I am looking to install a gas water heater and wondering is the blue PVC is able to handle this? I know there is a Green (I think) pipe that is put together with a specialized heat gun.

I'd really not get involved with that if there is no need.

You will be best with CPVC I have no idea of the colour here in Thailand.

It operates up to 200 degrees Fahrenheit whereas PVC is 140.

The blue pipe is not suitable, use green pipe, google upvc -----cpvc.

The cpvc I used was white and bought from a Homeworks shop. When you buy the different fittings, remember to buy the fitting removal tool!

The blue pipe is not suitable, use green pipe, google upvc -----cpvc.

And it is the green pipe with the red stripe, not the one with the white stripe. You can get both push fit and weld fit connections for it. It is called PP-R