Subsystem piping

All instrument tubing and subsystem piping should be arranged to allow free aeeess to expander and major auxiliary equipment for operation and maintenanee. 

In die simulation model, die FCC system was subdivided into discrete elements and suitable subsystems. This model provided all die process parameters such as pressures, flowrates, and temperatures. Figure 6-44 shows die corresponding block diagram. (The model for die expander, piping systems, and vessels is based on a gas turbine model described by GHH Borsig in a paper by W. Blotenberg.)... 

The Seismic Safety Margins Research Program developed a computer code called SMACS (Seismic Methodology Analysis Chain with Statistics) for calculating the seismic responses of structures, systems, and components. This code links the seismic input as ensembles of acceleration time histories with the calculations of the soil-structure interactions, the responses of major structures, and the responses of subsystems. Since uses a multi-support approach to perform the time-history response calculations for piping subsystems, the correlations between component responses can be handled explicitly. SMACS is an example of the codes that are available for calculating seismic response for PSA purposes. 

Hot water generators are the simplest systems overall, although many larger institutional and commercial hydronic heating plants contain fairly complex distribution systems that may include high and low flow rate subsystems and primary and secondary piping schemes in either series or parallel configurations. 

All subsystems influence the integrated in-sewer processes, although the water phase processes are typically most important. Reaeration is a process that, when there are low DO concentrations in the wastewater, limits the rate of the aerobic processes (cf. Example 5.1). The relative importance of the processes in the suspended water phase and in the biofilm may vary, e.g., determined by the area/volume ratio of the sewer pipe. 

In this approach accident cases and design recommendations can be analysed level by level. In the database the knowledge of known processes is divided into categories of process, subprocess, system, subsystem, equipment and detail (Fig. 6). Process is an independent processing unit (e.g. hydrogenation unit). Subprocess is an independent part of a process such as reactor or separation section. System is an independent part of a subprocess such as a distillation column with its all auxiliary systems. Subsystem is a functional part of a system such as a reactor heat recovery system or a column overhead system including their control systems. Equipment is an unit operation or an unit process such as a heat exchanger, a reactor or a distillation column. Detail is an item in a pipe or a piece of equipment (e.g. a tray in a column, a control valve in a pipe). 

This consists of vacuum pumps, pipes, valves and connections, etc. This subsystem is used to evacuate the gases and control the pressure within the reaction chamber. 

Fuel subsystem, including tank for hydrogen, piping, valves and controls to deliver the hydrogen fuel at the required pressure mass flow and humidity to the fuel cell stack. 

The model had been originally proposed for a buried pipeline. The basic concept of the model was to divide the pipe and its surroundings into components and subsystems (Figure 4.50) and evaluate the risk of corrosion (and MIC) for each. 

FIGURE 4.50 (See color insert.) Subsystems of a buried pipeline as a system (system = pipe, internal subsystems including flnid and lining conditions, external subsystem including the coating and soil conditions). 

Two different types of solenoid valves are used to block fuel flow to a burner in a SIS. The valves are piped in series. Both valves should close when a dangerous condition is detected. Both valves have one failure mode, fail-danger, with a failure rate of 0.0008 failures per year. Both valves are tested once every year. Based on the differences between the valves, a common cause beta factor of 0.01 is assigned. What is the PFD of the valve subsystem including common cause ... 

The unloading of tankers is performed at the pier placed in the Port of Gd3mia. The pier is connected with terminal part A through the transportation subsystem built of two piping lines composed of steel... 

The capacities of the emergency core cooling systems suffice to provide water under all postulated pipe break conditions. This statement is also valid assuming that only two of the four redundant subsystems are operable. The postulated loss-of-coolant conditions include a hypothetical 80 cm leak at the bottom of the reactor vessel In this context, it can be noted that the capacity of the low pressure coolant injection punq)S has been reduced for BWR 90, following comprehensive core cooling analyses. As a secondary effect, it has been possible to simplify the auxiliary power supply systems. 

The RH consists of two independent, redundant mechanical subsystems, each of which receives electrical power from one of two separate and redundant electrical power trains. Each subsystem consists of one RHR pump one RHR heat exchanger and the required piping, valves, and instnunentation. The RHR pumps and heat exchangers are located in... 

A sodium leak detection system provides early warning of any sodium-to-air leaks from the IHTS piping. In the event of an SG tube leak, the sodium-water reaction pressure relief subsystem (SWRPRS) provides overpressure protection of the IHTS and IHXs. The SWRPRS consists of a safety-grade rupture disk, a sodium dump tank, a cyclone/separator tank, a vent stack, and a hydrogen igniter. To separate the reactants, the SWRPRS also initiates the water-side isolation of the SGS and pressure relief. 

The typical ECCS for BWRs is also composed of three subsystems with equipment and flow path redundancy. The first subsystem is a high-pressure spray system that sprays water on the reactor core. For small pipe breaks, the high-pressure spray can maintain the water level in the reactor vessel so that the core remains covered. For larger breaks, this system cools the core by spraying water on the fuel rods. The second subsystem is a low-pressure spray system that delivers a large-volume water spray to the top of the core. The third subsystem is a low-pressure core injection system that provides a large flow of water to the reactor vessel to reflood and cover the core. 

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