Well Red, not to nit-pick too much here but "that's my story and I'm sticking to it". I was assuming the valve would be tested in the closed position. If you connect a faucet to it, crack the tap open, and wait a little while, the pressure in the valve will be the same as the water pressure to your house. And, on a '47 I thought the "thermostatic feature" was pull the knob out if you want it warmer and push it in if you want it cooler.
