DN20 Rotary Water Meter (20mm Caliber)A mechanical velocity-type water meter primarily designed for small-flow residential and commercial water measurement. Its working principle is based on water flow driving the impeller (rotor) to rotate, with the rotation count converted into water consumption (cubic meters/m³) through a gear transmission mechanism. It features simple structure, stable metering accuracy, and low cost.
High Accuracy: minimal error, stable performance.
Pressure Resistance: Withstands ≥1.0 MPa, suitable for standard pipelines.
Easy Installation: Threaded connections (G3/4″ or BSP), fits household pipes.
Cost-Effective: No power needed, maintenance-free, service life ≥6 years (regular verification required).
Key Technical Parameters
Parameter Value/Description
Nominal Diameter (DN) 20mm
Permanent Flow (Q₃) 4.0m³/h
Transitional Flow (Q₂) 0.08 m³/h
Minimum Flow (Q₁) 0.0512 m³/h
Overload Flow (Q₄) 5 m³/h
Accuracy Class Class 2 (±2% high flow, ±5% low flow)
Max. Working Pressure 1.0 MPa (standard)
Temperature Range Cold water meter: 0.1–30°C; Hot water meter (Requires special marking): 30–90°C
Pressure Loss ≤0.063 MPa (at Q₃)
Structure & Working Principle
Components:
Body: Brass alloy or engineering plastic (potable water compliant).
Impeller (Rotor): Rotates proportionally to flow rate.
Gear Transmission: Converts rotations to mechanical counts.
Register: Displays cumulative volume (mechanical dial/pointer).
Principle: Water flow drives the impeller, whose rotation is transmitted via magnetic coupling/gears to the counter.
Features
High Accuracy: minimal error, stable performance.
Pressure Resistance: Withstands ≥1.0 MPa, suitable for standard pipelines.
Easy Installation: Threaded connections (G3/4″ or BSP), fits household pipes.
Cost-Effective: No power needed, maintenance-free, service life ≥6 years (regular verification required).
Applications
Households: Apartments, residential water supply.
Commercial: Shops, offices, schools with low flow demand.
Public Facilities: Restrooms, drinking fountains.
Installation & Maintenance
Orientation: Mount horizontally, register facing up; arrow aligns with flow direction.
Straight Pipes: Upstream ≥10×DN (15cm), downstream ≥5×DN (7.5cm); avoid elbows/valves near meter.
Protection: Insulate in freezing conditions; shield from vibration/magnetic fields (e.g., motors).
Flow Parameters
| Nominal Diameter (DN) | Permanent Flow (Q₃) (m³/h) | Transitional Flow (Q₂) (m³/h) | Minimum Flow (Q₁) (m³/h) | Overload Flow (Q₄) (m³/h) | Metering Class | Typical Applications |
| DN15 | 2.5 | 0.05 | 0.03125 | 3.125 | Class 2 | Residential households,
low-flow water supply |
| DN20 | 4.0 | 0.08 | 0.05 | 5.0 | Class 2 | Homes or small shops |
| DN25 | 6.3 | 0.126 | 0.078 | 7.87 | Class 2 | Small/medium commercial, apartments |
| DN32 | 10 | 0.2 | 0.125 | 12.5 | Class 2 | Medium-sized buildings, public facilities |
| DN40 | 16 | 0.32 | 0.20 | 20 | Class 2 | Large residences, small factories |
| DN50 | 25 | 0.5 | 0.3125 | 31.25 | Class 2 | Industrial, commercial complexes |
| DN65 | 40 | 0.8 | 0.50 | 50 | Class 2 | Large-scale industrial, municipal water supply
|
Address: Xiao'anzi Industrial Park, Baishabu Town, Lanshan District, Linyi City, Shandong Province
Call us now:+861556294599
Email: ivy@sdchenshuo.cn
Shandong Chenshuo Instrument Co., Ltd.
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