Overview
Red Line & Transparent Level Gauge Glass Sight Glass Tube is a sight / viewing glass made from Borosilicate Glass 3.3. Listed geometry: size Od From 6mm to 300mm. Optical / electrical data: transmittance ≥92%, sheet resistance ΔT ≤ 180ºC. Temperature -20ºC ~ +280ºC. Dimensions, material grade, coating and finish can be quoted to your drawing; the values above are the listed starting point.
Specifications
| Material | Borosilicate Glass 3.3 |
|---|---|
| Size | Od From 6mm to 300mm |
| Transmittance | ≥92% |
| Item | Tubular Level Gauge Glass Sight Glass Tube |
| Process | Cut, Polish, Ground, Tempered,Printing |
| Property 1 | Borosilicate Heat Resistant |
| Shipment | by Sea, by Air, by Courier |
| Clear plain tubular gauge glass | Full transparent wall, suitable for clean, colored liquid observation. |
| Red line sight gauge glass | Built-in distinct red longitudinal indicator line, clearer liquid level dividing line under low light, standard choice for boiler water level monitoring. |
| Working Temperature | -20ºC ~ +280ºC |
| Thermal Shock Resistance | ΔT ≤ 180ºC |
| Working Pressure | ≤1.6MPa (custom high-pressure tube available) |
| Styles | Clear transparent tube / Single red line indicator tube |
| Size Range | OD 6mm~50mm, customizable ID & full length as drawings |
| Surface | Bubble-free, scratch-free, smooth cut ends |
| Support OEM & ODM | Custom diameter, length, red line position, end grinding processing |
| Strict 3-layer inspection before delivery | Size tolerance, internal defects, temperature resistance test |
| Safe export packaging | Individual foam tube + carton, anti-breakage for sea & air shipment |
| Packaging | Separated EPE foam tube packaging, hard export carton, shockproof anti-crack protection |
| Temperature resistance | Long working temperature ≤ 450 ° C, short time working ≤ 500 ° C |
| Light transmission rate | 95% up |
| Hydraulic Water-resistant strength | More than test 40Kgf/cm ² |
| Thermal stability | T300 ° C |
| Linear expansion coefficient (0-300 ° C) | 3.3 × 10-7 K-1 |
| Softening temperature | 820° C |
| Supplier | Jinan Honhai Glass Company Limited |
What to specify when you request a quote
- Glass type and thickness — listed as “Borosilicate Glass 3.3”; name the glass and thickness.
- Temperature and pressure — listed as “-20ºC ~ +280ºC”; give working temperature, thermal shock and any pressure rating.
- Strengthening and safety — listed as “More than test 40Kgf/cm ²”; state tempering, lamination or the safety standard.
- Outline and edges — listed as “Od From 6mm to 300mm”; send a drawing with outline, holes and edge finish.
Engineering guides for this part
For material grades and coating options, see Infrared Window Glass: Material Options for Optical Sensors & Parts. How parts like this are machined and finished is covered in Precision Bore Glass Tubing Processing: End-to-End Manufacturing for Industrial Buyers. For an application example, read Quartz Glass Windows for High-Temperature Appliance Modules. Before sending a drawing, check Thermal Conductivity of Quartz Glass & Fused Quartz: A Process Guide. A related standard product is AR Anti-Reflection Optical Window.
