Square Flanges

Square flange is a square shape flange that used in between pipe to pipe or pipe to components connections, like valves, tees, and elbows. Square flanges are made in accordance to JIS B2291 / JIS F7806 standard. It links the JIS standard nominal bore size pipes together in a hydraulic system. By using square flanges, you can assure a continuous flow of liquids across stainless steel pipes or other hydraulic systems. Square flanges are mostly used in hydraulic oil systems or steam lines.

Among the many international standards, the JIS B2291 and JIS F7806 standards hold particular significance when it comes to square flanges. These standards enhance safety, reliability, and compatibility while reducing maintenance costs and ensuring compliance with international regulations.

• JIS B2291: A set of specifications established by the Japanese Industrial Standards (JIS) for hydraulic fluid power — flange connections. These standards govern the design, dimensions, and performance of square flanges used in hydraulic systems. Their global recognition stems from the precision and compatibility they ensure in hydraulic applications.
• JIS F7806: Specific to marine flanges, particularly in the context of shipbuilding and maritime applications. These standards, defined by the Japanese Industrial Standards Committee, outline the requirements for square flanges used in the marine industry. Their primary role is to ensure safety and reliability in the challenging and corrosive marine environment.

The materials used to fabricate square flanges are steel (SF440A) and stainless steel (SS316). In many industries, stainless steel (SS316) is a preferred choice due to its strong resistance to corrosion. Stainless steel has the capability of withstanding high pressures and temperatures, as well as lasting longer. Thus, SS316 solves the corrosion problem which is caused by environmental changes, chemical interaction, and other factors.

Steel (SF440A) is also known as carbon steel, and it is one of the most fundamental steel types utilised in manufacturing industries. Carbon steel flanges have enhanced hardness and strength, which manifests themselves throughout manufacturing. Carbon steel flanges also have excellent corrosion resistance, heat resistance, and durability.

Chemical Composition:

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Other Properties:

The sizes of square flanges range from 1/4" to 6" in nominal bore sizes . Pressure rating of square flanges are available in 210 kg/cm², 280 kg/cm², and 350 kg/cm².

Oring and Flat Square Blind Flanges

The only available connection for square flanges is socket weld where the connection sides of pipes need to be plain ended. There are various types of configurations for square flange: SHAB, SSAB, KAB, LSA, and Blind Flange.

SHAB series is a complete set of 210 kg/cm² square flange that combined by hexagon hex bolts with nuts, while SSAB series is a complete set of 210 kg/cm² square flange combined by a socket cap screw. For KAB series, it is a complete set of 280 kg/cm² or 350 kg/cm² square flange combined by hexagon hex bolts with nuts.

The flange body of SHAB is larger than SSAB. Complete set of square flange includes male flange (flat side), female flange (o ring side), o ring, and bolts. The female flange is identified as A and male flange is identified as B. Thus, the complete set is AB.

LSA is a special type Oring side square flange where the internal flow is in L shaped. Blind flanges are used to seal the flow at the end of a piping system. They are typically used to run a pressure testing of fluids through vessels or pipes. For the termination of hydraulic system, only one side of blind flange is used, either Oring side or flat side.

SHAB & SSAB Square Flanges

Plumbing and HVAC Systems

In plumbing and HVAC (Heating, Ventilation, and Air Conditioning) systems, square flanges are used to connect pipes, valves, and other components. They ensure leak-proof connections, preventing water or gas leaks that could lead to damage and safety hazards.

Oil and Gas Industry

In the oil and gas industry, square flanges are essential for connecting pipelines, valves, and pumps. The robust design of square flanges helps maintain the integrity of the system, even under high-pressure conditions.

Chemical Processing

Chemical processing plants rely on square flanges to connect various pieces of equipment and transport corrosive fluids. These flanges are often made from materials that resist chemical corrosion.

Construction and Structural Engineering

Square flanges find applications in construction and structural engineering projects. They are used in frameworks and supports, providing stability and strength to structures.

Automotive and Aerospace

In the automotive and aerospace industries, square flanges are employed in various components, including engines and exhaust systems. They help maintain the structural integrity of these critical systems.

Square flanges are essential in sectors which apply high-pressure equipment. They are utilized for pipe-to-pipe connections as well as pipe-to-other-component connections. It is commonly used as a tool for pipe fittings. Square flanges are not suggested for big diameter pipes or high torque situations. Instead, small diameter pipes can be utilized in conjunction with square flanges. Square flanges can be used to connect hydraulic systems in the following sectors to ensure continuous flow of liquids:

• Water channels
• Plumbing activities
• Petrochemical industries
• Oil and gas industry — for pipe connections

• Quality Assurance: Adhering to JIS standards guarantees a certain level of quality and performance. This can lead to fewer defects, improved reliability, and enhanced safety in products and systems.
• Global Recognition: While JIS standards are Japanese in origin, they are recognized and used internationally. Complying with these standards can facilitate trade and collaboration with companies and industries around the world.
• Reduced Risk: Following established standards can mitigate risks associated with product failure, safety hazards, and legal liabilities. It provides a framework for design, production, and testing, reducing uncertainty.
• Long-Term Cost Savings: While initial compliance with standards may require an investment, it can lead to long-term cost savings through reduced maintenance, fewer product recalls, and improved overall product lifespan.

Square Flanges are used for high pressure hydraulic applications up to 350kgf/cm² . In order to use and assemble square flanges safely, it is important to know the right procedures and torque range for assembly.

Square Flanges made in accordance with JIS B2291 / JIS F7806 standard are connecting pieces that link Japanese Industrial Standards nominal bore size pipes together and have a working pressure of up to 350kgf/cm². The pipes used should be of hydraulic seamless design and suitable for high pressure applications.

It is important to note that every hydraulic system requires some form of fitting installation. Hence, proper fabrication and installation are essential for leak free performance, the overall efficiency, and general appearance of any system. In order to use and assemble Square Flanges safely, it is essential to know the right procedures. Do watch our youtube video and our instructions below carefully!

Below are the instructions for assembly of Square Flanges.

STEP 1

Ensure the sealed surface is free from scratches and contamination. Lubricate with system fluid or any compatible lubricant on the surface of the O-ring portion.

STEP 2

Position the flange. Place the bolt on the bolt hole and bolt through it.

STEP 3

Tighten the bolts with nuts by hand. Torque the bolts gradually in diagonal sequence.

STEP 4

Tighten the bolts with nuts by wrench.

Square Flanges can be found in the IMPA Marine Stores Guide, which is the world’s leading reference guide for maritime purchasing and supply.

For details on the reference codes of square flanges, please kindly see below:

SHA SQUARE FLANGES:

SHB SQUARE FLANGES:

SSA SQUARE FLANGES:

SSB SQUARE FLANGES: