ASTM A53 Grade B ERW Steel Pipe 4 Inch Schedule 40 Black Paint for Water Supply

Our ASTM A53 Grade B ERW Steel Pipe is engineered to deliver high reliability and structural strength for low-to-medium pressure fluid transmission, commercial building plumbing, and industrial water supply networks. Featuring a standard 4-inch nominal size and a Schedule 40 wall thickness, this pipe is manufactured via high-frequency Electric Resistance Welding (ERW) and undergoes rigorous non-destructive testing and inline sizing to ensure dependable weld seam integrity and precise dimensional accuracy.
Finished with a premium black paint coating, it offers robust temporary atmospheric corrosion protection during transit and storage. Whether deployed in municipal water grids, chilled water HVAC systems, or fire sprinkler infrastructures, our ASTM A53 Grade B pipes deliver a solid balance of high tensile strength, precise formability, and outstanding cost-efficiency.

Key Features & Advantages

Premium Grade B Mechanical Properties: Formulated with a higher carbon and manganese content compared to Grade A, delivering a superior minimum yield strength of 240 MPa (35,000 psi) and tensile strength of 415 MPa (60,000 psi) to withstand reliable hydraulic working pressures.

High-Frequency ERW Weld Integrity: Utilizing state-of-the-art inline induction welding, the longitudinal weld seam possesses identical mechanical strength to the base steel. 100% heat-treated post-weld to eliminate internal residual stresses.

Exact Dimensional Tolerance (4″ Sch 40): Standardized exactly to ASTM A53 dimensional matrices, boasting an Outside Diameter (OD) of 114.3 mm (4.500 in) and a nominal Wall Thickness (WT) of 6.02 mm (0.237 in) for seamless compatibility with standard grooved couplings, flanges, and threaded fittings.

Anti-Corrosion Black Varnish/Paint Coating: Evenly applied industrial black coating prevents flash rusting in humid climates, oceanic transit environments, and open-air construction storage sites.

100% Hydrostatic & NDT Tested: Every single length of pipe is subjected to mandatory factory hydrostatic pressure testing and online Ultrasonic Testing (UT) to guarantee zero-leakage security in critical water supply applications.

Excellent Workability: Optimized chemistry ensures superior weldability for on-site manual or automatic welding, as well as excellent ductility for threading, grooving, or slight field bending.

Technical Specifications

Parameter	Specification Details
Standard	ASTM A53 / A53M (Welded and Seamless Steel Pipe, Black and Hot-Dipped)
Manufacturing Process	ERW (Electric Resistance Welded / High-Frequency Welded)
Nominal Pipe Size (NPS)	4 Inch (DN100)
Wall Thickness Schedule	Schedule 40 (Sch 40) / Standard (STD)
Actual Outside Diameter (OD)	4.500 inches (114.3 mm)
Actual Wall Thickness (WT)	0.237 inches (6.02 mm)
Theoretical Weight	10.79 lbs/ft (16.07 kg/m )
End Finish Options	Plain Ends (Square Cut), Beveled Ends (30°±5°), or Grooved Ends for rapid coupling
Surface Coating	Black Paint Varnish, Anti-Rust Light Oil, or Bare Pipe as requested
Length Profiles	SRL (5.8m-6m), DRL (11.8m-12m), or Custom Cut Lengths

Chemical Composition (Max %)
According to ASTM A53 Grade B chemical requirements for welded pipes

Grade	Carbon (C)	Manganese (Mn)	Phosphorus (P)	Sulfur (S)	Cu / Ni / Cr / Mo / V (Combined)
Grade B (Welded)	≤ 0.30%	≤ 1.20%	≤ 0.05%	≤ 0.045%	≤ 1.00% total residual elements

Mechanical Properties
Ensuring structural stability and high-pressure load handling:

Property	Value in Metric Units	Value in Imperial Units
Minimum Yield Strength	≥ 240 MPa	≥ 35,000 psi
Minimum Tensile Strength	≥ 415 MPa	≥ 60,000 psi
Elongation in 2 in. (50.8mm)	According to standard formula (e = 625,000 A0.2 / U0.9)	Minimum 30% baseline

Product Applications

This high-strength, versatile ASTM A53 Grade B carbon steel pipe is engineered for reliable performance across standard structural and fluid transmission engineering fields. Key applications include:

Water Supply & Distribution Systems: Ideally suited for municipal water supply lines, industrial cooling water circulation, and water treatment plant piping where dependable internal pressure resistance is required.

Fire Sprinkler Systems: Widely deployed in commercial and industrial fire protection piping networks, meeting standard compliance requirements for wet and dry sprinkler systems.

HVAC & Chilled Water Lines: Excellent for heating, ventilation, and air conditioning infrastructure to transport chilled water, condenser water, and low-pressure steam.

Structural & Engineering Supports: Utilizing the mechanical properties of Grade B steel, these 4-inch Schedule 40 pipes are frequently used as structural columns, protective bollards, scaffolding, and architectural handrails.

Plumbing & Non-Corrosive Fluid Transport: Suitable for conveying air, gas, steam, and other non-corrosive fluids in chemical processing plants and manufacturing facilities.

Rigorous Quality Control & Manufacturing Process

To assist our global clients with local municipal and engineering board approvals, every shipment is backed by absolute transparency:

Mill Test Certificate (MTC): Issued fully compliant with EN 10204 3.1, validating chemical analysis, mechanical tensile values, flattening tests, and hydrostatic test pressure benchmarks.

Third-Party Inspection (TPI): Fully receptive and routine cooperation with independent testing bodies including SGS, Bureau Veritas (BV), Intertek, and Lloyd’s Register for pre-shipment dimensional check and visual audit.

Traceability: Heat numbers and lot identification tracking codes are precisely stenciled onto each pipe body for foolproof project material auditing.

Frequently Asked Questions (FAQ)

Q: What is the difference between ASTM A53 Grade A and Grade B steel pipes?

A: The primary difference lies in their mechanical properties and chemical composition. Grade B has a higher carbon and manganese content than Grade A, resulting in higher tensile strength and yield strength:
Grade B: Yield Strength ≥ 240 MPa (35, 000 psi); Tensile Strength ≥ 415 MPa ( 60, 000 psi).
Grade A: Yield Strength ≥ 205 MPa (30, 000 psi); Tensile Strength ≥ 330 MPa ( 48, 000 psi).
Grade B is much more widely preferred in industrial and fluid engineering because it handles higher working pressures and structuralloads.

Q: What does “ERW” stand for, and is it safe for high-pressure water supply?

A: ERW stands for Electric Resistance Welding. It means the steel pipe is manufactured by cold-forming a steel strip into a cylindrical shape and welding the longitudinal seam using high-frequency electrical current.Our ERW pipes undergo strict heat treatment of the weld seam (ultrasonic or eddy current testing) to ensure the weld zone is as strong as the parent material. It is fully certified and highly safe for standard municipal and industrial water supply lines under regulated pressure limits.

Q: What are the exact dimensions of a “4 Inch Schedule 40” pipe?

A: In the ASME/ANSI B36.10M standard, a 4-inch Schedule 40 pipe corresponds to the following precise physical dimensions:
Nominal Pipe Size (NPS): 4 inch
Outer Diameter (0D): 4.500 inches (114.3 mm)
Wall Thickness (WT): 0.237 inches (6.02 mm)
Inside Diameter (ID): Approx. 4.026 inches (102.26 mm)