The factors that influence SCC attack are temperature, chlorides, tensile stresses and oxygen level. For these types of applications chlorides and oxygen levels are fixed by the water chemistry, but chlorides can concentrate in splash zones or at the water /air line by evaporation. The wetting of the external insulation of the tanks can also cause this to become a hazard. The fixing of the working temperatures of the Stainless Steel Tanks should be done by the controls of the tank system but the problem of hot spots may arise if the concentration of chlorine occurs as described.
Screw Conveyor or auger conveyor is a mechanism that uses a rotating helical screw blade, called a 'fighting', usually within a tube, to move liquid or granular materials. They find use in a lot of industries handling bulk. The use of screw conveyors in the modern industries is done with a slight inclination or horizontally to make it easy to transport the semi solid material such as food wastes and wood chips. The screw conveyor used in the times ancient to pump water for irrigation is called the Archimedean screw.
The use of a spiral blade coiled around a shaft and contained in a trough or tube which is driven at one end and held at the other is done, or a 'shiftless spiral', driven at one end and free at the other. The rotation rate of the shaft has a direct relation to the rate of transfer of volume. In industrial control applications the device is often used as a variable rate feeder by varying the rotation rate of the shaft to deliver a measured rate or quantity of material into a process.
Switchgear, as referred to in industries using electric power systems consists of a combination of fuses, circuit breakers and electrical disconnects used for the isolation of the equipments using high voltage or current. The use of switchgear is made to disconnect equipments from high power lines to conduct repairs or clear faults. The direct link of this type of equipment to the reliability of electrical hardware makes them important.