Heater line part identification help

I'm not good on A/C cars, but we are looking at a heater control valve. It should be on the inlet hose side and allows heated water to flow through the core. You are testing it correctly, it should open and close. Just don't know if that is an original one or not. With valve open, you can disconnect the return hose to see if the water is flowing. If it is flowing you should get some heat if the water is hot.