Size:Outside diameter:
Round pipe: 17mm-273mm
Square pipe:15mm x 15mm - 400mm x 400mm
Rectangular pipe: 10mm x 20mm -200mm x 400mm
Wall thickness:
Round pipe: 0.6mm-12mm
Square pipe:0.6mm-20mmRectangular pipe: 0.6mm-20mm
Length:2m-5.8m/6m/12m (We can adjust length according to
your request)
Standard
GB/T 3091 Q195/Q215/Q235/Q345, BS 1387,EN 39,EN 1139
S235JR/S275JR, ASTM A53 GR. A/B/C, JIS G3444 STK
400/STK500
Pipe type:Seamless & Welded Steel Pipe
(Round/Square/Rectangular)
End:Square Cut/Threaded, Burr Removed
Zinc Coating: 120~500 g/m2 (30um~70um)
Packing:Steel Strips bundled, Plastic Caps plugged,
Waterproof Paper wrapped etc.

Execution Standard: GB/T3091-2025 Welded Steel Pipes for Low-Pressure Fluid Transportation
Application Scope: Mainly used for transporting flammable gases such as coal gas and natural gas, as well as other general pressure fluids.
Steel Grades: Q195, Q215, Q235, Q345, 10#, 20#, 35#

Galvanized steel fire sprinkler pipes, often referred to as GI (Galvanized Iron) fire pipes, are carbon steel pipes coated with a zinc layer to enhance corrosion resistance, designed specifically for fire protection systems like wet, dry, preaction, and deluge sprinkler systems. ASTM A795, a key standard for these pipes, specifies both black and hot-dip galvanized welded (ERW) and seamless steel pipes for fire fighting applications, available in Grades A and B, with Grade B being more common due to its mandatory post-weld heat treatment (minimum 1000°F or 540°C). The galvanization process involves dipping the steel pipe in molten zinc, creating a protective coating of at least 1.5 oz/ft² (0.46 kg/m²), which shields the pipe from rust in moist environments, per ASTM A795 requirements.

Galvanized square steel pipe is a welded steel pipe with a hot-dip galvanized or electro-galvanized layer on the surface. Galvanizing can increase the corrosion resistance of steel pipes and prolong the service life. Galvanized pipes are widely used. In addition to being used as pipeline pipes for general low-pressure fluids such as water, gas, and oil, they are also used as oil well pipes and oil pipes in the petroleum industry, especially in offshore oil fields, and oil heaters and condensers in chemical coking equipment. Pipes for coolers, coal distillation washing oil exchangers, and pipes for trestle piles and supporting frames of mine tunnels, etc.