A Step-by-Step Guide for Engineers and Industrial Buyers

Flanşlar boru sistemlerinde önemli bileşenlerdir, güvenliği sağlayan mekanik konektörler görevi görür, sızdırmaz, ve borular arasındaki servis yapılabilir bağlantılar, vanalar, pompalar, ve ekipman. But with so many standards, basınç değerleri, and sizes available, one key question arises — how to know the correct flange size

Bu makalede, Sasaflance explains how to identify the correct flange size for your application, including the key dimensions, measurement techniques, and reference standards. Whether you are sourcing parts for a new project or replacing an existing flange, this guide will help you avoid errors and ensure proper system performance.

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Why Choosing the Right Flange Size Matters

Selecting the wrong flange size can lead to misalignment, pressure failures, increased leakage risk, and costly rework. Getting the flange size right is critical to

• Ensuring system compatibility

• Meeting pressure and temperature requirements

• Achieving proper sealing with gaskets

• Simplifying installation and maintenance

• Avoiding costly downtime or safety issues

Şu tarihte: Sasaflance, we support customers in choosing flange dimensions that comply with global standards such as ASME, EN, DIN, ve JIS.

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What Are the Key Flange Size Parameters

To identify or confirm the correct flange size, you need to understand and measure several key dimensions

1. Nominal Boru Boyutu (NPS'ler) veya DN

This refers to the size of the pipe the flange is intended to connect. In North America, NPS'ler (in inches) kullanıldı. In Europe and other regions, DN (diameter nominal in mm) applies.

2. Basınç Değeri (Class or PN)

Defines the maximum pressure a flange can withstand. Common ASME classes are 150, 300, 600, 900, Ve 1500. For EN/DIN standards, pressure ratings are shown as PN10, PN16, PN40, vesaire.

3. Dış Çap (İLE İLGİLİ)

The total diameter of the flange face, important for proper alignment with mating components.

4. Cıvata Daire Çapı (BCD veya PCD)

The diameter of the circle passing through the center of each bolt hole.

5. Number and Size of Bolt Holes

Bolt quantity and diameter must match exactly to ensure tight, leak-free assembly.

6. Flanş Kalınlığı

Measured from face to back, thickness affects strength and gasket compression.

7. Bore or Inner Diameter

Should match the outside diameter of the connecting pipe to maintain flow continuity.

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How to Determine the Correct Flange Size

Follow these steps to ensure you choose the correct flange size

Adım 1: Identify the Pipe Size

Check the nominal pipe size (NPS veya DN). If you’re replacing an existing flange, measure the inside diameter and wall thickness of the pipe it connects to.

Adım 2: Confirm the Pressure Rating

Refer to the piping system design or operating conditions. If the system operates under high pressure or temperature, a higher class (örneğin, Sınıf 300 or PN40) gereklidir.

Adım 3: Measure the Flange Dimensions

Use calipers or a measuring tape to determine

• Dış çap

• Cıvata daire çapı

• Number and size of bolt holes

• Bore and thickness

Compare your measurements with a standard flange dimension chart (örneğin ASME B16.5 veya TR 1092-1) to verify the size.

Adım 4: Check the Flange Type and Face

Is it a weld neck, bağcıksız, kör, soket kaynağı, or threaded flange Is it raised face, düz yüz, or ring-type joint This affects both installation and gasket compatibility.

Adım 5: Confirm Standards and Material

Ensure the flange material (örneğin, paslanmaz çelik, karbon çeliği, alaşımlı çelik) and manufacturing standard match your system requirements.

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Flange Size Chart Example (ASME B16.5, Sınıf 150, NPS'ler 4)