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Blog Posts

The Reasons to Choose Weld Neck Flanges

API International

November 5, 2026

A weld neck flange typically costs more and takes longer to install than a slip-on or threaded flange. Even so, it remains the industry standard for high-pressure and critical piping systems. In this guide, we explain the design features behind

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How States Specify NSF/ANSI/CAN 60, 61 & 372

API International

October 31, 2026

Nearly every U.S. state requires drinking water system components to comply with NSF/ANSI/CAN 61. A survey conducted by NSF and the Association of State Drinking Water Administrators (ASDWA) found that 49 of 50 U.S. states have legislation, regulations, or policies

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Choosing Between Weld Neck and Threaded Flanges

API International

October 30, 2026

Weld neck flanges and threaded flanges both join a flange to pipe, but in opposite ways. A weld neck flange is permanently welded to the pipe, while a threaded flange screws directly onto threaded pipe ends. This single difference affects

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The NSF/ANSI/CAN 61 Certification Process for Flanges

API International

October 23, 2026

NSF has been testing and certifying drinking water system components for more than 70 years. The certification process is organized and follows a seven-step process that is applied across a wide range of products, including valves, flanges, and other piping

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Weld Neck Flange Welding Procedure Explained

API International

October 15, 2026

Connecting a weld neck flange to pipe requires a full-penetration butt weld, which provides the joint’s strength and structural integrity. Because the connection depends on weld quality, proper preparation, alignment, and procedure qualification are essential requirements. This guide explains the

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How NSF/ANSI/CAN 61 Aligns With U.S. EPA PFAS Regulations

API International

October 9, 2026

On April 10, 2024, the EPA finalized its first National Primary Drinking Water Regulation for PFAS, establishing legally enforceable limits for six compounds in municipal water systems. NSF/ANSI/CAN 61 was updated the same year to match the EPA’s maximum contaminant

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Why the Safe Drinking Water Act Requires Lead-Free Flanges

API International

October 2, 2026

“Lead-free” is far more than a marketing phrase on a flange spec sheet – it is a strict requirement mandated by federal law. Any flange used in a drinking water system must meet this requirement, which is why certified flanges

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How NSF Certification Is Earned

API International

September 24, 2026

An NSF certification mark can look like just another stamp on a spec sheet, but in reality, a rigorous, multi-step process stands behind it. Achieving true NSF certification requires independent chemical testing, a full manufacturing facility audit, and mandatory ongoing

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Types and Applications of Weld Neck Flanges

API International

September 21, 2026

Not every weld neck flange looks identical. The tapered hub and butt-weld end are constant, but the face type, hub length, and bore can all change to fit a specific joint or industry requirement. This guide covers the main types

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NSF 372 Certification: Technical Requirements and Testing

API International

September 18, 2026

The NSF-372 standard confirms one primary requirement: that a product qualifies as lead-free under federal law. Determining compliance requires more than checking whether a listed alloy contains lead. In this article, we cover what the NSF-372 standard measures, how the

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API International Blog

Flanges, Valve Accessories &
Piping Industry Knowledge

Our blog is designed to help you make confident and informed decisions when selecting flanges for your project. Our team of engineers and subject matter experts specialize in AWWA, ANSI/ASME, DIN, and more, providing practical guidance backed by API International.