Positive pressure type p
Safe electrical equipment protects the system from static positive pressure or maintains a continuous flow of air or inert gas by keeping the pressure of the protective gas inside the enclosure higher than the pressure of the surrounding explosion-proof environment to limit the flow of combustible mixtures into the enclosure. Take away the combustible gas that enters the housing when the equipment is not under positive pressure, to prevent the formation of combustible mixture in the housing.
The place I
All the internal circuits of the equipment are in accordance with the standard conditions (including normal operation and the specified fault conditions), any spark or any effect generated can not point to the essential safety circuit of the specified explosion-proof gas environment.
Encapsulation type m
Will probably have an explosive mix inclusion ignition spark, arc or dangerous temperature part of electrical components, encapsulation in encapsulation agents (compounds), so that it can't lit around the explosive mixture using encapsulation measures, can prevent the electrical components short circuit and curing electrical insulation, avoid the circuit of the ignition of spark and arc and dangerous temperature produce and prevent the invasion of the explosive mixture, control table surface temperature under normal and fault conditions.
Oil filling o
The whole equipment or parts of the equipment shall be impregnated with the protective liquid l in the oil, so as not to point the explosion-proof gas environment above the fuel level or outside the shell.
Sand mold filling q
Protective type of electrical equipment in which sand particles or other powder materials with specified characteristics are filled in the shell so that the arc generated in the shell or at high temperature cannot ignite the surrounding explosive gas environment under specified service conditions.
Airtight type h
The type of this kind of explosion-proof equipment is airtight shell. That is, the explosive mixture of gases in the environment cannot enter the inside of the device housing. The airtight case is sealed by means of melting, extrusion or gluing. Most of the cases are non-detachable to ensure tightness.