AWWA and JIS Standards of Flanges? - YENA Engineering

28 Jul.,2025

 

AWWA and JIS Standards of Flanges? - YENA Engineering

A flange is a protruded ridge, lip, or rim, either external or internal, that serves to increase strength; for easy attachment/transfer of contact force with another object; or for stabilizing and guiding the movements of a machine or its parts. For example, sectional beams often have at least one flange that carries most of the load and that are connected by a web joining the flanges together. Pipes may also be fitted with flanges, which provide attachments. Nuts and bolts may include them to spread the clamping force over an increased area. The term “flange” is also used as a kind of tool used to form them.

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Common Flange Types and Characteristics

Pipe flanges are classified according to how they are attached to the pipe. Types of pipe flange include:

Weld neck flanges are butt welded onto the end of a pipe, providing a flange that is suitable for high temperature and pressure.

Threaded flanges have an internal (female) thread, a threaded pipe is screwed into it. This is relatively easy to fit but not suitable for high pressure and temperature.

Socket-welded flanges have a plain hole with a shoulder at the bottom. The pipe is inserted into the hole to butt against the shoulder and is then welded into place with a fillet weld around the outside. This is used for small diameter pipes operating at low pressure.

Slip-on flanges also have a plain hole but without the shoulder. Fillet welds are applied to the pipe on both sides of the flange.

Lapped flanges consist of two parts; a stub end and a backing flange. The stub end is butt-welded to the end of the pipe and includes a small flange without any holes. The backing flange can slide over the stub end and provides holes to bolt to another flange. This arrangement allows disassembly in confined spaces.

Blind flanges are a form of blanking plate that is bolted to another pipe flange to isolate a section of piping or terminate piping.

Flange Standards

A flange standard lays down the dimensions, surface finish, facing type, marking, material and technical specifications. There are Flange Standardizations made by various institutions. For example institutions like ASME, AWWA, JIS, ISO, CEN have their Flange Standards. But in this Blog, we are gonna detailing AWWA and JIS Standards for Flanges.

What is AWWA ?

The American Water Works Association is an international, nonprofit, scientific, and educational society dedicated to providing total water solutions assuring the effective management of water. Founded in , the Association is the largest organization of water supply professionals in the world. 

AWWA’s membership includes over 4,300 utilities that supply roughly 80 percent of the US’s drinking water and treat almost half of the nation’s wastewater. Their 51,000 total members represent the full spectrum of the water community: public water and wastewater systems, environmental advocates, scientists, academicians, and others who hold a genuine interest in water.

AWWA Flanges

American Waterworks Association flanges are typically designed for low-pressure applications (300 psi or less). They are the opposite of API flanges and can be found in a wide variety of assemblies where the temperature is ambient and the medium is not corrosive. In most cases, it can be used not only for the transport of wells and sewers but also for fertilizer pipes and pipes with minimal pressure requirements.

AWWA flange standards differ in several respects from ANSI (American National Standards Institute) and ASME (American Society of Mechanical Engineers) certificates, especially in their specificity: AWWA standards do not assess more broadly, but specifically properties that affect drinking water use.

AWWA Certified Flange Types

Also unlike ANSI and ASME standards, AWWA Flange Standards do not address welded auxiliary connections or tapping. They cover a very specific range of flange types, including:

  • Slip-on Ring and Hub Type Flanges, fitted over a pipe
  • Blind Flanges, to seal or close a pipe or vessel
  • Threaded Iron Flanges, fitted to externally threaded pipes

Some AWWA Flange Standards

AWWA C207: AWWA C207 steel flanges are usually composed of unalloyed carbon steel or a stainless steel version and are usually designed as a snap ring or structure of deaf discs. By design, they have no ring joints or raised surfaces and are usually sealed with rubber gaskets. Due to their cost and weight compared to other flange types, they are becoming increasingly popular in design work for structural steel types that require bonding or filling a gap between existing flanges. More Specifically, the American Water Works Association has published specification C207 to provide a standard for carbon steel rings and blinds. AWWA is a bit tolerant about which steel can also be used. C207 limits the carbon, phosphorus and sulfur content to 0.35%, 0.04%and 0.05%, respectively. Low requirements for minimum yield and tensile strength 32ksi and 50ksi respectively and enable many commercially rich brands of carbon steel, such as A516-70, A36, A105, A181-60.

AWWA C228-19: The purpose of this standard is to provide the minimum requirements for quicklime and hydrated lime, including physical, chemical, sampling, packaging, shipping, and testing requirements.

This standard can be referenced in documents for purchasing and receiving quicklime and hydrated lime and can be used as a guide for testing the physical and chemical properties of quicklime and hydrated lime samples. The stipulations of this standard apply when this document has been referenced and then only to quicklime and hydrated lime used in the treatment of potable water, wastewater, or reclaimed water.

Industries and Applications

The waterworks-specific AWWA Standard Flanges have been developed to meet light-duty applications, typically requiring performance at or below 300 psi. The most common pressure range is AWWA Class D, rated at 175 psi for sizes under 12 inches and 150 psi for larger sizes.

