|
Shay Plumbing IX - Feed
Water Pipes
The photo above shows the back part of the pipe and the hose. With all the bends it sort of looks like a miniature exhaust pipe. This job whole job turned out to be much less difficult that anticipated. The bent pipe took very little effort. Starting at one rear end the pipe was heated and quenched in the area for the first bend, the bend made around a !' piece of steel rod, the area for the next bend was then heated it, etc. .
Hydrostatic Test: With the feed water plumbing in place it was possible to do a hydrostatic test of the boiler and associated plumbing. Normally one would fill the boiler via the blowdown valve. However, an adaptor to connect to the drain valve hadn't been made so both the hand and axel pumps were used. Compressed air was connected to drive the engine. The water level was checked from time-to-time however, apparently not often enough as water made it to the engine. The engine sort of choked up and stopped. The hand pump was then used to build the pressure. Once all the air was expunged, the pressure builds from zero to 100 pounds with only a few pump strokes. Again, wasn't too attentive and safety valves operated and squirted water about 10 feet across workshop. What a shock! (Later showed the system to the daughter --- also an engineer. Explained everything and then pumped it up. She really jumped when the safety valves let go and squirted the water. Should have positioned her so that she would have been sprayed.) Next, the pressure was pumped up to just less than 100 psi and the system checked for leaks. There were several leaks, mostly valves and a couple compression nuts. After everything was tightened there was one very small leak in a fitting next to the axel pump control valve. Will probably just soft solder it since most of the assembly would have to be taken apart to get at it. (This joint is not subjected to steam but will use the 550 degree solder anyway.) The safety valves wept a little but don't think it's a concern. The test cock at the bottom of the water gauge continued to leak but not as much as with air. The cock will probably have to be replaced with a regular 3/16" globe valve. The steam chamber cover leaked under air pressure but didn't leak with water. This was as predicted by Murray Curtis. The safety valves were held off and the pressure pumped up to 200 psi. Other than the leaks mentioned earlier, no problems. The valves on all the boiler ports were then closed and it was verified that the boiler verified would hold pressure. Water Gauge Test: Recall that I was advised that the top of the water gauge shouldn't be connected to the turret because the water lever would vary when steam was drawn from the turret. To test this, the water level was set half way up the gauge and the system charged to about 100 psi with compressed air and the valve in the air input pipe closed off. The 1/4" blower valve was fully opened to the atmosphere (the pipe to the blower had not yet been connected to the valve). This is probably a worse case test. The water lever in the gauge increase some --- maybe a half inch. This is probably tolerable but it's clearly a bad practice. So ...... I'll go back and move the input to a dedicated port on the top of the boiler. After all the testing some of the water was drained from the tank and compressed air was fed to the boiler so that the engine could be run to clear out any remaining water. Well, the water got cleaned out ---- it ended up all over the ceiling above the smokestack. Another lesson learned ---- the hard way. On to making the fire........
|