Primary Supply Line

The biggest impact on the supply of parts on time was clearly the way the incoming unserviceable turbines were treated. Previously, these units were fed into the process to balance the workload of the whole operation. This meant that turbines could wait several days in the fully assembled state before being disassembled. Although this workload buffer was effective in managing capacity, it caused a major delay in the supply chain dynamics. 

The approach adopted may seem obvious to establish a disassemble cell that seized the unit immediately when it arrived on site (or even in some cases earlier) and got all the components affected by the customer requirement to the point of disposition. In this way, the usability of the primary source of parts was established at the earliest moment, and the work for repair or replacement could be planned and managed inside a larger portion of the turnaround time. 

The reassembly of the turbines was organized in a series of pull cells. This was most effective from a physical work organization process. However, initially these cells called for the required parts from a central stores. While maintaining good stores accuracy, this placed an immense load on the stores operation and little direct visibility by those who actually rebuilt the units. 

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In order to obtain the full benefit of harmonic cancellation the two bridges must be controlled in a common manner. The control system will enable the fundamental current in both supply lines of the same phase to be in-phase, i.e. the star primary line current must be in-phase with the delta primary line current. See Reference 12, Chapter 3 which emphasises this aspect. The controlled firing of the delta-star bridge T cancels the 30° degree phase shift of the transformer. From the Fourier analysis point of view this can be achieved by adding a + 30° phase shift to the delta primary line current. 

The magnitude of the two parts is divided by 3 to obtain the primary line current of the delta-star transformer. The result is then added to the hue current of the star-star transformer. The total magnitude of the supply line harmonic coefficient nsum is given by. 

EDLs are very intense, stable emission sources. They provide better detection limits than HCLs for those elements that are intensity-limited either because they are volatile or because their primary resonance lines are in the low-UV region. Some elements like As, Se, and Cd suffer from both problems. For these types of elements, the use of an EDL can result in a limit of detection that is two to three times lower than that obtained with an HCL. EDLs are available for many elements, including antimony, arsenic, bismuth, cadmium, germanium, lead, mercury, phosphorus, selenium, thallium, tin, and zinc. Older EDLs required a separate power supply to operate the lamp. Modern systems are self-contained. EDL lamps cost slightly more than the comparable HCL. 

Backup supplies are always useful when a utility is lost Spare equipment or multiple-train equipment may be used in order to keep the utility on line even if one part of the system shuts down. An alternative or supplement is to provide backup from a different utility system. The number of different air systems found in a plant provides an opportunity to do this. Moreover, nitrogen can be used to back up some of the air systems. All these tie-ins require careful review during hazard analyses. Usually, the backup supply is activated when the primary supply loses a certain amount of line pressure. If this is done by means of a single pressure regulator and the pressure is also low on the backup system, the flow may be opposite to that intended. It is essential to keep nitrogen out of an air supply to a confined, inhabited space (e.g., the instrument air supply to a control room), and it is essential to keep air out of nitrogen when it is used as an inert gas. 

Primary Pusip Steam Supply Pressure monitors located on supply lines to the five process pumps 2/5 Loss of steam to two or more puzDps. 

Both the primary coolant loop and the moderator coolant system have a role in the confinement system. Check valves have been installed in the primary loop on the inlet supply lines and on the return lines Just downstrecun of the dump valves, as shown in Figure 7-5 In case of a line rupture and failure of the last-ditch coolant systems, these valves will force a portion of the water in the loop to flow through the reactor before leaving the break. lhis point is critical. It is necessary that Interim cooling be provided to prevent fuel melting until steam venting is completed. 

The second installation of the FlammaTec burners on Furnace A was implemented with separate gas supply lines to each burner and with continuous flow measurement on both the primary and secondary fuels. This enabled Libbey to remotely and independently control each of the gas flows to the burners from their control room. 

Many shop fabricators are capable of supplying prefabricated components of these systems. However, because of the numerous material combinations one may be faced with, consideration should be given to work ing with vendors who specialize in providing this service. FRP, lined, and PVC pipe are just a few examples of available prefabricated double-containment piping systems. Primary drain lines, sometimes called carrier pipes, come fully fabricated with supports within the secondary pipe or containment line. This service greatly reduces field installation time that can translate into significant co.st savings. 

Demineralizer Inlet Primary Heat Exchanger Inlet Primary Heat Exchanger Outlet Secondary Heat Exchanger Inlet Secondary Heat Exchanger Outlet Cooling Tower Supply Line Cooling Tower Return Line... 

When the primary of a three-phase two-winding transformer, having its secondary wound for a three-phase open delta, is connected across an unbalanced supply system, a residual voltage across the open delta will appear. This is the principle on which this transformer is based (Figure 15.4(a)). As discussed in Section 21.2.2, and illustrated in Figure 21.7, the phasor sum of all the three line to ground voltages in a three-phase balanced system is zero, i.e. 

Rated primary voltage The normal practice for an HT system is to provide a separate LT feeder for the auxiliary supplies. The primary voltage will be the normal system voltage, V, when the transformer is connected line to line or V,/ l3 when connected line to neutral. 

Regarding fires, water is the primary extinguishing agent, and it should be available in adequate supply and pressure at all of the locations in the plant. The layout for various types of installations and the appropriate recommendations are found in the standards of the National Fire Protection Association. Fire hydrants, hose lines, automatic sprinkler and water spray systems should all be a part of the permanent equipment facilities of the plant. 

Laboratory rooms intended for toxic work should be provided with adjacent shower and change facilities. The layout must not require freshly showered personnel to track back through the area that they might have just contaminated. All drains, including those in laboratory floors, should have deep traps and be directed to a toxic sump. Airlocks will help prevent toxic fumes from spreading to non-toxic areas in the event of a failure of a primary containment cabinet. Check valves in the incoming water lines will prevent contamination of potable water supplies when pressure is lost. 

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