# Borosilicate 3.3 Flow Sight Glass Tube for Pipeline Flow Indicator

> Borosilicate 3.3 Flow Sight Glass Tube for Pipeline Flow Indicator — a sight / viewing glass: Borosilicate Glass. Specs, RFQ checklist and custom sizes to…

- Page: https://machiningglass.com/products/borosilicate-3-3-flow-sight-glass-tube-for-pipeline-flow-indicator/
- SKU: MG-6C762B
- Category: Industrial, Architectural & Appliance Glass > Sight Glass & Industrial Viewing Windows
- Image: https://machiningglass.com/wp-content/uploads/2026/10/Borosilicate-3-3-Flow-Sight-Glass-Tube-for-Pipeline-Flow-Indicator.webp
- Updated: 2026-10-24

Product type: Glass Tube. Application: Daily Use. Model: HHLF.

## Overview

Borosilicate 3.3 Flow Sight Glass Tube for Pipeline Flow Indicator is a sight / viewing glass made from Borosilicate Glass. Listed geometry: size : 3/8", 7/16" 1/2", 9/16", 5/8", 11/16", 3/4", 7/8. Optical / electrical data: transmittance ≥92%, sheet resistance 300ºC instant temperature difference. Temperature -20℃~80℃. Listed for Daily Use applications. Dimensions, material grade, coating and finish can be quoted to your drawing; the values above are the listed starting point.

## Specifications

| Parameter | Value |
| --- | --- |
| Material | Borosilicate Glass |
| Type | Glass Tube |
| Size | : 3/8", 7/16" 1/2", 9/16", 5/8", 11/16", 3/4", 7/8 |
| Application | Daily Use |
| Model NO. | HHLF |
| Glass Type | Hollow Glass |
| Principle | Vibration Sensor |
| Range | 0-3m |
| Measurement Accuracy | ±3mm |
| Accuracy | 0.1% |
| Kind | Liquid Level Transmitter |
| Process Temperature | -20℃~80℃ |
| Name | Clear Flow Sight Glass Tube |
| Decoration | Red Lines |
| Wall Thickness | Heavy Wall and Super Heavy Wall |
| Special | High Precision and Straightness |
| Color | Transparent |
| Working temperature range | -60ºC ~ 450ºC; withstand 300ºC instantaneous temperature difference without breakage. |
| Thermal expansion coefficient | 3.3×10/K |
| Operating temperature | -60ºC ~ 450ºC |
| Max thermal shock resistance | 300ºC instant temperature difference |
| Light transmittance | ≥92% |
| Tolerance | OD ±0.1mm, Length ±1mm |
| Pressure range | Low & medium pressure |
| Certifications | ISO9001, RoHS compliant |
| Supplier | Jinan Honhai Glass Company Limited |

## What to specify when you request a quote

- **Glass type and thickness** — listed as “Borosilicate Glass”; name the glass and thickness.
- **Temperature and pressure** — listed as “-20℃~80℃”; give working temperature, thermal shock and any pressure rating.
- **Strengthening and safety** — state tempering, lamination or the safety standard.
- **Outline and edges** — listed as “: 3/8", 7/16" 1/2", 9/16", 5/8", 11/16", 3/4", 7/8”; send a drawing with outline, holes and edge finish.

## Engineering guides for this part

For material grades and coating options, see [Optical Glass Material Options for Precision Filters and Windows](https://machiningglass.com/materials/optical-glass-material-options-for-precision-filters-and-windows/). How parts like this are machined and finished is covered in [Precision Bore Glass Tubing Processing: End-to-End Manufacturing for Industrial Buyers](https://machiningglass.com/capabilities/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](https://machiningglass.com/applications/quartz-glass-windows-for-high-temperature-appliance-modules/). Before sending a drawing, check [Quartz Glass Manufacturing: Controlling Thermal Conductivity in Fused Silica](https://machiningglass.com/resources/quartz-glass-manufacturing-controlling-thermal-conductivity-in-fused-silica/). A related standard product is [AR Anti-Reflection Optical Window](https://machiningglass.com/products/ar-anti-reflection-optical-window/).

## FAQ

### What is the Borosilicate 3.3 Flow Sight Glass Tube for Pipeline Flow Indicator made of?

It is listed as Borosilicate Glass. Other grades can be quoted if your application needs different transmission, thermal or chemical properties.

### What sizes and thicknesses are available?

The listing gives size : 3/8", 7/16" 1/2", 9/16", 5/8", 11/16", 3/4", 7/8. Custom outlines and thicknesses are made to drawing; state the tolerance you need.

### What optical or electrical performance does it have?

Listed values: transmittance ≥92%, sheet resistance 300ºC instant temperature difference. Confirm the values at your operating wavelength, angle and temperature when you request a quote.

### Where is this sight / viewing glass used?

Listed applications: Daily Use.

### What should I include in a quote request?

Include glass type and thickness, temperature and pressure, strengthening and safety and outline and edges, plus quantity and a drawing if the part is custom.

## Request a quote

Send drawings, tolerances and quantity: https://machiningglass.com/contact/?rfq_product_id=19687#mg-rfq

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Source: Custom Precision Glass Machining — https://machiningglass.com/