On‑site welding is strictly forbidden. High temperature will damage inner and outer plastic coating and cause anti‑corrosion failure. Grooved connection, flange connection and threaded connection are recommended. Only metal saw is allowed for cutting; abrasive wheel cutting is prohibited. After cutting, remove burrs and grind round corners with file, and repair damaged areas with epoxy coating. Throwing, dropping and heavy impact are forbidden during transportation, loading‑unloading and construction to prevent coating peeling. Cold bending is permitted for pipes DN50 and below. Bending radius shall not be less than 8 times pipe diameter and bending angle shall not exceed 10°. Hot bending is not allowed. Do not embed pipes directly into reinforced concrete structure layers.

Plastic‑coated steel pipes combine high mechanical strength of steel and excellent anti‑corrosion & insulation performance of plastic coating. Smooth inner wall brings low friction coefficient, less flow resistance and anti‑scaling performance. Excellent insulation enables effective signal shielding for cable protection and prevents galvanic corrosion & electric leakage. Low water absorption resists soil stress and damage from plant roots. Light weight enables easy connection and maintenance with long service life. Resistant to humidity, high and low temperature, it is an upgraded alternative for traditional galvanized pipes and plastic pipes.

Galvanized steel pipes rely on zinc layer for corrosion protection. When buried or exposed to water, the zinc layer is prone to rust. After several years of service, inner wall will scale and corrode, causing secondary water pollution. Plastic‑coated steel pipes are fully lined with PE or epoxy resin coating both inside and outside, isolating steel substrate from water and soil, delivering much longer anti‑corrosion service life. Its smooth inner wall resists scaling with superior insulation performance. However, on‑site welding is not permitted; grooved, flange or threaded connections shall be adopted. Plastic‑coated steel pipes are preferred for municipal water supply‑drainage, fire‑fighting and buried projects.