Safe separation distance

Provide safe separation distances for normal operation, maintenance, emergency egress, ergonomics... 

Ignition of flammable Provide safe separation distances release resulting in fire. Develop appropriate area electrical or explosion. classification Provide ignition source control Place ignition sources in positive pressure enclosure and buildings Provide adequate ventilation API RP500 BS 5345 BS 5958 NFPA-70 NFPA-77... 

Provide safe separation distances Install fixed fire protection and alarms, water sprays (deluge), and/or foam systems activated by flammable gas, flame, and/or smoke detection devices... 

The purpose of this program is to establish safe separation distances relative to explosive end-items and in-process materials, as well as critical and safe depths of bulk explosives on conveyors, hoppers, tubes, or other transfer lines. 

Crocker and Napier (1986) provide tables of thermal impact zones from common situations of tank roof and ground pool fires. From these tables, safe separation distances for people from pool fires can be estimated to be 3 to 5 pool diameters (based on a safe thermal impact of 4.7 kW/m ). 

The acknowledged safe separation distances are detailed in Table 8.3. 

Safe separation is a term used to reflect the safe distance between two objects under parameters and conditions. For example, the safe separation distance for an artillery round is the distance from the gun barrel exit to the point of detonation where the detonation fragments will not affect friendly forces or the firing forces. 

These battery-limit, unit isolation valves should be clearly identified and installed in easily accessible locations that are a safe distance from potential fire sources. Generally, 25-50 ft (8-15 m) provides an acceptable separation distance. These isolation valves can also be used for turnaround purposes and should be located at or near ground level. 

Safe separation studies were conducted to achieve increased production and cost effectiveness with improved safety. A typical ammunition production line flow diagram (in this case for the manufacture of 105 mm projectile) consists of several work areas as shown in Fig 8. ( (l) Receiving and storage, (2) Box open and inspect (3) Melt Pour (U) Cool (5) Hold (6) Funnel Pull and (T) Riser Preparation.) Explosive material is transferred by automatic conveyor between these work areas. The requirement was to establish safe separation between explosive boxes, pallets with and without funnels, buckets, and to determine critical height of continuous feed flake Comp B and TNT. The objective of these tests was to establish minimum nonpropagation distances between these items so that an explosion chain reaction will be prevented. 

The entropy of activation, which includes a contribution from the separation distance dependence of the electronic coupling is given by Eq.7. It is seen that the increase in rate in V31W azurin follows from a more favorable entropy of activation (Table I), which is larger by 16.8JK mol compared with WT azurin. Since AS° can safely be assumed to be the same for intramolecular ET in... 

The results of the above-listed analyses are used to determine the exclusion zone—the area outside of which is considered safe for public access. The results are also used to determine in-plant separation distances. The hazards study must be conducted before finalizing the relative locations of storage tanks, liquefaction facilities, and other power plant facilities. From a capital cost viewpoint, these facilities should be kept as close as possible to each other however, safety considerations mandate minimum safe distances an3 vhere between 200 and 800 m. Enlarging the exclusion zone by 1 to 2 km from any public facility such as a school, a hospital, or a highway may be necessary. 

If separate blast sources are located close to one another, they may be initiated almost simultaneously. Coincidence of their blasts in the far field cannot be raled out, and their respective blasts should be superposed. The safe and most conservative approach to this issue is to assume a maximum initial blast strength of 10 and to sum the combustion energy from each source in question. Further definition of this important issue, for instance the determination of a minimum distance between potential blast sources so that their individual blasts may be considered separately, is a factor in present research. 

Physical Separation. In addition to providing electrical isolation, it is necessary to provide physical separation to ensure the non-hazardous circuits can not degrade the intrinsically safe portion of the circuits. This can be accomplished by planning the physical layout to incorporate the use of distance, enclosures, partitions, separate raceways, and insulation. The final physical layout selected should meet or exceed the requirements of Chapter 3, Sections 1, 2, 3, and 4 of NFPA 493. 

In recent years, a dependable dipole function for He-Ar, last column of Table 4.3, has been obtained [278] which we compare with the universal dipole function mentioned [23], Fig. 4.5. The He-Ar interaction potential is one of the better known functions [13] and suggests Rmj = 6.518 bohr. Both functions were normalized to unity at the separation R = 5 bohr in the figure. The comparison shows that at small separations the logarithmic slope of the most dependable dipole function is roughly one half that of the universal p, and p diverges rapidly from p(R) for R — o. Similar discrepancies have been noted for other rare gas systems (Ne-Ar, Ne-Kr, and Ar-Kr [152]). Even if for these other systems the dipole function is not as well known as it is for He-Ar, it seems safe to say that for the rare gas mixtures mentioned the induced dipole function is definitely not identical with the universal function at the distances characteristic of the spectroscopic interactions the universal dipole function is not consistent with some well established facts and data. We note that the ratio of // (/ ) and the He-Ar potential is indeed reasonably constant over the range of separations considered (not shown in the figure). 

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