The classification core of PVC conduit revolves around mechanical properties, structural forms, temperature adaptability, and functional requirements. Combined with the new national standard specifications, different categories of products have significant differences in compressive, cold resistant, and flame retardant properties, and need to be accurately matched according to wiring scenarios and environmental conditions to avoid safety hazards.
According to mechanical properties, it can be divided into three categories: light, medium, and heavy. The new national standard clearly indicates the code: light (code 2) has thinner pipe walls and is suitable for low mechanical stress environments. It is mostly used for exposed wiring in ceilings and walls, and is suitable for scenarios without external impact; Medium sized (code 3) pipes have moderate wall thickness and balanced strength, making them the preferred choice for home decoration, water and electricity renovation, and ordinary office building wiring. They are suitable for conventional wiring of strong and weak electricity; The heavy-duty (code 4) pipe has the thickest wall and outstanding compressive and impact resistance. It is suitable for scenarios with strong loads such as ground buried pipes, concrete embedment, and industrial sites, and can effectively resist external damage during construction and use.
According to its structural form, it can be divided into solid wall sleeves and corrugated sleeves: solid wall sleeves are the mainstream style, with smooth inner and outer surfaces, low threading resistance, stable mechanical performance, suitable for the vast majority of strong and weak electrical wiring scenarios, and easy installation; The outer wall of the corrugated sleeve has a wavy shape, good flexibility, and can be manually bent into shape without the need for additional bends. It is suitable for weak current lines (network cables, telephone lines) and complex space wiring, but has weak compressive performance and is not suitable for ground embedding and mechanical load scenarios. It is divided into single wall and double wall types, with double wall corrugated pipes having better impact resistance.
According to the temperature adaptation level, it can be divided into five categories: -25 type can withstand low temperatures of -25 ℃ without cracking, suitable for cold northern regions or outdoor construction in winter; -Type 15 is suitable for indoor and outdoor construction in most regions of the country; -Type 5 is suitable for general climate conditions such as southern regions or interior buildings; The 90 type continuous temperature resistance can reach 90 ℃, suitable for areas with concentrated heat such as equipment rooms and pipe wells; The 90/-25 type has both high and low temperature resistance, with the strongest environmental adaptability, suitable for construction areas with alternating cold and hot temperatures.
According to their functions, they can be divided into ordinary insulation type, flame retardant type, anti-corrosion type, and high insulation type. Flame retardant type with added flame retardants is essential for high-rise buildings and places with strict fire protection requirements, as it does not burn or spread when exposed to fire; Anti corrosion type with added UV resistant agents and acid alkali resistant auxiliary materials, suitable for outdoor, chemical plant and other corrosive environments; The high insulation type pipe wall is thickened to 2.5mm or more, used for high-voltage cable protection and improving electrical safety. According to the nominal diameter (DN), it can be divided into small diameters (DN10, DN15, DN20, suitable for weak current), medium diameters (DN25, DN32, suitable for lighting and ordinary socket lines), and large diameters (DN40, DN50, DN63, suitable for main power supply lines).