Concrete Nails
We offer complete types of concrete nails covering galvanized concrete nails, color concrete nails, black concrete nails, bluish concrete nails and concrete nails with various special nail heads and shank types. Common diameter sizes for galvanized concrete nails are 1.7~5.0mm and the nail length goes from 16mm to 50mm.
Concrete Nails,Polished Concrete Nails,Galvanized Concrete Nails,Black Boiling Concrete Nails HENGSHUI YUZHENG IMPORT AND EXPORT CO., LTD. , https://www.yzironnails.com
The first part is series code M, the first prefix of the pinyin of coal.
The second part is the use of characteristic code, reflecting the occasions used by the cable. The meanings of the letters are as follows: C, for coal mining machine; D, for low-temperature environment; M, cap lamp; Y, for coal mining equipment (moving); Z, for electric drilling.
The third part is the structural feature code, indicating the structural characteristics of the cable. The meanings of the letters are as follows: B, weaving strengthening; J, with monitoring core; P, non-metallic shielding; PT, metal shielding; Q, lightweight;
The fourth part is the material feature code, E is used to indicate that the insulation or sheath is made of elastomer material. This part is omitted when rubber and insulation are used. E, elastomer material.
The fifth part is rated voltage U0/U(KV).
The sixth part is the representation of the number of power cores * nominal cross-sectional area. The two are connected by a multiplication sign and the unit is square millimeters.
The seventh part is the representation of the number of ground cores* nominal cross-sectional area. The two are connected by a multiplication sign and the unit is square millimeters.
The eighth part is the representation of the number of auxiliary cores * nominal cross-sectional area. The two are connected by a multiplication sign and the unit is square millimeters.
The fourth part and the fifth part are connected with "-"; the sixth part, the seventh part and the eighth part are connected with "+".
Mine cable fire performance analysis and engineering application As the increase of wire and cable, the concentration of laying, the poor quality of construction, etc., exacerbated the risk of wire and cable fire. Therefore, to prevent wire and cable fires in practical engineering applications, it is necessary to start with the control of risk factors and apply relevant regulations to take corresponding fire prevention measures.
A wire and cable and the cause of the fire is mainly because the characteristics <br> <br> overload, short circuit, excessive contact resistance and external heat sources. Short circuit, local overheating and other fault conditions and external heat, wire and cable cause fire causes. Insulation data reduces insulation resistance, loses insulation, and even burns, causing fire. The main characteristics of the wire and cable during a fire are as follows: In the case of a fire, the fire temperature is generally 800°C to 1000°C. The wire and cable will soon lose their insulation ability, which will cause secondary electrical accidents such as short circuit, which will cause greater losses; 2 The wire cable will have greater overload capacity under the specified allowable ampacity; the wire and cable will cause insulation data to melt in an instant , combustion, 3 short circuit conditions. And ignite the surrounding combustibles.
2 wire and cable fire performance analysis
2.1 Analysis of Fire Protection Mechanisms 2.1.1 The flame retardant mechanism is based on the decomposition of the flame retardant in the condensed phase and the heat of the combustion reaction. Slowing down the temperature rise in the condensed phase, delaying the thermal decomposition rate of the data; releasing a chain reaction radical blocking agent, 2 after the flame retardant is decomposed by heat. The flame and chain reaction branches are interrupted and the gas phase reaction rate is slowed. The formation of a coking layer or a foam layer enhances the effect of these layered hard shells on blocking the heat transfer. 3 The catalytic coacervation phase thermally decomposes the solid phase products. The flame retardant undergoes an endothermic phase transition, under the influence of 4 heat. Physically prevents the temperature in the condensed phase from rising.
2.1.2 Fire resistance mechanism Reduce the amount of heat generated by the polymer. Add an additive to the wire and cable insulation and sheathing data. Prevents the decomposition of polymers or promotes the insulation of the insulation and sheathing material to form a maintenance layer; after insulation and sheathing layers are ignited by fire, an inorganic insulating material such as mica glass ribbon is added at the 2nd core. * The mica fireproof belt wrapped around the conductor is maintained and continues to be energized so as to maintain normal operation for a certain period of time during a fire.
2.1.3 Mechanism of Mineral Insulated Cables AlOH3 is 34.6% under high temperature operation. The absorption effect of metal hydrate makes the cable flame retardant. For example: AlOH3 and MgOH as flame retardants. The MgOHz is 31%, and the reactions shown in Reaction Formula 1 and Reaction 2 are decomposed into endothermic reactions, so that the combustion of the high polymer can be suppressed. 2AIOH3--*Alz03+3H20-2648KJ1MgOH2--MgO+H20-93.3KJ2
A lot of users do not know how to judge the quality of cables when they choose cables! Again, I will explain to you, "How to distinguish the cable is not the national standard line", "How to buy wire and cable? "These two points, this is also the user must buy the cable" must learn knowledge", I hope to help you!
