SAFE charts

One method used to summarize the required devices and show the function performed by each device is with a function matrix. Figure 14-4 is a completed function matrix chart for the simple process flow diagram shown in Figure 14-5. The function matrix is from RP I4C and is called a SAFE chart. Each component is listed in the left hand column with an identification number and description. Under Device I.D., each of the devices listed in the SAC is listed. If the device is not present, the appropriate SAC reference number is listed. If the SAC rationale requires that another device be present on another component, that device is listed under Alternate Device, if applicable. 

Figure 14-4. Safety analysis function evaluation (SAFE) chart for process flow in Figure 14.5.

Cause and effects charts (SAFE charts) with schedule of alarm and trip settings. ... 

Marked items marked are considered minimum data required for a HAZOP or What-If review to occur. This data basically contains the layout (plot plan) of the facility, the process design (P ID and process description) and how it will be controlled during an emergency (SAFE chart and fire protection plant). With this information the "experts" can understand the design and operating principles of the facility. Since the emergency isolation, depressurization and fire protection features are provided, it can be readily deduced how the facility will fare from a catastrophic incident. 

Create a Safety Analysis Function Evaluation (SAFE) Chart. This is a chart showing all process components and their required safety devices. 

As can be noted in Figure 21.7.2, steam and ediane are mi.xed before entering die reactor tubes where pyrolysis reacdons take place. All feed and product lines must be equipped with appropriate control devices to ensure safe operation. The FTA flow chart breaks down a TOP event (see descripdon of fault tree in Unit II) into all possible basic causes. Aldiough, diis mediod is more structured than a PHA, it addresses only one individual event at a dine. To use an FTA for a complete liazard analysis, all possible TOP events must be identified and investigated this would be extremely time consuming and perhaps urmecessary in a preliminary design. 

Catalog chart Table 12-14D indicates that the safe speed of the fan is 2,770 rpm and the catalog chart. Table 12-14, indicates a 1.0 factor for the standard steel wheel at 300°F. The fan is satisfectory to operate at 2,447 rpm. 

Chart II Temperature Correction Factors for Maximum Safe Speeds of LS or RIM Wheels... 

Chart III Temperature Corrections Factors for Maximmn Safe Speeds of DH Wheels... 

Sizing, 451, 453, 455, 459, 462 Sonic flow, 461 Types, illustrations, 411-421 Rupture disk, liquids, 462, 466 Rupture disk/pressure-relief valves combination, 463 Safely relief valve, 400 See Relief valve Safety valve, 400, 434 Safety, vacuum, 343 Scale-up, mixing, 312, 314—316 Design procedure, 316-318 Schedules/summaries Equipment, 30, 31 Lines, 23, 24 Screen particle size, 225 Scrubber, spray, 269, 270 Impingement, 269, 272 Separator applications, liquid particles, 235 Liquid particles, 235 Separator selection, 224, 225 Comparison chart, 230 Efficiency, 231... 

In 1972 a paper on venting by Huff 2J documented concerns that many designers suspected that to truly be safe the vent sizing of many systems should be based on assuming two-phase flashing flow in the vent system. A two-phase flow vent method developed by Huff was compared with Boyle s all-liquid method, and values from the FIA chart in Figure 2. It can be seen that under many conditions, previous methods were not... 

The accurate assessment of binary chemical compatibility is an important part of the safe handling, transport and processing of industrial chemicals. The most common and convenient way to represent binary chemical incompatibility is by a simple two-dimensional chart or matrix. Binary compatibility charts are an extremely useful teaching tool for new and even veteran employees. 

The search for Gd(III) complexes with an increased number of inner-sphere water molecules (q > 1), though sufficiently stable to be safely used in vivo has led to consider the model compounds shown in Chart 6. The relaxivity values of these complexes are significantly higher with respect to the Gd(III) chelates of similar size and q = 1. By taking as reference the ri values of [GdD0TA(H20)] and [GdDTPA(H20)] (4.7 s-VM ), the... 

The relevance of Fig. 5.11 to the problem of setting control chart limits on means is that if one is furnished with a description of the typical pattern of variation in y, sensible expectations for variation in y follow from simple normal distribution calculations. So Shewhart reasoned that since about 99.7 percent (most) of a Gaussian distribution is within three standard deviations of the center of the distribution, means found to be farther than three theoretical standard deviations (of y) from the theoretical mean (of y) could be safely attributed to other than chance causes. Hence, furnished with standard values for /x and a (describing individual observations), sensible control limits for y become... 

The product of this 8 year systematic study was the publication of the safety design manual entitled, "Structvires to Resist the Effects of Accidental Explosions" (Army s Publication TM5-1300). An outline of studies leading to publication of this manual is shown in Fig 1. The manual contains procedures, charts, and tables required to establish the environment of an explosion and its output in terms of blast and fragments. The relations are presented in such a manner that the type of protective structure may be selected, analyzed, and designed to provide a safe level of protection for personnel, equipment, and for separation of potentially mass detonating materials. 

A system has been devised to store acetonitrile safely at high pressures and temperatures. The acetonitrile is contained in a 0.2-ft tank maintained at 4500 psia and 550°F. This tank is placed inside a second tank whose volume, excluding the volume of the first tank, is 2 ft Nitrogen at 10.0 atm and 550 F is contained in the second tank. Use the compressibility chart to estimate the final system pressure (atm) if the first tank ruptures and the final system temperature is 550°F. The critical temperature and pressure of acetonitrile are 548 K and 47.7 atm, respectively. 

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