|[Electronic and Electrical] - [Electrical conduit]|
Explosion-proof tube BNG-DN70 * 1000 | Explosion-proof tube | explosion-proof hose | flexible |
Proof flexible connecting pipe is composed of a union joint and a connecting pipe; the connecting pipe is composed of an inner pipe and a sheath;
Live joints made of stainless steel, or high-quality carbon steel electroplating treatment;
The inner tube is made of bellows or metal hose, with good corrosion resistance;
With flame retardant, corrosion resistance, water resistance, aging resistance, good flexibility, solid structure, reliable and so on;
Thread size specifications can be customized according to user requirements, such as NPT Thread, inch and metric threads;
Explosion-proof flexible connecting pipe length, the conventional supplier 500mm , 700mm , 1000mm To choose from, but also according to user needs to customize the other length;
Please refer to the DN20 (G3 / 4 inch) metal pipe with M20 * 1.5 / 1 / 2NPT and so on. Please refer to the following specifications: DN20 (G3 / 4 inch) metal pipe with M20 * 1.5 / 1 / 2NPT and so on. Connection method!
First, the classification of explosive substances
According to the use of the environment can be divided into three categories:
Class I: mine downhole;
Class II: explosive gas mixture (including steam, mist);
Class III: explosive dust (including fiber or floc).
North American countries are different, also divided into three categories:
Class I: Explosive gases;
Class II: explosive dust;
Class III: explosive fibers.
Second, the explosion-proof grade grading group Representative gas Maximum test safety clearance Minimum ignition current
I methane - mine
IIA ethane, propane, carbon monoxide, methanol, gasoline propane> 0.9m m> 0.8
Ⅱ B gas, ethylene ethylene 0. 5 ~ 0.9 m m 0.45 ~ 0.8
IIC hydrogen, acetylene hydrogen acetylene< 0.5m m < 0.45
The equipment marked with IIB can be used for the use conditions of IIA, and the equipment of the mark IIC can be used for the use conditions of IIA, IIB equipment.
Third, the temperature of the gas or steam explosive gas mixture
Divided into 6 groups, the maximum surface temperature of the device is not allowed to exceed this value minus the temperature value of 5 ℃.
T1 - 450 ℃, T2 - 300 ℃, T3--200 ℃
T4--135 ° C, T5--100 ° C, T6 - 85 ° C
Fourth, according to the explosion-proof form of classification
1. Explosion-proof explosion-proof equipment 'd', originally built by the German explosion-proof form. Currently the world's most mainstream application of explosion-proof form.
2. Increased safety explosion-proof equipment 'e', the use of high cost, a small amount of use
3. Intrinsically safe explosion-proof equipment 'i', the use of high cost, a small amount of use
4. Positive pressure explosion-proof equipment 'p', the use of high cost, rarely used
5. Casting explosion-proof equipment 'm', maintenance inconvenience, a small amount of use
6. Airtight explosion-proof equipment 'h', maintenance inconvenience, a small amount of use
7. No spark-type explosion-proof equipment 'n', high manufacturing costs, rarely used
8. Oil-filled explosion-proof equipment 'o', rarely used
9. Sand-type explosion-proof equipment 'q', rarely used
Fifth, the definition of dangerous places
Depending on the material state of the substance in the site, the hazardous area is divided into an explosive gas atmosphere and a flammable dust environment.
According to the length of the dangerous material in the place, the two different types of dangerous places are divided into three areas, namely: the explosive gas environment, 0, 1 and 2; for flammable dust environment, 20 districts, 21 districts and 22 districts.
(1) Explosive gas environment GB 3836.14-2000 standard provides:
Zone 0: Explosive gas environment where there is a continuous or prolonged existence.
Zone 1: In the normal operation, there may be explosive gas environment of the place.
Zone 2: During normal operation, there is no possibility of an explosive gas environment, and if it occurs, it is occasionally occurring and is only a short time.
'Normal operation' refers to the normal driving, operation, parking, loading and unloading of flammable substances, opening and closing of sealed container caps, safety valves, discharge valves and all plant equipment in the design parameters within the scope of its work.
(2) flammable dust environment GB 12476.1-2000 standard provides:
Zone 20: Flammable dusts are present or frequent during normal operation in quantities sufficient to form a mixture of flammable dust and air and / or may form sites and containments of uncontrollable and extremely thick dust layers.
Zone 21: During normal operation, there may be sites where the amount of dust is sufficient to form a mixture of flammable dust and air but not in zone 20. This area includes areas directly adjacent to the point of filling or discharging dust, Areas where flammable dust and air mixture of flammable concentrations may occur under normal operating conditions.
Zone 22: Areas where flammable dust clouds are present occasionally and are present only occasionally, or where flammable dusts occasionally accumulate or may present dust layers and produce flammable dust air mixtures under abnormal conditions. Or dust layer, it should be divided into 21 areas.