会社のニュース The brief introduction of Sight Glass

The brief introduction of Sight Glass

A sight glass is a transparent window glass designed for use under specific temperature and pressure conditions. It is typically manufactured from high-quality heat-resistant glass through specialized processes, characterized by high transparency, heat resistance, pressure resistance, and excellent chemical stability.

Abstract
Sight glass is specialized equipment used to observe the flow of liquids, gases, steam, and other media. Primarily employed for monitoring production processes, it is an essential component in chemical plants, metallurgy facilities, steel mills, pipelines, and similar industrial settings.

Basic Properties

• Softening Temperature: 820°C – 1750°C

• Light Transmittance: 80% – 95%

• Chemical Stability:

  • Water Resistance: Grade 1

  • Acid Resistance: Grade 1

  • Alkali Resistance: Grade 2

Classification

Industrial sight glass is categorized into three main types based on performance:

1. High-Temperature Resistant Sight Glass

   • Withstands extreme temperatures without cracking. Ideal for high-temperature observation windows.

   • Properties:

     • Operating Temperature: 350°C – 1500°C

     • Thermal Shock Resistance: 180°C – 1100°C

     • Bending Strength: 80–220 MPa

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2. High-Pressure Resistant Sight Glass

   • Features high compressive/bending strength and mechanical stability. Designed for high-pressure vessels.

   • Properties:

     • Compressive Strength: Suitable for 1–30 MPa environments

     • Bending Strength: 100–220 MPa

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3. High-Temperature & High-Pressure Resistant Sight Glass

   • Combines pressure tolerance with exceptional thermal shock resistance (no cracking under rapid temperature changes).

   • Properties:

     • Max. Temperature: Up to 1500°C

     • Thermal Expansion Coefficient: 1/12–1/20 of ordinary glass

Dimensions

• Round Sight Glass: Ø10–700 mm

• Rectangular Sight Glass: 10×10–750×1200 mm

• Thickness: Standard 1.5–20 mm; Customizable up to 50 mm.

Standard Specifications

Common sizes (diameter × thickness ± tolerance):

Applications

Widely used in pressure vessels and instrumentation across industries, including:

• Oil & Gas: Pipelines, valves

• Chemical: Reactors, storage tanks

• Pharmaceutical: Process monitoring

• Industrial Equipment: Cracking furnaces, boilers, pressure chambers