4 Inch Galvanized Steel Pipe

Specifications

Product Name	4 Inch Galvanized Pipe
Nominal Diameter (DN)	DN100
Imperial Standard	4 inches
Actual Outer Diameter	Approximately 114mm (standard value 114.3mm)
Common Wall Thickness Range	2.5mm – 4.0mm (common thicknesses: 2.75mm, 3.0mm, 3.2mm, 3.5mm, 3.8mm, 4.0mm)
Standard Single Length	6 meters (standard); 3 meters, 9 meters, 12 meters, etc., custom lengths available upon request
Base Steel Grade	Q195, Q235B, Q345B, etc.
Standard Applicable	GB/T 3091-2025, ASTM A53, BS 1387/1967
Galvanizing Process	Hot-dip galvanized (fully galvanized inside and out)
Connection Method	Threaded connection, grooved connection, flange connection, welding
End Treatment	Flat end, chamfered, threaded (optional)
MOQ	5 tons
Packaging	Standard export packaging or as per customer requirements

Wall Thickness Selection Reference Table

Wall Thickness Range	Recommended Applications
2.5mm – 3.0mm	General water supply, low-pressure fire-fighting branch pipes, indoor water supply
3.0mm – 3.5mm	Low-pressure gas transmission, HVAC piping, irrigation mains
3.5mm – 4.0mm	Structural support (factory frame, guardrail posts), outdoor pressure-bearing pipelines
≥4.0mm	High-pressure conditions, buried main pipelines, heavy-duty structures

Note: When the wall thickness exceeds 3.5 mm, the increase in pressure-bearing capacity per unit of thickness gradually decreases; therefore, a comprehensive cost-benefit analysis should be conducted when selecting a model.

Weight of 4-inch Galvanized Pipe

Weight Calculation Formula

The weight of galvanized steel pipe is calculated in two steps: first, calculate the weight of the base pipe (black pipe), then calculate the weight after galvanizing.

Theoretical weight of base pipe = 0.0246615 × (D − t) × t

Where:

• D = Outer diameter of steel pipe (mm); for 4-inch pipe, use 114.3 mm
• t = Nominal wall thickness (mm)
• 0.0246615 = Conversion factor based on steel density of 7.85 g/cm³

Theoretical weight per meter after galvanizing (kg/m) = Theoretical weight of base pipe × c

Where c is the galvanized coating weight coefficient, which depends on the wall thickness:

• For a wall thickness of 2.5 mm, c ≈ 1.051
• For a wall thickness of 3.0 mm, c ≈ 1.040
• For a wall thickness of 3.5 mm, c ≈ 1.036
• For a wall thickness of 4.0 mm, c ≈ 1.032
• For a wall thickness of 4.5 mm, c ≈ 1.028

Theoretical weight per meter of 4-inch galvanized steel pipe

Wall thickness (mm)	Weight of black tube (kg/m)	Weight after galvanizing (kg/m)
3	(114.3-3)×3×0.02466 ≈ 8.24	Approximately8.50
3.2	(114.3-3.2)×3.2×0.02466 ≈ 8.77	Approximately9.05
3.5	(114.3-3.5)×3.5×0.02466 ≈ 9.57	Approximately9.88
3.8	(114.3-3.8)×3.8×0.02466 ≈ 10.36	Approximately10.68
4	(114.3-4)×4×0.02466 ≈ 10.88	Approximately11.22
4.5	(114.3-4.5)×4.5×0.02466 ≈ 12.20	Approximately12.57

Advantages of 4-Inch Galvanized Steel Pipe

• Precise Dimensions: 4 inches corresponds to DN100, with an outer diameter of 114.3 mm, making it internationally compatible. It offers high dimensional compatibility for both domestic engineering projects and export projects.
• Stable Pressure Resistance: Manufactured using high-quality base pipes, it features outstanding resistance to pressure, bending, and impact; wall thickness can be flexibly selected to meet different pressure requirements, balancing safety and cost-effectiveness.
• Corrosion Resistance and Durability: Both inner and outer walls are hot-dip galvanized, with the zinc coating metallurgically bonded to the steel substrate to prevent peeling. This effectively blocks corrosion from air, moisture, and acidic or alkaline substances, ensuring a long service life.
• Easy to Process, Efficient Installation: The pipe can be easily cut, welded, cold-bent, and threaded, enabling high on-site construction efficiency. The standard 6-meter length design balances transportation convenience with on-site splicing requirements.

Applications of 4-Inch Galvanized Steel Pipe

• Building Plumbing and Fire Protection: Hot and cold water main lines in high-rise residential buildings, office towers, and hotels; automatic sprinkler systems and fire hydrant networks (4-inch pipes are a common specification for fire protection loop networks).
• Industrial Applications: Central air conditioning cooling water pipes, heating hot water main lines, and equipment cooling water networks; can also be used as mine ventilation ducts and electrical conduit.
• Municipal and Industrial Fluid Conveyance: Outlet mains for water treatment plants, distribution pipelines for wastewater treatment plants; low-pressure gas transmission (wall thickness ≥3.5 mm), chemical medium transmission (medium compatibility must be confirmed).
• Structural Support and Guardrails: Diagonal braces and columns for steel structural frames in industrial plants; highway guardrail posts, temporary bridge supports, and construction scaffolding; outdoor guardrails, fences, and flagpoles.
• Agriculture and landscaping: Greenhouse frames, water supply pipelines for large-scale livestock farms, and main irrigation canals for farmland.

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Why Choose Us

We offer a comprehensive range of galvanized steel pipe sizes and specifications, and can supply galvanized steel pipes in various materials and in compliance with national standards. We have obtained multiple certifications, including ISO 9001, ISO 14001, and ISO 45001. With over 15 years of extensive experience, we have successfully exported our products to more than 120 countries. If you have any procurement needs for galvanized steel pipes, please feel free to contact us at any time.