Explosion-Proof Tools and Their Applications (Part 2)

3. Selection and use of explosion proof tools

(1) It is meaningless to use explosion-proof hand-held tools on the Vietnamese side with petroleum and other hydrocarbon vapors. Because the energy of the spark produced when the iron hits or rubs is small, it is not enough to ignite these combustible gases. The American Petroleum Institute (API) believes that when dealing with petroleum or natural gas, which has a high ignition temperature, whether it is copper-plated tools or iron tools, there is no advantage or disadvantage: only when dealing with carbon disulfide, ether, ethyl For aldehydes and other substances with low ignition energy at an ignition temperature of 200C, copper-plated tools have a fireproof effect.

(2) When dealing with hydrocarbon-based gases or liquids, the use of iron tools and copper tools have the same safety effect, and the use of iron tools is economical.

(3) In the presence of acetylene. The use of copper tools is prohibited. Because acetylene and copper can be in contact with a strong chemical reaction, pink explosive copper acetylene is generated. Acetylene steel is subject to vibration and friction, and it is very easy to cause an explosion when the temperature is 120 ~ 180C. It should be pointed out that most of the tools made of non-ferrous materials are not ideal in mechanical performance and have different explosion-proof performances.

It must be reliable. Some steel tools are coated with a layer of non-ferrous metal, because the working parts are often easily worn, and in the case of magnetic collision, the steel surface can be exposed, so the explosion-proof performance is not reliable. Therefore, we must pay attention to the selection of explosion-proof tools. ①No matter what kind of non-sparking tools can only reduce the risk of tool sparks, but not eliminate sparks, from this point, the application of anti-spark tools is only a conservative safety measure; Easy to break, short life, low cost, poor economy; ③ In use, some metal particles with high hardness will be embedded in its working surface. Before use, these impurities must be checked and eliminated. All these have affected the use-value and effect of explosion-proof tools.

Explosion Proof Hand Tools

4. Regulations and standards of explosion proof hand tools

In order to prevent explosions and fire accidents caused by sparks from hand-held tools, many countries attach great importance to the production and management of explosion-proof tools and have formulated corresponding regulations and standards.

The Japanese Fire Protection Law clearly states:

"In places where flammable liquids, flammable vapors, or flammable gases leak or are in danger of staying and where flammable dust floats in danger, no mechanical appliances, tools, etc. that can generate sparks shall be used."

China ’s “Electrical Safety Regulations for Explosive Hazardous Locations (Trial)” formulated on December 16, 1987 clearly stipulates that the use of tools and appliances that generate impact sparks is strictly prohibited when maintaining and inspecting equipment in explosive hazardous locations.

The “Warehouse Fire Safety Management Rules”published in August 1980 stipulates that “Handling of chemical combustible materials must be handled with care. Vibration, impact, heavy pressure, friction and inversion are strictly prohibited. The use of tools that generate sparks is not allowed. Wear shoes with iron nails and install a reliable grounding device on equipment that may generate static electricity "

The product standards for China's explosion-proof tools were formulated in 1986, approved in 1988, and implemented on December 1, 1989.