What is explosion?

The prerequisite for triggering an explosion is that the explosive material must be mixed with oxygen to a certain extent to cause a chemical reaction under appropriate ignition conditions. If the speed of reaction exceeds the speed of sound, it is defined as an explosion

• The explosive mixture that accumulates to a certain degree explodes suddenly and causes destruction effect in the form of explosion wave.

• What is explosion proof? :

  An explosion can be prevented if any one of the above three conditions is restricted. At many service sites, the presence of explosive substances and oxygen is difficult to avoid, so the source of ignition must be limited. Electrical equipment is a potential source of ignition. When the machine is running, it causes surface temperature rise, electrostatic release or sparks caused by instantaneous current.

• The explosion-proof electrical equipment is designed to avoid excessive surface temperature and spark during its operation. Therefore, explosion-proof electrical equipment will not become a potential source of ignition.

• Classification of potentially explosive environments :

  Generally, electrical equipment used in explosive gas environments can be divided into two categories

  Class I Electrical equipment for coal mine

  Class II Electrical equipment for explosive gas environments other than coal mine

• For Class II electrical equipment, explosive gas can be divided into three explosive levels: IIA,IIB and IIC according to the maximum test safety gap (flameproof type) and minimum test ignition current (intramentally safe type). Class IIB equipment can be applied to the service conditions of IIA equipment, and class IIC equipment can be applied to the service conditions of IIA and IIB equipment.

  For Class II electrical equipment, according to the maximum allowable surface temperature can be divided into T1 (450 ° C), T2 (300 ° C), T4(135 ° C), T5(100 ° C), T6 (85 ° C) six temperature groups, and the high temperature group equipment can be applied to the use of low group conditions.

  More than 90% of the explosive gases are contained in the IIA, IIB explosive levels and T1-T4 temperature groups.

• How to achieve explosion-proof? :

  There are various ways to make electrical equipment suitable for explosive environments, and these methods are described in detail in GB3836,ICE60079, EN50014 and other standards.

  PVQ series explosion-proof electric actuators are manufactured in accordance with the explosion-proof type of "flameproof type "(Exd), in line with GB3836.1-2010, GB3836.2-2010 standard requirements.

• Explosive Level :

  The flameproof actuators allow explosions to occur inside the equipment. The flameproof surface of the housing is designed to prevent the internal spark or explosion carrier from contacting the outside world. Appropriate flameproof surface clearance and sufficient length of the flameproof surface ensure this. At the same time, the sturdy shell can withstand the high pressure generated by the internal explosion without being damaged

  The following parts of PVQ series actuators are designed and manufactured according to flameproof standards.
  Motor chamber     Electrical element chamber     Wiring chamber

• Explosion-proof Grade :

  AUQ explosion-proof series electric actuator grade: ExdIICT6Gb

  Ex-Explosion-proof marking

  D-Explosion-proof type: flameproof

  II-Equipment type: other gas environments except coal mine

  C-Explosive level, this level determines the size (length and clearance) of each flameproof joint of the actuator.

  T6-Temperature class,the maximum allowable surface temperature of the actuator is 85° C

  Gb-Explosion protection level of equipment

• How to use and maintain explosion-proof electrical equipment? :

  Installation, commissioning, maintenance, repair, and replacement shall be carried out by qualified explosion-proof professionals who have been trained, and shall strictly comply with the requirements of the electrical equipment (operation manual).