Pressure indicators, cost

The range of total pressure indicated in the graph corresponds to the lowest value at which the condensation of H20/dioxane vapors is feasible by using cooling water at a maximum temperature of 35°C (as in when using water from the cooling tower), namely, without the extra cost of energy for the eventual production of chilled water. 

Figure 3.5. Vacuum control with steam jet ejectors and with mechanical vacuum pumps, (a) Air bleed on PC. The steam and water rates are hand set. The air bleed can be made as small as desired. This can be used only if air is not harmful to the process. Air bleed also can be used with mechanical vacuum pumps, (b) Both the steam and water supplies are on automatic control. This achieves the minimum cost of utilities, but the valves and controls are relatively expensive, (c) Throttling of process gas flow. The valve is larger and more expensive even than the vapor valve of case (a). Butterfly valves are suitable. This method also is suitable with mechanical vacuum pumps, (d) No direct pressure control. Settings of manual control valves for the utilities with guidance from pressure indicator PI. Commonly used where the greatest vacuum attainable with the existing equipment is desired.

Cost of equipment (Cont.) platforms, 711 pressure indicators, 814 pressure vessels, 539-542 pumps, 526-527 reactors, 730-732 reboilers, 731... 

Due to the low bum-up of the fuel firom the pressurized heavy water reactors, storage in transport containers has been chosen. Design studies for reinforced concrete casks with stainless steel lining indicate cost of around US 45 per kg uranium. At present pools and concrete silos assure the interim at-reactor storage. If rq>rocessing is decided, then the plant would also be installed in the proximity of the disposal site to minmiize risks and costs of transportation. 

All organizations have to focus on a mere handful of key indicators and key issues in order to coordinate diverse employees. Said differently, organizations have to ignore most of what they see in order to get work done (Turner, 1978). If people focus on information that supports expected or desired results, then this is simpler than focusing on anomalies, surprises, and the unexpected, especially when pressures involving cost, schedule, and efficiency are substantial. Thus, if managers believe the mission is not at risk from a debris strike, then this means that there will be no delays in the schedule. And it also means that it makes no sense to acquire additional images of the shuttle. 

Effective and well planned maintenance can reduce the operating cost of your pumps and other ec]uipment as this example demonstrates. With differential pressure gauges on the pump, an amp meter and flow meter you can determine if strict tolerance parts arc worn. This indicates the need to take the pump into the shop for corrective procedures. If you don t do it, you are wasting your annual operating budget. As we mentioned in Chapter 6, the Wear Rings should be called Efficiency Rings. Now you know why. 

A modification of the HAT cycle has been proposed by Nakhamkin [11], which is known as the cascaded humid air turbine (CHAT). The higher pressure ratios required in humidified cycles led Nakhamkin to propose reheating between the HP and LP turbines. Splitting the expansion in this way is paralleled by splitting the compression, and enables the HP shaft to be non-generating, as indicated in Fig. 6.15. This implies that the capital cost of the plant can be reduced, but the cycle is still complex. 

This concept can be especially significant for a low-pressure vessel wl minimum wall thickness is desired. For example, assume the caiv .,.i i.ons for a 50-psig MAWP vessel indicate a wall thickness of 0.20 in., and it is decided to use K-in. plate. This same plate might be used if a MAWP of 83.3 psig were specified. Thus, by specifying the hi MAWP (83.3 psig), additional operating flexibility is available at e dally no increase in cost. Many operators specify the MAWP based on... 

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