Surface Box Material Comparison

Surface boxes serve as critical protective components for pipeline system instruments, wiring, and valve connections, with material directly determining their durability, applicability, and service life. Plastic and cast iron are two mainstream surface box materials, differing significantly in performance, applicable scenarios, and cost.

I. Core Material Properties & Performance Differences

Plastic Surface Boxes

Common materials: Polypropylene (PP), polyethylene (PE), ABS engineering plastics, often reinforced with glass fiber to improve strength.

Key performance: Lightweight, easy to transport and install; excellent corrosion resistance, immune to acid, alkali, salt, and chemical medium erosion; good insulation, preventing signal interference and electric leakage risks; low friction coefficient, smooth surface, and not easy to adhere to dirt.

Limitations: Poor pressure and impact resistance lead to deformation or cracking under heavy vehicle stress or external impact. Low temperature resistance is average, with some plastics becoming brittle in environments below -20℃.

Cast Iron Surface Boxes

Common materials: Ductile iron, gray cast iron, with surface treated by hot-dip galvanizing or epoxy coating for corrosion protection.

Key performance: Ultra-high mechanical strength of cast iron surface boxes, strong pressure resistance, and impact resistance, so cast iron surface boxes are not easy to deform or damage; good high-temperature resistance of cast iron surface boxes, stable performance of cast iron surface boxes in high-temperature environments; long service life of cast iron surface boxes, generally up to 20–30 years.

Limitations: Heavy weight, requiring more labor for transportation and installation; poor corrosion resistance of the base material, must rely on surface anti-corrosion treatment—once the coating is damaged, it is easy to rust; poor insulation, easy to cause signal interference, and need additional insulation measures when used in electrical systems.

II. Applicable Scenario Differentiation

Plastic Surface Boxes

Ideal scenarios: Municipal water supply and drainage pipe networks, landscaping irrigation systems, indoor pipeline protection for instruments, chemical pipelines with high corrosivity, and low-traffic pedestrian areas.

Typical applications: Protecting pressure sensors, flow meter wiring, and small valve components in corrosive environments or areas with low loads.

Cast Iron Surface Boxes

Ideal scenarios: Heavy traffic areas, industrial factory areas, underground pipeline valve wells, high-pressure pipeline systems, and outdoor harsh environments with frequent mechanical impacts.

Typical applications: Protecting main pipeline valves, large instrument connections, and pipeline junction components in areas where heavy vehicles pass or are prone to external collisions.

In practical applications, it is also necessary to combine the protection level requirements of surface boxes and the environmental temperature range to further optimize the material selection of surface boxes.