Applicable Industry Standard: SY/T 0447‑2014 Technical Standard for Epoxy Coal‑tar Anticorrosive Coating of Buried Steel PipelinesThe whole process consists of five stages: Factory Pre‑fabrication of Anticorrosive Coating → Hoisting & Welding of Pipes → Field Joint Coating & Repair of Damages → Pipe Lowering and Backfilling in Trench → Completion Acceptance Construction Environmental Requirements Construction temperature: 5‑40℃; Low‑temperature curing coating shall be adopted when ambient temperature is below 5℃. Air humidity: Relative humidity ≤ 85%; The steel pipe surface temperature shall be 3℃ higher than the dew‑point temperature. Open‑air anticorrosion work is forbidden in rainy, snowy, foggy weather or when wind force reaches Grade 5 or above. Procedures for Factory […]

The anti-corrosion system complies with SY/T 0447-2014 Specification for Epoxy Coal Tar Anti-Corrosive Coating of Buried Steel Pipelines. Classification is mainly based on anti-corrosion structural grade, together with other grouping methods as below. Classified by Anti-Corrosion Structure (Most Widely Adopted in Engineering) Ordinary Grade: One Coat & One Cloth Structure: 1 primer coat + 1 topcoat + 1 layer of glass fiber cloth + 1 topcoatMinimum total dry film thickness: 0.3 mmApplication: Dry soil with mild corrosion, temporary pipelines, drainage branch pipelines Reinforced Grade: Three Coats & Two Cloths (Market Mainstream) Structure: Primer → Topcoat → Glass Fiber Cloth → Topcoat → Glass Fiber Cloth → TopcoatMinimum total dry film […]

ASTM A795 is a dedicated carbon steel pipe standard for the North American fire protection industry, specially formulated for building automatic fire suppression systems. It covers both welded and seamless pipes. Unlike general-purpose fluid galvanized pipes, all performance, process and testing requirements of this standard are formulated for the core working conditions of fire protection systems, including long-term static service, instantaneous pressure bearing and anti-rust blockage performance. The pipe specifications range from NPS 1/2 to NPS 10 (DN15–DN250), with mainstream wall thicknesses of Sch10 light-duty thin-wall and Sch40 standard pressure wall. It includes two steel grades, Grade A and Grade B. Grade B is widely adopted in building fire protection […]

On-site welding construction of hot-dip galvanized steel pipes, It focuses on controlling zero weld defects, qualified structural strength and complete post-welding anti-corrosion performance, so as to eliminate quality problems such as pores and cracks caused by zinc layer vaporization. Pre-welding Preparation Requirements Pipe Inspection: Check the specifications, wall thickness and material of galvanized pipes before construction to ensure compliance with design requirements. The pipes shall be free from deformation, damage and severe corrosion with uniform and intact galvanized layers. Unqualified pipes are prohibited from welding. Groove Machining: For pipes with wall thickness ≥ 3mm, V-shaped grooves are required with a groove angle of 55°-65° and a root face of 1-1.5mm. […]

Polyurethane paint is a mainstream topcoat system for steel pipe anti-corrosion coating due to its excellent weather resistance, chemical corrosion resistance, high adhesion and mechanical properties. Its selection must strictly follow the core principles of “environment adaptation, performance matching, system compatibility, and construction feasibility”, and combine with the steel pipe’s service environment, corrosion level, operating conditions and construction conditions to select scientifically to ensure anti-corrosion life and structural safety. The core premise of selection is to clarify the service environment and exposure state of the steel pipe: For outdoor overhead, exposed municipal pipe networks, and steel pipes in coastal and chemical industrial areas that are long-term exposed to ultraviolet radiation, […]