JIS B 8211 Gauge Glass – Borosilicate Flat Sight Glass for Boiler Water Level Indicators
The JIS B 8211 gauge glass is a flat borosilicate sight glass used to monitor water levels in boiler drums, high-pressure vessels, and liquid storage tanks. It offers strong thermal shock resistance, clear visibility, and a stable sealing surface for standard JIS gauge assemblies.
Function and Applications
This gauge glass is installed in a metal gauge body on steam boilers, feedwater tanks, deaerators, and process vessels. It serves as the transparent window in water level indicators and is a direct replacement part for JIS standard gauge assemblies.
- Boiler water level gauge glass
- High pressure transparent level gauge glass
- Flat sight glass for steam and hot water systems
- JIS B 8211 gauge glass replacement for boiler drums
Material and Specifications
- Material: borosilicate glass 3.3
- Standard: JIS B 8211
- Type: flat transparent gauge glass
- Surface: polished smooth, edges chamfered
- Thermal expansion coefficient: about 3.3 × 10⁻⁶ K⁻¹
Advantages
- High resistance to thermal shock in steam and high-temperature water service
- Clear view for accurate liquid level reading
- Flat surface and stable dimensions allow reliable sealing with standard gauge gaskets
- Available in common lengths from 200 mm to 350 mm
- Each batch is checked for dimension accuracy and surface defects before packing
Technical Data
| Parameter | Value |
|---|---|
| Standard | JIS B 8211 |
| Material | Borosilicate glass 3.3 |
| Type | Flat transparent gauge glass |
| Width | 34 mm |
| Thickness | 17 mm |
| Available lengths | 200, 250, 300, 350 mm |
| Working pressure | Depends on gauge body rating and installation length |
| Working temperature | Suitable for high-temperature boiler service; verify according to installation conditions |
Common Sizes
| Length (mm) | Width (mm) | Thickness (mm) |
|---|---|---|
| 200 | 34 | 17 |
| 250 | 34 | 17 |
| 300 | 34 | 17 |
| 350 | 34 | 17 |
Other lengths and width options can be supplied on request.
Quality Inspection and Examples
Dimensional inspection report: Each batch is measured for length, width, thickness, and edge chamfer before packing. Records are kept for every production lot.
Surface quality check: Every glass piece is inspected under light for scratches, bubbles, chips, and flatness deviations.
Customer example: A boiler maintenance supplier uses 250 mm and 300 mm JIS B 8211 gauge glasses in standard water level gauges. The current batch showed stable sealing and no breakage in normal operation.
Test data: Thermal shock and pressure resistance are verified according to standard test procedures. Test reports and material certificates are available on request.
