< Fittings 2 >
<< regulator >>
The William's regulator is a simple screw type. To release maximum steam with a minimum rotation of the handle, it has course thread and obtuse angle tip in the valve. The valve body is hold in the boiler, with a brass pipe fixed onto the regulator bush in the backhead. Note a small hole in the valve body to eliminate pressure difference between inside and outside of the brass tube.
The valve and the spindle is connected rigidly with a small pin across them. The valve tip has 120 degree angle.
Both end of the brass tube were squared in the lathe with 'fixed steady'.
Design of the regulator handle was modified for easy operation. The base plate was finished in a rotary table. It has two press-fitted cocks.
The square hole was cut with a half-round cutter which had been made for the smokebox door handle.
A short phosphor bronze pipe was solver-soldered onto the outlet tube. Because the pipe is projected into the wet header and sealed with an O-ring.
<< check valves >>
The hand wheel is just a 'dummy'. Also the phosphor bronze spindle is just a limit for the ball valve and it doesn't rotate. It holds the hand wheel and was lightly jammed with a hammer. The hand wheel can rotate freely.
A short union pipe is silver soldered to the valve body through the gland nut. Note a dummy plug hanging up the gland nut during the soldering operation.
<< blowdown valves >>
They are at the both sides of the boiler foundation ring. Martin Evans' design employs ball valve in a holder, instead of simple needle valve. The ball have to rotate freely in the holder, otherwise it is no sense using 'ball'.
The valve seat was finished with a D-bit made from carbon steel bar. The tip of the D-bit was end-milled in correct angle. Then the tool was hardened, tempered and ground with oil stone.
The blowdown valve have to be made as short as possible, because the side rod sweeps just upon it. The valve end was cut hexagonal and is operated by a special tool which was made from Allen screw and round wood.
<< oil mist trap >>
This is an idea of an expert. A brass cup with a thin plate and a tube is set at the bottom of the blast pipe. Exhaust flow from both cylinder is screened by the plate. Then oil mist is trapped, dropped into the cup and let out through the tube by blast pressure. You can get oil-free smoke from chimney.