Blast resistance

Hardness. Glass hardness tests usually measure the resistance to abrasion by grinding or grit-blasting, resistance to scratching, or penetration by an indenter. The method to be used depends on expected service conditions. Knoop hardness (Table 4) is commonly used, because other methods usually fracture the glass. 

Tayout also has a significant role in minimizing the probability of ignition of a flammable release. Area electrical classification provides the basis for the control of electrical ignition sources. This classification is also used to determine the areas that require protection from vehicular access, etc. Frequently, highly hazardous processes that can result in overpressure (e.g., hydrogenation) are placed behind blast resistant structures/walls. 

Transportation accidents were analyzed. An aircraft could directly impact the reactor. The K-Reactor is >20 miles from an airport, not on an airway and built with blast resistant construction. The nearest public highway is 2 miles away, the nearest pipeline 17 miles away, the nearest public... 

If, on the other hand, a vapor cloud s explosive potential is the starting point for, say, advanced design of blast-resistant structures, TNT blast may be a less than satisfactory model. In such cases, the blast wave s shape and positive-phase duration must be considered important parameters, so the use of a more realistic blast model may be required. A fuel-air charge blast model developed through the multienergy concept, as suggested by Van den Berg (1985), results in a more realistic representation of a vapor cloud explosion blast. 

The motor control center (MCC) and Substation have concrete block load bearing walls of ordinary construction. The control house is of blast resistant construction with reinforced concrete walls and roof designed for 0.2 bar static. All three buildings are 4 m tall. 

An American Society of Civil Engineers (ASCE) document titled "Design of Blast Resistant Buildings in Petrochemical Facilities" (Ref. 9) is currently being developed. 

For screening purposes, however, the analysis has shown that a building of low blast resistance and high episodic occupancy, and that is potentially impacted by three different process units may present an undue aggregate risk and should be evaluated further. In retrospect, this conclusion should have been obvious without the need to resort to the risk-screening analysis. 

The overpressure-consequence relationship in Table 5.3 is given for typical buildings of ordinary construction (i.e., not blast-resistant design). This qualitative characterization of consequences does not explicitly account for the specific structural characteristics of a particular plant building nor does it account for the impulse or duration of the blast wave. As a result, the... 

Increase the blast-resistance capabilities of windows by replacing glass with polycarbonate or laminated safety glass and, where necessary, upgrading frame design and attachment to walls... 

Eliminate windows by filling in window openings with more blast-resistant structural materials... 

Replace doors and frames with those of blast-resistant construction... 

Build a blast-resistant protective shell that encapsulates the existing building... 

An option for upgrading blast resistance of an existing building may be to provide additional beams, columns, or walls strengthened with a mortar or concrete pneumatically projected at high velocity onto a surface. The concrete is placed on a cage of reinforcement, which is doweled into elements of the existing stmcture. 

For low-hazard situations, blast-resistant design is not required because a fire is more likely than an explosion in case of a flammable vapor release. Where little or no explosion hazard (low hazard) exists, it is only necessary to meet conventional building code requirements, including those for fire protection. 

Their technical expertise is evident throughout the book, especially in the risk evaluation (Chapters 2-6) and explosion and fire phenomena and principles of blast-resistant design (Appendices A and B). 

Denver, Colorado (Refs. 16 and 19) 3 (0 in buildings) A propane release at a polymerization unit in a process plant resulted in a blast that destroyed the process unit. The blast-resistant control house, located only 98 ft (30 m) from the blast center, sustained little damage. 

The control room discussed in Example 2 is located 150 ft (45 m) from the nearest process equipment in the unit. Since the building occupancy exceeds the company criteria, further evaluation is required. The building was designed to be blast resistant to 5 psi (0.34 bar). 

One risk-reduction option is to construct a new blast-resistant building in the same location as the existing building. This involves demolishing the existing building, which may cause significant disruption to process plant operations. 

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