To prevent water theft, the choice of dial material is very important. The anti-theft water meter dial cover is divided into plastic and glass, and the two kinds of water meters that seem to be similar in appearance are very different in the performance of anti-theft water.
The plastic dial cover material is light, low-cost, and easily damaged.
The glass dial cover of the water meter is effectively resistant to tampering. and more durable.
But which glass is better for a water meter? And how exactly does it prevent water tampering?
Let me conduct a comprehensive analysis from the material performance, tampering methods, and the anti-theft scheme, and you will uncover the secrets of the anti-theft water meter dial.
Plastic Water Meter Dial
Plastic material: Plexiglass -PC polycarbonate, PMMA polymethyl methacrylate
特徴： The Plastic water meter dial must use high transparency plastic to see the reading of the water meter.
PMMA, as the most transparent plastic, is widely used in lamps and lanterns, so it is also fully capable of being used on water meters.
PC material is very widely used, but also has a high light transmittance, the price is cheaper than PMMA, and the impact strength is higher than PMMA.
PC material is the most common material for water meter plastic dial, with the highest comprehensive cost performance.
Disadvantages: But all plastic, even after special treatment of PMMA and PC, still fall short of tempered glass water meter in terms of its high temperature resistance and impact resistance, anti-ultraviolet capabilities. Moreover, they do not offer anti-theft functionality.
Glass Water Meter Dial
Glass material: Inorganic glass – high borosilicate glass, tempered glass
Glass water meter dial is a better choice of water meter material. But not regular glass.
Ordinary glass has low strength and is easy to break. Poor thermal stability, drastic temperature changes will lead to glass breakage. Low hardness level, the surface is easily scratched.
Borosilicate Glass Water Meter Dial
Glass with a high boron content, due to differences in its molecular structure:
Advantages:
- The thermal stability is very high, and the linear thermal expansion coefficient is (3.3±0.1)×10⁻⁶/K, which is about one third of ordinary glass. High borosilicate glass will not cause the glass to break when the temperature changes dramatically.
- High surface hardness, strong scratch resistance.
Tempered Glass Water Meter Dial
Tempered glass is produced by subjecting ordinary glass to heat treatment.
Advantages:
- Tempered glass’s impact resistance is 3 to 4 times that of regular glass.
- The bending strength of tempered glass is 4 to 5 times that of regular glass.
- Thermal stability can reach up to 300°C(572℉).
| Performance Indicator | Borosilicate Glass | Tempered Glass |
|---|---|---|
| Main Composition | Silica (SiO₂: 80–85%), Boron Oxide (B₂O₃: 12–15%) | Ordinary soda-lime glass (SiO₂: 70–75%), physically/chemically strengthened |
| Manufacturing Process | High-temperature melting (>1600°C) forming, low expansion coefficient formula | Ordinary glass heated to 620°C and rapidly cooled (physical tempering) |
| Hardness (Mohs Scale) | 6.5–7.0 (close to quartz) | 5.5–6.0 (surface compressive stress layer improves scratch resistance) |
| Impact Resistance | Weak (prone to shattering under direct mechanical impact) | Very strong (impact strength is 4–5 times that of ordinary glass) |
| Thermal Shock Resistance | Very strong (can withstand ΔT ≥ 300°C, e.g., heated to 500°C and cooled with ice water without cracking) | Weak (ΔT ≤ 150°C; prone to spontaneous breakage under sudden temperature changes) |
| Maximum Service Temperature | Long-term: 450°C Instantaneous: 800°C | Long-term: 280°C Instantaneous: 300°C |
| Fracture Morphology | Fine cracks, large and sharp fragments | Breaks into uniform small granules with dulled edges (characteristic of safety glass) |
| Typical Applications | Laboratory glassware, high-temperature lighting, fireplace windows, aerospace glass | Architectural glass, car side windows, furniture countertops, smartphone screens |
Through the table, the performance of borosilicate glass and tempered glass can be intuitively compared.
To achieve anti-theft water functionality for water meters, which material should be used for the water meter dial?
We need to analyze the problem based on the methods of water theft.
Methods of Water Theft via the Water Meter Dial:
- Break the Water Meter Dial:
The thieves will use tools such as a hammer, screwdriver, or a stone with sharp corners to smash the dial and then clamp the main gear to prevent the digital wheel from turning. By the time the meter reader of the water meter company found out, a lot of water bills had been lost.
- Piercing the Water Meter Dial with a Needle:
The thieves heat the steel needle and insert it at the dial above the gear, blocking the main gear and preventing the digital wheel from turning. Once the needle is removed, if the meter reader does not look carefully, it may not be able to tell that the dial has been destroyed.
We can see the Key Factors for Anti-Theft Water Meter Dials:
- Impact Resistance
- Temperature Resistance
Impact Resistance
Tempered Glass:
Tempered glass has the strongest impact resistance. Its bending strength is 4–5 times that of ordinary glass, and its impact strength is 3–4 times higher. Even if struck forcefully with a hammer, it will not break.
Borosilicate Glass:
Borosilicate glass has impact resistance similar to that of ordinary glass, which is relatively average.
Temperature Resistance
Borosilicate Glass:
Borosilicate glass performs best in high-temperature environments. It can be used continuously at 450°C and can withstand instantaneous heating to 300°C without cracking.
Tempered Glass:
Tempered glass can be used continuously at 280°C and can withstand instantaneous heating to 150°C without cracking.
| Destruction Method | Smashing the Water Meter Dial | Piercing the Water Meter Dial |
|---|---|---|
| Tempered Glass | Strongest | 強い |
| High Borosilicate Glass | 弱い | Strongest |
Tempered glass is the best material choice for the water meter dial.
Other Advantages of Tempered Glass Dial
In addition to the advantages of anti-theft water, the glass dial water meter has three significant advantages.
- Achieves IP68 Waterproof:
Can reach IP68 waterproof and dustproof grade, IP68 Water Meter. - Stronger UV Resistance:
Anti-ultraviolet (UV) performance is stronger, the plastic material can add anti-UV material to improve the anti-ultraviolet ability. But with time, there will still yellow, brittle phenomenon. While glass will not, glass water meters are more suitable for outdoor installation and use in direct sunlight. - Longer Service Life:
Service life, the service life of the glass water meter is generally more than 15 years, and the life of the plastic water meter is about 10 years.
BMAG Tempered Glass Dial Water Meters: The Best Choice
BMAG’s tempered glass dial water meters use high-quality tempered glass, making them durable and reliable. Combined with high measurement accuracy, they are the best choice for water metering needs.
Additionally, we can offer water meters with a 45° tilted tempered glass dial, it’s a high complex manufacturing process and significant production challenges. Few factories can produce this type of meter, it is one of our star products.
Welcome to inquire! Free samples are available.
