When it comes to potable water systems, selecting the correct flange material is more than just an engineering decision — it’s a public health priority. The materials used in water pipelines, арматура, and flanges must meet stringent safety standards to prevent contamination, leaching, и коррозия, all while maintaining mechanical strength and longevity.

Так, what flange material is best for potable water? This comprehensive guide will walk you through the ideal options, международные стандарты, and key considerations when choosing flanges for drinking water distribution, treatment, and storage systems.

В SASA FLANGE, we provide flange solutions that are fully compliant with health and safety codes — trusted by water utilities, infrastructure contractors, and public service engineers worldwide.

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Why Flange Material Matters in Potable Water Systems

Фланцы используются для соединения труб., клапаны, and equipment across all segments of a potable water system — from treatment plants to underground distribution mains. The material used in these flanges must meet specific requirements:

✅ Non-toxic and non-leaching

Materials must not release harmful substances such as lead, никель, or cadmium into the water.

✅ Corrosion-resistant

Flanges should withstand constant water exposure and resist rust, питтинг, and scaling.

✅ Durable and pressure-rated

The material must maintain mechanical strength for decades under varying pressure conditions.

✅ Certifiable to drinking water standards

Acceptable materials must comply with international potable water certifications such as:

• НФС/АНСИ 61 (США)

• WRAS (UK)

• DVGW (Германия)

• AS/NZS 4020 (Australia)

• ГБ/Т 17219 (Китай)

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Approved Flange Materials for Potable Water

Let’s explore the most commonly approved and recommended flange materials for potable water piping systems:

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1. Нержавеющая сталь (304л / 316л)

Обзор:
Stainless steel flanges are widely used for potable water due to their отличная устойчивость к коррозии, non-leaching properties, и длительный срок службы. Grades like 304л и 316л are low in carbon and suitable for both cold and hot water systems.

Преимущества:

• Long-term durability

• Hygienic and easy to clean

• NSF 61 and WRAS certified (depending on source)

Приложения:

• Drinking water pipelines

• Pump stations

• Water treatment tanks and skids

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2. Ductile Iron (Epoxy-Coated)

Обзор:
Ductile iron offers high strength and cost efficiency but must be coated internally and externally to prevent corrosion. Flanges made from ductile iron are typically lined with fusion-bonded epoxy (ФБЕ) или epoxy paint that complies with drinking water standards.

Преимущества:

• High mechanical strength

• Cost-effective for large diameters

• Approved under many national standards when coated

Приложения:

• Municipal pipelines

• Large valve connections

• Fire protection and water mains

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3. Brass / Bronze (Lead-Free Alloys)

Обзор:
In smaller diameter systems, lead-free brass or bronze flanges иногда используются, especially in residential or building plumbing. They must be certified to lead-free requirements, especially in the U.S. under the Safe Drinking Water Act.

Преимущества:

• Corrosion-resistant in neutral pH water

• Good machinability

• Suitable for fittings and small-bore piping

Приложения:

• Domestic plumbing

• Meter connections

• Indoor water distribution

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4. PVC / CPVC (Plastic Flanges)

Обзор:
In non-metallic piping systems, especially in residential, irrigation, or light industrial potable water applications, plastic flanges made from PVC or CPVC may be used. These materials must also be tested and approved under drinking water safety standards.

Преимущества:

• Corrosion-proof

• Lightweight and easy to install

• Low cost

Приложения:

• Water tanks

• Системы низкого давления

• Temporary piping lines

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5. HDG Carbon Steel (Not Preferred)

Обзор:
Горячая оцинковка (HDG) углеродистая сталь flanges are sometimes used in non-corrosive, low-purity water systems, but they are generally not recommended for critical potable water use due to the potential for zinc leaching, масштабирование, и coating degradation через некоторое время.

Use only with proper approvals and in short-term, низкого давления, or transitional settings.

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Flange Type Recommendations for Potable Water Systems

Regardless of the material, the following flange types are common in potable water systems:

• Накладные фланцы: Economical and easy to align, suitable for general water lines

• Фланцы с приварной горловиной: For high-pressure or large-diameter lines requiring strength and leak-proof performance

• Слепые фланцы: Used to close off pipe ends or create access points

• Резьбовые фланцы: Typically used in smaller pipelines or with plastic piping

• Фланцы внахлестку: Ideal when frequent dismantling is required, such as in filters or tanks

SASA FLANGE manufactures all of these types in stainless steel and ductile iron for potable water service, with optional certifications and coatings to meet national and international safety standards.

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Gasket and Bolt Considerations

Flange performance in potable water systems also depends on compatible sealing and fastening components:

Прокладки:

• EPDM (Ethylene Propylene Diene Monomer) gaskets are widely approved for potable water use.

• Avoid gaskets containing asbestos or industrial-grade rubbers.

Bolts:

• Использовать stainless steel bolts или zinc-coated bolts approved for potable water environments.

• Ensure the entire flange assembly is corrosion-resistant and non-leaching.

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Certifications to Look For

When selecting flange materials for drinking water applications, always verify the following certifications:

• НФС/АНСИ 61 (США)

• WRAS (UK)

• ACS (France)

• DVGW W270 (Германия)

• AS/NZS 4020 (Australia)

• ГБ/Т 17219 (Китай)

SASA FLANGE provides stainless steel and epoxy-coated ductile iron flanges tested and certified according to customer region and project requirements.

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Typical Applications for Potable Water Flanges

• Municipal water supply lines

• Underground water distribution mains

• Water treatment facilities

• Booster pump stations

• RO and UF membrane skids

• Building water systems

• Irrigation and agricultural supply

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Почему выбирают SASA FLANGE for Potable Water Projects?

SASA FLANGE is a leading manufacturer of high-quality flanges for waterworks and infrastructure projects worldwide. With a full range of materials and sizes, мы предлагаем:

• Stainless steel 304L / 316L flanges with potable water approval

• Ductile iron flanges with NSF-certified epoxy coatings

• Custom fabrication and pressure classes from PN10 to PN40 and Class 150 к 600

• Third-party inspection and 3.1 / 3.2 сертификация

• Fast global delivery and full export documentation

Whether you’re building a new water treatment plant or repairing a distribution line, SASA FLANGE provides safe, tested, and reliable flange solutions — trusted in potable water systems around the world.

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Заключение

Так, what flange material is best for potable water? The answer depends on your application, давление, and regulatory requirements — but in general:

• Нержавеющая сталь (304L/316L) is the gold standard for safety, долговечность, and hygiene.

• Epoxy-coated ductile iron is ideal for large municipal and infrastructure pipelines.

• Plastic or brass flanges are suited for low-pressure and indoor applications, provided they are lead-free and certified.

No matter the material, ensure your flanges are certified for drinking water use and installed with compatible gaskets and bolts.

Выбирать SASA FLANGE for flange materials you can trust — safe for people, strong for infrastructure.