Hebei Xukang Meter Manufacturing Co., Ltd. It is a highly specialized production: Circular Borosilicate Glass For Sight Glass,microcrystalline glass, high temperature resistant, resistant to high pressure glass, explosion-proof glass, high pressure liquid level gauge glass, glass, one-way perspective 7-14 um ir, UV ultraviolet glass, filter, complete sets of sight glass, high temperature resistant sealant, mica seals manufacturer,And through ISO9001:2008 quality system certification.

Our company has a large number of domestic leading level of grinding, polishing, plating, hot bending, vacuum laminating, high-speed engraving, laser cutting, ultra-high pressure water cutting, precision automatic grinding machine, tempered furnace, impact testing machine, pressure testing machine and other advanced processing equipment and high-tech testing equipment, military quality, civilian price, gaining the hair, are invincible!

Fist product "far infrared window glass used for pressure vessels, high pressure liquid level meter aluminum silicon glass, glass lens, explosion-proof glass, high borosilicate glass, quartz glass lens", such as a large number of standardization, seriation of high-end products are widely used in the domestic each big laboratory, electric power, metallurgy, communications, geological exploration, pressure containers, ships, nuclear power plants, petrochemical, mining equipment and other high-end industry system!

High pressure liquid level gauge glass is introduced: specifications:
Standards: 891-2001 "high pressure liquid level gauge glass" main ingredients: alumina (15%), silica (58%) and so on bending strength: 220 Mpa or greater, the compressive performance: 16 Mpa and 22.5 Mpa main use: nuclear power-stations boiler steam package such as high pressure water level gauge, deep sea exploration equipment, high pressure oil facilities, such as supercritical fluid extraction device observation window.

Material	Borosilicate, Aluminosilicon
Heat stability	≤300 ℃
Heat-resistant temperature	≤500 ℃
Working pressure	the maximum working pressure ≤ 22.5 MPa

How to Distinguish the Quality of Sight Glass

1. Raw Material Grade

Borosilicate 3.3 sight glass (High quality)

Low thermal expansion coefficient, outstanding thermal shock resistance, withstand sudden hot and cold alternation; resistant to weak acid and weak alkali, clear light transmission. Suitable for steam vessels, high-temperature reactors and steam jacketed sight glasses.
Ordinary soda-lime glass (Low quality)

Poor temperature resistance, easy to crack under temperature fluctuation; low corrosion resistance, prone to fogging and surface corrosion when contacting chemical medium. Only for normal-temperature clean water pipelines.
Mica composite sight glass (Premium high-pressure grade)

Laminated mica sheet with borosilicate glass, anti-impact, high-pressure resistant, exclusively for high-pressure boilers and hydrogenation equipment.

2. Surface Inspection Standard

High-quality sight glass

Smooth, scratch-free surface without bubbles, stones, stripes and blisters inside the glass body.
Uniform thickness, flat and parallel two sides; no warping or deformation.
Clean edge cutting, chamfered smoothly without tiny cracks or chipping (edge microcracks cause easy breakage under pressure).

Inferior sight glass

Visible air bubbles, impurities and linear stripes inside, affecting observation.
Rough cutting edges with burrs and micro cracks; uneven thickness leads to stress concentration.
Obvious scratches on the surface, easy to accumulate dirt and hard to clean.

3. Pressure & Temperature Resistance Test

High-quality product

Clear marked nominal pressure (PN16/PN40/PN100) and temperature range (-30℃ ~ 350℃); pass factory hydraulic pressure test and thermal shock test. No leakage or cracking after repeated cold-heat cycle tests.

Inferior product

No standard parameter marking; cannot bear rated pressure, crack easily when pressure rises slightly. Break quickly under alternating hot and cold medium.

4. Light Transmittance & Observation Effect

Premium glass features high light transmittance, no color cast, clear view of internal medium flow and liquid level.

Low-grade glass appears yellowish or foggy, low light penetration, blurry observation, cannot distinguish liquid-gas boundary clearly.

5. Anti-corrosion Performance

High borosilicate glass forms stable anti-corrosion layer, not easy to be eroded by chemical liquid for long-term use.

Cheap glass will generate white corrosion spots after long contact with acid-base medium, losing transparency rapidly.

Brief Summary

Judge sight glass quality by five dimensions: glass material type, surface finish, edge processing, pressure & temperature resistance, light transmittance and anti-corrosion property. Borosilicate 3.3 and mica laminated glass are top-tier choices for industrial harsh working conditions.

Circular Borosilicate Glass For Sight Glass