Explosion protection principles

Due to the destructive nature of hydrocarbon forces when handled incorrectly, fire and explosion protection principles should be the prime feature in the risk philosophy of any hydrocarbon facility. Vapor cloud explosions in particular are consider the highest risk at a hydrocarbon facility. Disregarding the importance of protection features or systems will eventually prove to be costly both in economic and human terms should a catastrophic incident occur without adequate safeguards. 

D.P. Nolan, Handbook of Fire and Explosion Protection Principles for Oil, Gas, Chemical and Related Facilities, third ed., WiUiam Andrew/Elsevier Pubhcations, New York, NY, 2014. 

Preventive Explosion Protection The principle of preventive explosion protection comprises the reliable exclusion of one of the requirements necessary for the development of an explosion. In pictorial terms, therefore, at least one of the sides of the hazard triangle shown in Figure 26-33 will be broken open. 

FIG. 26-33 Hazard triangle principle of preventive explosion protection. 

EXPLOSION PROTECTION ENGINEERING PRINCIPLES FOR OIL, GAS, CHEMICAL, AND RELATED FACILITIES... 

Handbook of fire and explosion protection engineering principles for oil, gas, chemical, and related facilities / by Dennis P. Nolan, p. cm. 

This book in not intended to provide in-depth guidance on basic risk assessment principles nor on fire and explosion protection engineering foundations or design practices. Several other excellent books are available on these subjects and some references to these are provided at the end of each chapter. 

The protection principle of pressure relief is based on limiting the pressure to which equipment might be exposed by the removal of gaseous or multi-phase material flows from, in the case of an explosion or a runaway reaction by allowing certain predetermined openings to be opened in such a way that the pressure in the vessel does not exceed a predetermined permitted value. 

A very generalized principle of an intrinsically safe electric circuit is shown in Fig. 6.169. Power source, voltage and current limitation are located in a safe area or shall be explosion protected (e.g. in a flameproof enclosure) if located in a hazardous environment. The electric circuit entering the hazardous area as an intrinsically safe circuit is not capable of producing ignitable sparks at make or break. 

In principle, intrinsically safe apparatus do not need an enclosure since explosion protection is inherent due to the design of the circuitry. In cases where intrinsic safety - i - may be adversely affected by any access to live parts (e.g. infallible creepage distances in air), an enclosure ensuring an IP code of (at least) IP 20 (according to IEC 60529) shall be fitted. 

To clarify things neither type tests and verifications nor routine tests are the point of this chapter, but inspection and maintenance procedures after installation and before or during service. These procedures shall be done -and this is a general rule - by qualified personnel, who are experienced in the various types of explosion protection, installation practices and rules and the principles of area classification. 

This bibliography does not claim to be complete. It deals with basic principles and essential subsections in the field of explosion protection. 

This book is intended for engineers, scientists, plant safety personnel and for students in the field of electrical engineering to give an introduction to the basic principles of explosion protection and the relevant protection techniques. 

Protection principles focus on the ways and means to exclude equipment and components as ignition sources. Ignition sources are prevented in explosion protected equipment by selecting appropriate materials and by constmctive measures. Another way is to limit the energy level from the equipment to prevent explosion. All these must be verified and confirmed by the appropriate tests. 

Generally, four protection principles as detailed in Fig. X/3.5.1-1 are used to prevent equipment from any explosion by protecting it and limiting its energy so that it cannot become a source of ignition. In all the protection principles depicted in Fig. X/3.5.1-1, it is necessary to ensure that an explosive atmosphere must not be able to reach nonpermitted temperatures with respect to the ignition temperature of substances present in the surrounding atmosphere. The alternative is that all... 

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