either with a compression setup or soldering it.

I know that soldering is the better option. But on a scale of 1 to 100, with soldering being 100 (the best) option, what would compression valve/fittings rate as far as probability of a leak in the future?

The water line with this valve must be the cold water supply because it has a blue circle around the location it enters the tank, while the other one has a red circle. What solder should I use? I know silver-flux is for high pressure lines and requires a lot of heat. I hope I can use a simple butane torch with a lower temperature solder.

Thank you again!