Explosion-proof tools are all knowledgeable: not all copper alloy tools are called explosion-proof tools

The material of the explosion-proof tool is copper alloy, due to the good thermal conductivity of copper and almost no carbon characteristics, so that when the tool and the object are rubbed or impacted, the heat generated in a short time is absorbed and conducted, and the other reason is that the copper itself is relatively soft, and there is a good concession when friction and impact, and it is not easy to produce tiny metal particles, so we can hardly see the spark, so the explosion-proof tool is also called a non-spark tool. The materials used to manufacture explosion-proof tools must be tested by national authoritative testing institutions according to GB10686-89 non-spark. After the non-detonating gas inspection is qualified, the chemical composition, explosion-proof grade and mechanical strength of the qualified material shall be clearly marked in writing in the official letter of the test report and disclosed to the user. Such explosion-proof tools are qualified and can be used with confidence. Not every ungraded copper alloy can be used to make explosion-proof tools. At present, there are two kinds of materials for the manufacture of explosion-proof tools at home and abroad, one is beryllium bronze alloy and the other is aluminum bronze alloy. The non sprking tools are made of beryllium bronze and aluminum bronze as raw materials, and the beryllium bronze alloy and aluminum bronze alloy do not spark when impacted or rubbed, which is very suitable for manufacturing safety tools used in explosive, flammable, strong magnetic and corrosive occasions. BeA-20C alloy withstood 561IJ of impact energy in 30% hydrogen or 6.5-10% methane air oxygen for 20 impacts without sparks and combustion.

Are copper tools explosion-proof? It is wrong to say that explosion-proof tools are made of "copper alloy" or "alloy copper". There are also some erroneous statements like copper wrenches, copper hammers, copper crowbars, and many more. Explosion-proof tools are tools used in flammable and explosive gas places, and are made of aluminum bronze and beryllium bronze alloy. Some erroneous names such as "copper alloy" or "alloy copper" also make small workshops use words to imitate explosion-proof tools, and to deceive users by taking advantage of the tools in terms of materials.

Explosion-proof tools are mainly beryllium bronze and aluminum bronze, because the copper itself is relatively soft, the hardness of copper tools is relatively poor, so generally do not make hardware tools alone.

Basic knowledge of the safe use of explosion-proof tools

1. What is an explosion-proof tool?

Explosion-proof tools, also known as safety tools, "non-spark tools", are mainly used in flammable and explosive places, where tools and working objects rub against each other and impact without sparks, effectively preventing flammable explosions.

Explosion-proof tools are irreplaceable safety tools in flammable and explosive places, friction and impact do not produce sparks, and have safe mechanical properties, good hardness and torque, no deformation in use, in line with the use value of the tool.

2. The main application fields of explosion-proof tools:

Explosion-proof tools are widely used in petroleum, chemical, oil production, gas production, oil and gas pipelines, power generation, mining, plastics, chemical fiber and other industries.

3. Material of explosion-proof tools:

Explosion-proof tools are divided into two materials: beryllium bronze and aluminum bronze.

(1) Beryllium bronze explosion-proof tools

Suitable for: Operation in hydrogen with a concentration of less than 21%. Standard code GB Ex II.C;

Surface color: golden yellow; non-magnetic; Hardness: 30-40 HRC;

Tensile strength: 1117N/mm²-1326N/mm²; Elastic limit: 840N/mm²-880N/mm²; Ductility: δ≤1.0%

(2) Aluminum bronze explosion-proof tools

Suitable for: Work in ethylene gas with a concentration of less than 7.8%. Standard code GB Ex II.B;

Surface color: silvery-yellow; micromagnetism; Hardness: 20-30 HRC;

Tensile strength: 782N/mm²-989N/mm²; Elastic limit: 450N/mm²-550N/mm²; Ductility: δ≥5%

4. Performance experiment:

In order to ensure the explosion-proof performance of explosion-proof tools, after the raw materials are smelted according to a specific ratio, the quality inspectors will extract them into test blocks and test rods, and according to the requirements of GB/T 10686-2013 standard, the drop hammer test and friction non-spark test will be done in hydrogen with a concentration of 21% in the highest grade ExIIC. Only when the sample is tested can the next step of production be carried out.

