1 Inch Galvanized Pipe

1 Inch Galvanised Pipe Specifications

Product Name	1 Inch Galvanized Pipes
Nominal Diameter	1 inch (DN25/33.7mm)
Common Wall Thickness	2.8mm, 3.0mm, 3.2mm
Length	6-meter standard length, custom lengths of 4 meters, 9 meters, etc. are also available
Common Materials	Q195-215, Q235B carbon structural steel, or S235JR, S275JR, S355JR, A35, A36
Surface Quality	Uniform and complete coating, smooth and burr-free, with no black spots or missed coatings.
Standards	GB,ASTM,JIS,EN
MOQ	5 tons
Packaging	Standard export packaging or as per customer requirements

Conversion Rules Between Inches and DN

Meaning of Corresponding Numbers

• The “1 inch” or “DN25” marked on galvanized pipes actually represents two distinct measurement systems: ‘inch’ denotes the imperial unit, while “DN” signifies the international standard for nominal diameter.
• Taking a 1-inch pipe as an example, its standard outer diameter is 33.7mm. This discrepancy stems from the allowance for pipe wall thickness—akin to a water pipe wearing an “invisible coat”—ensuring both flow capacity and pressure resistance.

Conversion Rules

• Basic Correspondence: 1 inch = DN25, 1/2 inch (4 mm) = DN15.
• Mnemonic: Each 25-unit increase in nominal diameter roughly equals 1 inch.
• Special Sizes: DN20 corresponds to 3/4 inch (6 mm), DN32 corresponds to 1.25 inches.
• Quick Verification: Measure outer diameter with a tape measure; a 1-inch pipe should measure approximately 33.7 mm.

1 Inch Galvanised Pipe Application

1. Construction Engineering: Scaffolding crossbars, diagonal braces, temporary guardrails, construction railings, simple supports, indoor/outdoor low-pressure water supply, heating branch pipes, fire sprinkler system branch pipes.
2. Agricultural Facilities: Greenhouse frames, connecting rods, field irrigation pipes, sprinkler main pipes, livestock shed frames, simple fencing.
3. Municipal & Residential Facilities: Residential guardrails, carport supports, advertising frames, electrical conduit protection pipes, low-pressure gas service lines (must comply with gas-specific standards).
4. Industrial Applications: Compressed air piping, cooling water, low-pressure circulating water pipelines, equipment supports, structural frameworks, simple workbench frames.

Specification Selection Guide

Three key points to consider during selection

1. Pressure Requirements: 2.8mm wall thickness is suitable for low-pressure scenarios below 0.8MPa, while 3.2mm wall thickness meets standard pressure requirements up to 1.6MPa.
2. Connection Method: Threaded connections are typically used for DN25 and smaller sizes. Allow 1.5 times the outer diameter for installation clearance.
3. Corrosion Resistance: Hot-dip galvanized coating thickness must be ≥65μm and pass the copper sulfate immersion test (no reddening after 5 consecutive immersions).

Practical Tips for Selecting Accessories

When encountering dual-dimension markings like “25×15,” prioritize the DN value. In practice, a 1-inch to 1/2-inch reducer can connect pipes of different specifications. When selecting fittings, inspect the thread depth and quality on the inner wall—shallow threads may cause poor sealing. Bringing a sample to compare with the fitting is more reliable than relying solely on memorized dimensions.

Comparison of Different Standard Systems

1. Imperial Standard (Internationally Common): Nominal diameter DN25, fixed outer diameter of 33.7mm, inner diameter varies with wall thickness. SCH40 wall thickness 3.2mm, inner diameter approx. 26.9mm, suitable for general low-pressure fluids; SCH80 features thicker walls, inner diameter approx. 24.4mm, offering greater pressure resistance.
2. Metric Standard (Used in Some Countries): Approximates DN25, with outer diameters potentially 32mm or 34mm. Wall thickness is selected based on pressure rating—typically 2.8mm for low-pressure applications and 3.5mm or higher for corrosive fluids. For higher flow rates, DN32 pipe (approximately 1.25 inches) can be used, offering a larger inner diameter.

Weight Calculation for 1-Inch Galvanized Pipe

The theoretical weight of galvanized steel pipe can be calculated using the following formula: [(Outer Diameter – Wall Thickness)] × Wall Thickness × 0.02466 = kg/m (Weight per Meter)

Using a DN25 galvanized pipe (Outer Diameter 33.7mm, Wall Thickness 3.2mm) as an example: Weight per meter = [(33.7 – 3.2) × 3.2] × 0.02466 × Galvanizing weight increase factor (1.045) ≈ 2.53 kg/m

Weight per 6-meter fixed-length pipe ≈ 15.18 kg/pipe

Galvanizing Weight Increase Factor

• Conventional hot-dip galvanizing (zinc layer thickness 85μm, GB standard ordinary grade): Use 1.04 (most commonly used, suitable for most engineering scenarios).
• Heavy-duty hot-dip galvanizing (zinc coating thickness ≥120μm): Use 1.05
• Thin-walled 1-inch pipe (wall thickness ≤2.5mm): Use 1.035 (Thin-walled pipes have slightly lower zinc coating proportion, so the coefficient is appropriately reduced).

Weight Table for 6-meter 1-inch Galvanized Pipe

1-inch DN25 galvanized pipe wall thickness	Weight per meter of galvanized pipe	Total weight of 6-meter standard length
2.5mm	≈2.06kg/m	≈12.36kg
2.8mm	≈2.28kg/m	≈13.68kg
3.0mm	≈2.39kg/m	≈14.34kg
3.2mm	≈2.53kg/m	≈15.18kg
3.5mm	≈2.71kg/m	≈16.26kg

Why Choose Us?

• High-Quality Products: Available in various wall thicknesses, cut to desired lengths as required. Features uniform hot-dip galvanized coating, strictly adheres to production standards, and ensures precise dimensions.
• Trusted Manufacturer: With 15 years of industry experience, our company holds multiple certifications including ISO 9001, ISO 14001, CE, and SGS.
• Extensive Export Experience: We have successfully exported to over 120 countries, including Colombia, Kazakhstan, Indonesia, Saudi Arabia, Brazil, Maldives, Guatemala, and more.

As a professional galvanized steel pipe supplier, our factory is located in Tianjin. If you are interested in our products or wish to learn more about our company, we welcome you to visit our factory at any time.