Gasless Delay Elements and Detonators

Gasless delay assemblies fall into two general types, obturated and non-obturated. 

The choice of type usually depends upon the method of initiation. For example, the 

Fig 1-56 OBTURATED GASLESS DELAY ELEMENT FOR 4 TO 6 SECONDS PERCUSSION DETONATOR 

In Fig 5-44 of Ref 23 (See our Fig 1-57) is shown a delay element which is assembled within a single housing as an integral part of Flame Initiated 0.10 Second Flash Delay Detonator. Its igniter mixture is probably M31 (Pb sulfocyanate 45 K chlorate 55%) (Ref 23, p 2-10) the delay compn is either HP-25 or D-5 the intermediate chge is LA and the base chge is RDX 

Fig 1-5 FLAME INITIATED 0.10 SECOND FLASH DELAY DETONATOR 

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Gasless Delay Elements and Detonators Employing Them. See Vol 4 of Encycl, Section 4, Part F, pp D863-R to D868-R... 

Delay elements, gasless, and detonators employing them 4 D863... 

The delay detonator (Figure lb) uses lead azide as the output charge and converts and augments the heat fiom a gasless delay column to a detonation. The small amount of azide used in this example would require the use of a relay or flash detonator as the next element if the sequence is to terminate in the detonation of a secondary explosive. Otherwise the output from the 20 mg of lead azide is adequate only to ignite a sensitive pyrotechnic or another lead azide charge. 

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