1. Distinguish between the cable is not a way to check if the wire and cable required by the national standard line is a few aspects of the mark:
1, look. See if there is a quality system certification; see whether the certificate is standardized; see if there is a factory name, site, inspection seal, production date; see if the trademark is printed on the wire, specifications, voltage, etc. Also look at the cross section of the wire copper core, superior product copper color bright, soft color, otherwise it is defective.
2, to try. It is advisable that a wire head be repeatedly bent by hand, and that any product that has soft hand feeling, good fatigue resistance, plastic or rubber feel elasticity, and no crack on the wire insulation body is superior.
3, weigh. Good quality wires are generally within the specified weight range. Such as the commonly used cross-sectional area of ​​1.5mm2 plastic insulated single strand copper wire, each 100m weight of 1.8 ~ 1.9kg; 2.5mm2 plastic insulated single strand copper wire, weight per 100m 3 ~ 3.1kg; 4.0mm2 plastic Insulated single-stranded copper wire weight is 4.4-4.6kg per 100m. Poor quality wires have insufficient weight or are either of insufficient length or have too many impurities in the wire copper core.
4, than the price. Because of the low cost of making fake and shoddy wires, when selling, traders often sell at a low price for good value, which makes people fooled.
5, see the copper. Qualified copper core wire copper core should be purple, shiny and soft to the touch. The shoddy copper core copper core is purple-black, yellowish or white, with many impurities, poor mechanical strength, and poor toughness. It will break when it is hardened, and the wire is often broken. During the inspection, you just peel off the wire by 2cm, and then use a white paper to slightly squat on the copper core. If there is black material on the white paper, there is more impurities in the copper core. Tianjin Cable Plant Rubber Cable Factory 15175658435
2. How to choose wire and cable?
Wire and cable products have a close relationship with the lives of consumers. Its quality and safety have a direct impact on the safety of people and property of consumers. Therefore, it is very important to purchase wires and cables correctly. Xingchengyi Cable Co., Ltd. reminds you that when you purchase wires and cables, authentication is the key. The method of identification is as follows:
1, look at the "CCC" certification mark. Wire and cable products are national compulsory safety certification products. All production companies must obtain the “CCC†certification from the China Electrotechnical Products Certification Committee, and have “CCC†certification marks on the certificates of conformity or products.
2, see the inspection report. Wire and cable, as a product that affects personal and property safety, has long been listed as the focus of government supervision and inspection, and regular manufacturers are inspected by the supervisory department on a periodic basis. Therefore, the seller should be able to provide the inspection report of the quality inspection department, otherwise, the quality of the wire and cable products is lack of evidence.
3, see the packaging. All the regular enterprises that produce products in line with the national standards, the production of wire and cable pays attention to product packaging. Pay attention to the exquisite packaging, the printing should be clear, the model specifications, the name of the factory, and the complete site.
4, look outside. Product appearance smooth and round, uniform color. The wire and cable companies whose products meet the requirements of the national standards must strictly control the purchase of raw materials, production equipment, and production processes in order to improve product quality and ensure that the products meet the requirements of the national standards. Therefore, the appearance of wire and cable products produced meets the requirements of the standard, smooth and round, uniform color. The appearance of fake and shoddy products is rough and dull. For the rubber-insulated flexible cable, the appearance is required to be round and the sheath, insulation, and conductor are not easily peeled off. The appearance of counterfeit and shoddy products is rough, the ellipticity is large, and the insulation strength of the sheath is low, and it can be torn by hand.
5, see the conductor. The conductor is shiny, and the DC resistance and conductor structure dimensions meet the requirements of national standards. The wire and cable products that meet the requirements of national standards, whether aluminum conductors or copper conductors, are all brighter and free from oil pollution. Therefore, the DC resistance of conductors is in full compliance with national standards, with good electrical conductivity and high safety.
6, the amount of wire and cable length. The length is the main intuitive method of distinguishing between compliance with national standards and counterfeit and shoddy products. Do not try to buy cheap, cheap, buy the actual number of meters below its nominal number of wire and cable. The length must match the nominal number of meters. The national regulations allow an error of ±0.5 meters per 100 meters.
After the explanation is finished, when you purchase the cable later, referring to the above method, you can purchase the qualified cable. You can rest assured that it is our biggest achievement in sales!
What causes the cable to explode?
What caused the explosion of the cable?
The insulation layer of the power cable is composed of various combustible materials such as paper, oil, hemp, rubber, plastic, and asphalt. Therefore, the cable has the possibility of fire and explosion. The cause of the cable explosion is:
(1) Insulation damage causes a short-circuit fault.
(2) The cable is overloaded for a long time.
(3) The oil-immersed cable is damaged or leaks due to height difference. When the height difference of the oil-immersed cable laying is large (4) The insulation of the middle joint box breaks down.
(5) The cable end burns.
(6) External fire and heat sources cause cable fires.
First, the cable's name consists of eight parts: