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

الشفاه هي مكونات أساسية في أنظمة الأنابيب, تعمل كموصلات ميكانيكية تضمن الأمان, مانعة للتسرب, والمفاصل الصالحة للخدمة بين الأنابيب, الصمامات, مضخات, والمعدات. But with so many standards, تقييمات الضغط, and sizes available, one key question arises — how to know the correct flange size

في هذه المقالة, ساسا مستطيل 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

في ساسا مستطيل, we support customers in choosing flange dimensions that comply with global standards such as ASME, EN, DIN, و جيس.

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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. حجم الأنبوب الاسمي (مصادر القدرة النووية) أو الاسم المميز

This refers to the size of the pipe the flange is intended to connect. في أمريكا الشمالية, مصادر القدرة النووية (in inches) يستخدم. In Europe and other regions, الاسم المميز (diameter nominal in mm) applies.

2. تصنيف الضغط (Class or PN)

Defines the maximum pressure a flange can withstand. Common ASME classes are 150, 300, 600, 900, و 1500. For EN/DIN standards, pressure ratings are shown as PN10, PN16, بي إن 40, إلخ.

3. القطر الخارجي (ل)

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

4. قطر دائرة الترباس (BCD or 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. سمك شفة

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

خطوة 1: Identify the Pipe Size

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

خطوة 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 (على سبيل المثال, فصل 300 or PN40) مطلوب.

خطوة 3: Measure the Flange Dimensions

Use calipers or a measuring tape to determine

• القطر الخارجي

• قطر دائرة الترباس

• عدد وحجم فتحات الترباس

• Bore and thickness

Compare your measurements with a standard flange dimension chart (مثل ASME B16.5 أو إن 1092-1) to verify the size.

خطوة 4: Check the Flange Type and Face

Is it a weld neck, سهل الارتداء, أعمى, لحام المقبس, or threaded flange Is it raised face, وجه مسطح, or ring-type joint This affects both installation and gasket compatibility.

خطوة 5: Confirm Standards and Material

Ensure the flange material (على سبيل المثال, الفولاذ المقاوم للصدأ, الصلب الكربوني, سبائك الصلب) and manufacturing standard match your system requirements.

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Flange Size Chart Example (ASME B16.5, فصل 150, مصادر القدرة النووية 4)