Classification standards for solenoid valve explosion-proof levels. How many levels of solenoid valve explosion-proof levels are there?

The solenoid valve explosion-proof grade classification standard meets the following three conditions and must use the corresponding explosion-proof solenoid valve explosion-proof grade: 1. Explosive substances: substances that can react with oxygen (air), including gases, liquids and solids;2. Gases: Gas, coal gas, liquefied petroleum gas, hydrogen, acetylene, methane, etc.;Liquid: alcohol, gasoline, diesel, petroleum, etc.;Solid: dust, fiber dust, etc.;3. Ignition source: including open flame, electrical spark, mechanical spark, electrostatic spark , high temperature, chemical reaction, light energy, etc.;my country's solenoid valve explosion-proof level standard is "GB3836.1-2000 Electrical Equipment for Explosive (Explosive) Gas Environments", which will be supplemented or modified by the following special standards for explosion-proof types. GB 3836.2 Electrical equipment for explosive (explosive) gas environments - Part 2: Flameproof type "d" GB 3836.3 Electrical equipment for explosive (explosive) gas environments - Part 3: Increased safety type "e" GB 3836.4 Explosion (explosive) Electrical equipment for explosive gas environments - Part 4: Intrinsically safe type "i" GB 3836.5 Electrical equipment for explosive (explosive) gas environments - Part 5: Positive pressure type "p" GB 3836.6 Electrical equipment for explosive (explosive) gas environments Part 6: Oil-filled type "O" GB 3836.7 Electrical equipment for explosive (explosive) gas environments Part 7: Sand-filled type "q" GB 3836.9 Electrical equipment for explosive (explosive) gas environments Part 9: Sealed type The explosion-proof grade standards for solenoid valves above "m" are not applicable to medical electrical equipment, detonators, detonator testers and ignition circuit testers. Common symbols are "ExmbⅠ/ⅡT4", "ExdⅠ/ⅡBT4", "ExdⅡCT5" "Ex" is a universal symbol, which means explosive. "d" means the secondary explosion-proof type is "explosion-proof type d". "Ⅰ" or "Ⅱ" means Classification of electrical equipment, I is electrical equipment for coal mines, II is equipment for other explosive (explosive) gas environments except coal mines. Among them, Class II explosion-proof "d" and intrinsically safe "i" electrical equipment are divided into IIA ,ⅡB and ⅡC categories. "T4" indicates the temperature group. There are several levels of explosion-proof level for solenoid valves. Europe and the United States have extremely strict explosion-proof level standards. The standard explosion-proof level is divided into nine categories, including explosion-proof type, increased safety type, intrinsic safety type, positive pressure type, oil-filled type, sand-filled type, and non-sparking type. Type, cast type, air-tight type to air-tightness, solenoid valves have very in-depth applications in gas, petrochemical, metallurgy, mining, medical and other industries. 1. Flameproof type d isolates existing ignition sources Zone1, Zone22, increased safety type e tries to prevent the generation of ignition sources Zone1, Zone23, intrinsically safe type ia limits the energy of ignition sources Zone0-2 Intrinsically safe type ib limits the energy of ignition sources Zone1 , Zone24, positive pressure type p Hazardous substances are separated from ignition sources Zone1, Zone25, oil-filled type o Hazardous substances are separated from ignition sources Zone1, Zone26, sand-filled type q Hazardous substances are separated from ignition sources Zone1, Zone27, non-sparking type n Try to prevent the ignition source Zone28, sealed type m Try to prevent the ignition source Zone1, Zone29, airtight type h Try to prevent the ignition source Zone1, Zone2 Explosion-proof solenoid valve grade description: ia grade: in normal operation, one fault and two Electrical equipment that cannot ignite explosive gas mixtures when a fault occurs. During normal operation, the safety factor is 2.0;when one fault occurs, the safety factor is 1.5;when two faults occur, the safety factor is 1.0. Note: Contacts with sparks must be installed with flameproof shell, airtight shell or