No mundo da tubulação industrial, soluções econômicas e eficientes são essenciais – especialmente em sistemas onde as condições de pressão e temperatura são moderadas. Entre várias opções de flanges, o flange de soldagem plana (also known as a slip-on flange) stands out as a practical and economical choice for low-pressure pipeline systems.

This article explores the advantages, technical features, aplicações, métodos de instalação, and material options of flat welding flanges. Whether you’re a pipeline contractor, engineer, or procurement specialist, this guide will help you understand why flat welding flanges are a popular option in industries such as water treatment, AVAC, petroquímica, and general construction.

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O que é um flange de soldagem plano?

UM flange de soldagem plana is a type of pipe flange that slides over the pipe and is then fillet welded on both the inside and outside to provide strength and leak-tightness. Ao contrário dos flanges de pescoço soldado, flat welding flanges do not have a hub and are ideal for applications where pressure is relatively low and where space and budget constraints matter.

Standard references include:

• ASME B16.5 – For pipe flanges and flanged fittings

• EN 1092-1 Tipo 01 ou 02 – For European specifications

• JIS B2220 – For Japanese standard flanges

sasa oblonga manufactures flat welding flanges in a variety of sizes and materials to meet international standards and project specifications.

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Design Features of Flat Welding Flanges

• Tamanho do furo: Slightly larger than the pipe outer diameter to allow easy insertion

• Rosto levantado (RF) ou face plana (FF): Options depending on sealing needs

• No long tapered hub: Compact and lightweight

• Fillet welds: Applied on both sides to secure the pipe

• Furos de parafusos: Equally spaced to match standard bolt patterns

The simple geometry and easy alignment make flat welding flanges suitable for quick assembly, reparar, and field modifications.

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Advantages of Flat Welding Flanges

1. Cost-Effective Solution

Flat welding flanges are more affordable than weld neck flanges due to:

• Less material used

• Usinagem mais fácil

• Faster installation time

• Lower welding complexity

This makes them ideal for budget-sensitive projects and large-scale piping networks.

2. Easy Installation and Alignment

These flanges are easier to align with pipes during welding. Deles slip-on design accommodates minor misalignment and allows quick positioning.

• Saves labor time

• Reduces risk of installation errors

• No need for complex beveling as with butt-weld connections

3. Lightweight and Space-Saving

The absence of a hub reduces the overall weight and space requirement, making them suitable for:

• Compact equipment layouts

• Lightweight supports

• Skid-mounted systems

4. Versatility in Applications

Flat welding flanges can be used for:

• Fluids (água, ar, óleo)

• Low-pressure steam

• Non-hazardous gases

• Non-corrosive liquids

They are common in non-critical systems that don’t require high structural strength.

5. Wide Availability and Customization

Flat welding flanges are widely produced and available in:

• Aulas de pressão: 150#, 300#, PN10, PN16

• Tamanhos: DN15 to DN2000

• Facing types: RF, FF, and RTJ

• Materiais: Aço carbono, aço inoxidável, liga de aço

sasa oblonga offers quick delivery of standard and customized flat welding flanges for global projects.

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Aplicações típicas de flanges de soldagem plana

● Water Supply and Drainage

Used in municipal pipelines, estações de bombeamento, and wastewater treatment plants due to corrosion-resistant coatings and simple connections.

● Sistemas HVAC

Flat welding flanges are ideal for air conditioning and heating pipelines, offering quick on-site adjustments and tight seals.

● Plantas Químicas e Petroquímicas

Applied in non-critical service pipelines carrying mild chemicals, solventes, or low-pressure steam.

● Processamento de Alimentos e Bebidas

When made from stainless steel, flat welding flanges are used in hygienic piping for beverages, dairy, and brewing.

● Power Plants and Energy Facilities

Applied in auxiliary systems such as cooling water, low-pressure return lines, and drainage networks.

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Installation Procedure

Installing a flat welding flange requires the following steps:

1. Preparação de tubos

   • Cut the pipe to the required length

   • Clean the pipe end to remove oil, sujeira, or burrs

2. Colocação do Flange

   • Deslize o flange sobre a extremidade do tubo

   • Align the bolt holes with mating flange or template

3. Soldagem

   • Perform a fillet weld on the inner side of the pipe end

   • Acompanhe com um solda de filete externa around the flange face

4. Gasket Insertion and Bolt Tightening

   • Place the gasket (ferida em espiral, borracha, etc.)

   • Insert bolts and tighten in a cross-pattern using a torque wrench

   • Follow appropriate torque sequence to ensure uniform pressure

5. Testing and Inspection

   • Conduct hydrostatic or pneumatic testing to check for leaks

   • Visually inspect welds for quality and completeness

sasa oblonga supplies flanges with precision machining, making installation smooth and consistent.

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Opções de materiais

Flat welding flanges are manufactured in a variety of materials, incluindo:

• Aço carbono (ASTM A105, Um P245GH): Affordable and strong for general use

• Aço inoxidável (304, 316, 321): Corrosion-resistant for chemical and food applications

• Liga de aço (F11, F22): Used in moderate temperature and pressure environments

• Aço Inoxidável Duplex: Offers superior strength and corrosion resistance

• Ligas de Níquel: For specialized systems requiring chemical resistance

Surface treatments may include:

• Galvanizing

• Epoxy coating

• Passivação

• Pickling and polishing

sasa oblonga offers material traceability, EN10204 3.1 certificados, and special coatings upon request.

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Classificações e padrões de pressão

Flat welding flanges are designed for aplicações de pressão baixa a moderada:

• ASME B16.5 Aulas: 150#, 300#

• EN 1092-1 Aulas de pressão: PN6, PN10, PN16

• JIS B2220 Aulas: 5K, 10K, 16K

Always select the correct pressure class and material based on system pressure, temperatura, e tipo de fluido.

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Inspeção e Controle de Qualidade

To ensure safety and performance, all flat welding flanges must undergo:

• Inspeção dimensional

• Verificação de materiais (PMI)

• Flatness and facing finish check (Ra ≤ 3.2 µm)

• Bolt hole alignment

• Visual inspection of welds (if factory-welded)

• Hydro or air leak testing if assembled

sasa oblonga mantém ISO 9001-certified quality systems and third-party inspection cooperation (GV, BV, TUV).

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Por que escolher sasaflange?

sasa oblonga is a professional flange manufacturer serving global customers in energy, petroquímico, água, e projetos de infraestrutura. As principais vantagens incluem:

• Full range of flat welding flanges in ASME, EN, DIN, JIS, and GOST standards

• Manufacturing in stainless steel, aço carbono, e ligas especiais

• Usinagem CNC, surface finishing, and drilling

• 3.1/3.2 certified quality control and fast export support

• Custom sizes, revestimentos, and gasket kits available

For budget-conscious projects or low-pressure pipelines, sasa oblonga delivers reliable flanged solutions with fast turnaround.

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Conclusão

Flat welding flanges are a smart and economical solution for low-pressure pipeline systems across a wide range of industries. Sua facilidade de instalação, eficiência de custos, and flexibility make them ideal for non-critical yet essential piping applications.

By sourcing high-quality flat welding flanges from sasa oblonga, customers benefit from certified materials, international compliance, and expert support—ensuring the success of every pipeline project.

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