(1) Drop hammer no spark inspection

In a hydrogen environment with a concentration of 21%, the product is qualified if the 14KG hammer passes 20 impact drop tests at a height of 4M and does not detonate.

(2) Friction non-spark test:

In a hydrogen environment with a concentration of 21%, the sample is rubbed against the target at high frequency, and if no sparks are generated, the sample is qualified.

5. Don't confuse copper tools with beryllium bronze alloy explosion-proof non-magnetic tools?

Copper alloy tools can not be defined as explosion-proof tools, there are hundreds of specifications of copper alloys in the domestic market, as long as copper (electrolytic copper) and any metal synthesis is called copper alloy, the current explosion-proof tools are only made of beryllium bronze alloy and aluminum bronze alloyBoth materials are recognized by the market and also meet the performance, hardness, torque and mechanical strength of explosion-proof tools. In particular, copper alloys that do not have material reports are actually scrap copper purchased by the market, collectively referred to as miscellaneous copper (copper alloys). This material has high impurities, is easy to spark, has no hardness, no torque, is manufactured by the traditional sand casting process, has a rough surface, there are pores, trachoma, shrinkage porosity, easy to bend and break when used. This is a counterfeit product. (As we all know, the appearance of sparks is caused by impurities, and heterocopper contains high impurities, so it is not called a qualified explosion-proof tool).

6. Use of non-explosion-proof tools, accident cases

Qingdao "11.22" explosion: At 10:25 on November 22, 2013, the Donghuang oil pipeline of the pipeline storage and transportation branch of China ** Chemical Co., Ltd., located in Qingdao Economic and Technological Development Zone, Shandong Province, leaked crude oil into the municipal drainage culvert, and the oil and gas accumulation in the culvert forming a confined space exploded due to sparks, resulting in 62 deaths, 136 injuries and direct economic losses of 750 million yuan.

Analysis of the cause of the accident: After the crude oil leak, the on-site disposal personnel used a non-explosion-proof hydraulic breaker to punch holes and crush the culvert cover, resulting in impact sparks, causing an oil and gas explosion in the culvert, resulting in an explosion accident.

Explosion of Shandong ** Chemical Co., Ltd.: At 9:47 on March 18, 2015, an explosion occurred in the hydrogenation tower of the hydrogen peroxide unit of Shandong ** Chemical Co., Ltd., located in Zhanhua District, Binzhou City, resulting in 4 deaths, 2 injuries and direct economic losses of 4.882 million yuan.

Analysis of the cause of the accident: the operator carries a non-explosion-proof steel sleeve wrench and a steel tape measure into the tower, and there is a possibility of impact, friction and ignition during use, which may cause hydrogen explosion. The use of non-explosion-proof electrical appliances is also one of the possible sources of ignition. Operators carry non-explosion-proof flashlights and mobile phones into the tower, and there is a possibility of hydrogen explosion caused by ignition during use. Factors that caused the explosion, such as open flames, lightning strikes, and arson, were ruled out in the accident investigation.

7. How to extend the service life of explosion-proof tools

Proper maintenance of the hammer after we have used it plays a key role in the life of the tool:

(1) Usually store the explosion-proof hammer in a dry place.

(2) In our daily work, after 20 consecutive knocks, the surface attachments of the hammered explosion-proof hammer need to be treated in time, and then used after cleaning, and never used continuously, so as not to heat the tool because of the long-term percussion friction.

(3) After use, the explosion-proof hammer should be cleaned of surface dirt and accumulation, and then placed in a dry place for preservation.

(4) Percussion tool products such as explosion-proof copper hammers, percussion wrenches, etc., can not be continuously struck, more than ten times should have an appropriate intermittent, and at the same time, the product parts should be removed in time after the debris adhered to continue to use, if the surface of the hammering tool contains other metal hard particles, it is possible to cause sparks and explosion accidents when hammering again.

(5) The cutting edge tool should be placed in the sink and gently touch the grinding wheel for sharpening, and should not be used too hard and contact the grinding wheel for too long.

(6) Before using various products, the surface oil stain should be removed, and the explosion-proof hammer should be used correctly according to the instructions.