Ignition sources table

Plant design and procedures should be examined for potential ignition sources. Table 2-2 shows the results of an investigation of over 25,000 fires [10]. 

Flash points and autoignition temperatures are given in Table 11. The vapor can travel along the ground to an ignition source. In the event of fire, foam, carbon dioxide, and dry chemical are preferred extinguishers. The lower and upper explosion limits are 1% and 7%. 

The ignition temperature is the minimum temperature required to initiate or cause self-sustained combustion. Table 2 also Hsts ignition temperatures of several common ethers. Attention is directed to the particularly low ignition temperature of ethyl ether, especially with reference to some common ignition sources such as a lighted cigarette (732°C) or a pressurized (0.7 MPa or 100 psi) steam line (180°C). 

Detonation arresters are typically used in conjunction with other measures to decrease the risk of flame propagation. For example, in vapor control systems, the vapor is often enriched, diluted, or inerted, with appropriate instrumentation and control (see Effluent Disposal Systems, 1993). In cases where ignition sources are present or pre-dic table (such as most vapor destruct systems), the detonation arrester is used as a last-resort method anticipating possible failure of vapor composition control. Where vent collec tion systems have several vapor/oxidant sources, stream compositions can be highly variable and... 

Table 6.4 Approximate temperatures of common ignition sources...

A material that is above its autoignition temperature will ignite spontaneously on contact with air in the correct proportions (see Table 6.1 for minimum temperature of ignition source). 

Certain materials which are generally considered to be stable at ordinary temperatures can inflame even in tlie absence of normal ignition sources. Such spontaneous combustion results from exotliermic autoxidation when the heat liberated exceeds that dissipated by the system. Materials prone to self-heating are listed in Table 6.7. In most cases, such fires involve relatively large, enclosed or thermally-insulated masses, and spontaneous combustion usually occurs after prolonged storage. 

Outside the storage area or the space covered by any roof up to 1.5 m above ground level and within the distance set out for a fixed source of ignition in Table 9.17, column 3. 

TABLE 7.4.3 Influence of tlie Type of Ignition Source and of tlie Ignition ... 

These can be readily ignited by flames, sparks, static electrical discharges (often the most likely), hot surfaces, and many other sources. Table 7-31 lists dust cloud ignition temperatures ranging from 572°F to 1112° F, and can be contrasted to flammable vapor-air ignition temperatures from 428° F to 1170°F. Generally, ignition tempera-... 

Combustion is generally initiated by the introduction of a finite amount of energy to raise a finite volume of the material to its ignition temperature. Potential ignition sources for vapour—air mixtures are listed in Table 5.3, and temperatures in Table 5.4. They include ... 

If a significant volume of gas (caused by a leak, for example) is exposed to an ignition source and this gas is mixed with air in proportions that are close to stoichiometric, the gas cloud can cause a lot of damage when it gives rise to a detonation. The accident at Flixborough is one example. The lower explosive limit of hydrocarbons is extremely low. If the carbon chain length exceeds 8, the autoinflammation temperature of a linear hydrocarbon is close to 200°C. All these parameters decrease with pressure. The table below shows to which extent pressure influences the AIT of ethylene ... 

INTERLINERS. These are intended to protect the filling against specified flammable cover fabrics. Interliners are tested with ignition source 5 over a standard PU foam to BS5852 Part 2. FR treated interliners shall be subjected to the specified water soak before testing Table VI. 

ALL FILLING MATERIALS EXCEPT PU SHEETS OR BLOCKS. These are tested against ignition source 2 which is a butane flame, approximately 120 mm high and applied to the FR polyester fabric covered filling for 40 seconds(Table VII) to BS 5852 part 2. This applies to all loose foam and non-foam filling when tested singly. 

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