Common applications of AWWA Flanges include:

  • Waterworks
  • Slurry
  • Waste water
  • Plant piping

As a low-pressure piping solution, AWWA Standard Flanges can be an effective cost saver over ANSI or ASME forged flanges. These flanges, designed for oil, steam, or chemical applications and their demand for high pressure, are typically more expensive and less necessary for low-pressure piping.

What is JIS ?

Japanese Industrial Standards (JIS) are the standards used for industrial activities in Japan, coordinated by the Japanese Industrial Standards Committee (JISC) and published by the Japanese Standards Association (JSA). The JISC is composed of many nationwide committees and plays a vital role in standardizing activities across Japan.

Goto Haihao Group to know more.

JIS Flanges

For metric sizes, Japan Industrial Standard is yet another option. Provided in JIS5K, JIS10K, JIS15K, and JISK20K pressure classes, Yena Engineering can offer Slip-On, Blind, and Weld Neck, Socket Weld, and varieties.

Much like DIN / metric flanges, the JIS flange specification offers a slightly wider variety of slip weld configurations for space limitations and suitability for existing pipeline equipment. For instance, a customer can request a slip-on with or without a hub as standard, or even a ring-type flange, and all of this is within the same B specification.

JIS flanges are widely used in pressure equipment and pipe assemblies exported from Japan. Many large and offshore vessels sailing in international waters and serving the Pacific use equipment conforming to this standard because parts and services of this specification are common.

Some JIS Flange Standards

JIS B: The most commonly used JIS B 5k Flange Face Type is raised face. Besides the raised type, the other JIS B Flanges include types like flat face, Groove and Tongue Flange, and ring type joint. JIS B Flange Material used by manufacturers to produce these flanges includes metals like stainless steel, carbon steel, alloy steel & nickel alloys. 

Industries and Applications

Key markets and industries for JIS flanges are;

  • Nuclear power (mostly seamless).
  • Heavy oil refineries.
  • Bitumen upgraders.
  • Petrochemicals and acids.

JIS Flanges Application has lots of applications such as to Connect Pipe & Tubes in Power, Petroleum, Construction, Chemical, Gas, Shipbuilding, Metallurgy, etc.

You may check also this article: Forged Flanges – Production Method and Properties

References:

https://www.awwa.org
https://www.unifiedalloys.com/blog/flanges-101/
http://www.coastalflange.com/awwa.html
https://www.texasflange.com/flange-specs/awwa/
http://www.pipingpipeline.com/awwa-c207-steel-pipe-flg.html

Comparing the JIS B Flange and EN-1 Flange

When it comes to piping systems, choosing the right flange is crucial for ensuring a secure and reliable connection. Two of the most widely used flanges in the industry are the JIS B flange and the EN-1 flange. Each of these flanges is designed to meet specific international standards, making them suitable for different applications and industries. Let’s delve into the unique advantages, applications, and specifications of these two flanges to help you determine which one is best suited for your project.

Advantages and Applications of the JIS B Flange

The JIS B flange is manufactured according to Japanese Industrial Standards (JIS), which are recognized globally for their precision and reliability. This flange is widely used in industries across Asia, particularly in Japan, where JIS standards are the norm.

One of the primary advantages of the JIS B flange is its compatibility with Asian-manufactured equipment and piping systems. This makes it an ideal choice for projects involving machinery or infrastructure developed according to JIS standards. Additionally, the JIS B flange is known for its robust design and ability to withstand high-pressure environments, making it suitable for applications in oil and gas, petrochemical, and power generation industries.

In terms of JIS B flange dimensions, these flanges are available in a variety of sizes to accommodate different pipe diameters and pressure ratings. Whether you need a flange for a small pipeline or a large industrial installation, the JIS B flange offers the flexibility and reliability you need to ensure a secure connection.

Exploring the Benefits and Uses of the EN-1 Flange

The EN-1 flange is manufactured according to European standards, specifically the EN-1 standard, which is widely recognized across Europe and beyond. This flange is commonly used in European-manufactured piping systems and is designed to meet the rigorous requirements of industries such as chemical processing, water treatment, and HVAC.

One of the key advantages of the EN-1 flange is its versatility. This flange is available in a wide range of materials, including stainless steel, carbon steel, and alloy steel, allowing it to be used in various applications, from low-pressure water systems to high-pressure chemical pipelines. Additionally, the EN -1 flange dimensions are standardized across Europe, ensuring compatibility with European equipment and piping systems.

The EN-1 flange is also known for its ease of installation and maintenance. Its design allows for quick and efficient assembly, reducing downtime and ensuring that your project stays on schedule. Furthermore, the EN-1 flange is designed to provide a leak-proof connection, even in challenging environments, making it a reliable choice for critical applications.

Making the Right Choice: JIS B Flange vs. EN-1 Flange

When deciding between the JIS B flange and the EN-1 flange, it’s important to consider the specific requirements of your project. If your project involves equipment or piping systems manufactured in Asia, particularly Japan, the JIS B flange is likely the best choice due to its compatibility and robust design. On the other hand, if your project is based in Europe or involves European standards, the EN-1 flange offers the versatility and ease of use that you need.

Both flanges offer high-quality, reliable connections, but their suitability will depend on the standards and requirements of your specific project. By choosing the right flange, you can ensure a secure, durable, and leak-proof connection that meets the demands of your industry.

For more information, please visit JIS B carbon steel flange.