Internal Liquid Epoxy Lining ERW Pipe 12 Inch Sch 40 for Potable Water Supply

Engineered to deliver exceptional water hygiene and superior hydraulic efficiency for municipal supply networks, this Internal Liquid Epoxy Lining ERW Pipe represents the premium standard in potable water transmission. Utilizing a versatile 12-inch nominal diameter (323.8mm OD) and a robust Schedule 40 (10.31mm WT) Electric Resistance Welded (ERW) steel base pipe, this pipeline ensures high pressure containment and structural reliability.
The interior is lined with a high-build, solvent-free liquid epoxy in strict compliance with the AWWA C210 standard and certified to NSF/ANSI/CAN 61. This food-grade lining creates an ultra-smooth, non-toxic barrier that eliminates the risk of internal rust and tuberculation, maintaining the highest water quality and reducing pumping energy costs over a decades-long service life.

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Features & Advantages

Certified Potable Water Safety: Certified to NSF/ANSI/CAN 61 and AWWA C210, ensuring zero chemical leaching, VOC emission, or taste degradation in drinking water.

Maximized Hydraulic Performance: The smooth internal liquid epoxy lining offers an exceptionally low friction coefficient (high Hazen-Williams C-factor), which prevents mineral scaling and reduces energy consumption during pumping.

Robust ERW Base Pipe: The ASTM A53/API 5L Grade B ERW carbon steel base pipe provides highly consistent wall thickness, high structural strength, and superb field weldability.

Superior Chemical & Abrasion Resistance: Liquid epoxy provides outstanding durability against chlorine, water treatment chemicals, and minor abrasive silt.

Technical Specifications

Specification Item	Detailed Description
Product Name	Internal Liquid Epoxy Lined ERW Steel Pipe
Lining Standard	AWWA C210 (Liquid-epoxy coatings and linings for steel water pipe)
Base Pipe Standard	ASTM A53 Grade B, API 5L Grade B, AWWA C200 (Welded Line Pipe)
Manufacturing Process	ERW (Electric Resistance Welding)
Nominal Pipe Size (NPS)	12 Inch (DN300)
Outer Diameter (OD)	12.75 inches (323.8 mm)
Wall Thickness (WT)	Schedule 40 (0.406 inches / 10.31 mm)
Internal Lining Type	Two-part liquid epoxy (polyamide or amine-cured)
Sanitary Certifications	NSF/ANSI/CAN 61 (potable water contact approval)
Lining Thickness	Standard 300 to 400 microns Dry Film Thickness (DFT) per AWWA C210
Pipe Ends	Beveled ends (30°~35°) with a factory bare steel cutback for field joint welding
Standard Length	5.8m, 6.0m, 11.8m, 12.0m, or customized

Product Applications

Municipal Potable Water Distribution: High-capacity city water mains, distribution pipelines, and residential water supply inlets.

Water Treatment Facility Utilities: Raw and treated water transport lines within municipal water filtration plants.

Industrial Utility Water Loops: Buried pipelines providing chilled utility water and clean process water within factories.

Commercial Building Risers: Vertical supply mains in commercial and high-rise fire/water distribution systems.

Rigorous Quality Control & Manufacturing Process

Our 12-inch internal liquid epoxy pipes are manufactured and lined under strict, modern quality control protocols:

Raw Tube Quality Inspection: Verifying the outer diameter, wall thickness (10.31mm), and weld seam of the raw ERW steel tubes to ensure compliance with ASTM A53 Grade B specifications.

Internal Surface Prep to SA 2.5: The steel interior undergoes aggressive abrasive blast cleaning (shot blasting) to achieve an SA 2.5 near-white metal finish, establishing a precise micro-roughness profile for liquid epoxy adhesion.

Automated Liquid Spraying: A specialized spray boom is driven through the pipe, applying a uniform wet film of two-part polyamide or amine-cured epoxy to the inner wall, ensuring constant thickness across the weld seam.

Controlled Curing & Testing: Lined pipes are cured under controlled temperature conditions to ensure chemical cross-linking. After curing, 100% dry film thickness checks and low-voltage Holiday testing are executed to guarantee a completely pinhole-free protective lining.

Frequently Asked Questions (FAQ)

Q1: What is the main difference between liquid epoxy lining and fusion-bonded epoxy (FBE) powder?

A: Fusion-bonded epoxy (FBE) is applied as a dry powder onto preheated steel (typically above 200°C), while liquid epoxy is a two-part wet paint applied at ambient or moderately warm temperatures. Liquid epoxy (to AWWA C210) can achieve an exceptionally smooth, glass-like finish, which significantly reduces friction loss in water pipelines, and is highly versatile for specific municipal drinking water certifications.

Q2: Is this internal liquid epoxy lining certified for direct contact with drinking water?

A: Yes, absolutely. Our liquid epoxy formulation is fully certified to NSF/ANSI/CAN 61, the premier global standard for drinking water system components. This ensures that the cured lining is entirely non-toxic, does not leach chemicals, and will not alter the taste or smell of the water.

Q3: How are the welded joints of this 12-inch pipe protected in the field?

A: The pipes are delivered with a standard bare steel cutback (50mm–100mm) at the ends. After field butt-welding and weld inspection, the joint area is cleaned. Pipeline crews or joint-coating specialists can then apply matching two-part liquid epoxy paint directly to the inner weld seam using long-reach rollers or specialized joint-coating tools to restore continuous, seamless internal protection.

Q4: Why choose Schedule 40 wall thickness for a 12-inch water pipe?

A: A 12-inch Schedule 40 pipe features a substantial 10.31mm wall thickness. This provides the necessary mechanical strength and high burst pressure capacity to easily withstand municipal water hammer surges, external soil loads during deep burial, and external road traffic overburdens.