Fittings cast-iron screwed

Another version of the dewatering screw that has been used successfully in a number of installations (Figure 40) consists of an inclined screw with a box-like back end and an internal overflow weir. The drive is usually a variable-speed motor reducer. Rotary air lock fitted with a variable-speed drive is typically used as shown in Figure 37 in connection with the plain receiving tank and an inclined screw conveyor. Materials of construction can be chrome-plated cast iron or nickel-hard casing. The rotary valve is made of hard faced tips or stainless steel replaceable blades. 

To enable the contents of the tank to be isolated a screw-down gate valve should be fitted adjacent to the draw-off connection. Since stresses may be applied to valves during any tank settlement or movement of pipework, cast-iron valves should not be used for this purpose. 

The whole of the cell rests on four cast iron frames insulated from the floor by porcelain insulators. Between the insulators and the cell there are set screws by which the required tilt of the electrolyzer can be set and its position fixed. Brackets are fitted to frames to support the denuder trough. On the frames between the denuder and the electrolyzer small stands are placed which have small insulators carrying the copper or aluminium bus bars. Between the cathode and the anode bus bar is a current switch which is controlled from the floor. This is for switching the bath off the circuit during repair. 

Iron Framesi—The frames for casting the finished soap are now generally made of cast-iron plates, united by movable bolts and screws—the ends and sides of which fit into an iron base,... 

Screwed or flanged joints should be kept to a minimum, and cast iron or malleable iron fittings and valves should not be used nonar-mored porcelain valves must not be used, regardless of the pressure with either liquid or gaseous phosgene. Only outside yoke or rising... 

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