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Technical Specifications
| Diameters | DN15, DN25, DN50, DN80, DN100, DN150 (For other diameters, please consult with the manufacturer) |
| Flow Range | Liquid: 1.0~150000 L/h (See the flow rate table for details on the flow rate range) |
| Gas: 0.05~3000 m³/h | |
| Range Ratio | 10:1, 20:1 (Special) |
| Accuracy | Level 1.5, Level 1.0 (Special) |
| Pressure Level | DN15, DN25, DN50: 4.0MPa (Maximum 20MPa) |
| DN80, DN100, DN150: 1.6MPa (Maximum: DN80: 10MPa; DN100: 6.4MPa; DN150: 4.0MPa) | |
| Medium Temperature | Standard: -30°C to +120°C |
| High temperature: 120°C to 350°C (PTFE lining must not exceed 80°C) | |
| Power Supply | 24VDC (12-36VDC), lithium battery powered, 220VAC |
| Output Signal | Two-wire system: 4~20mA DC, 4~20mA DC + HART protocol |
| Three-wire system: MODBUS (RTU mode); cumulative pulse (24V, 50% duty cycle) | |
| Optional relay alarm, contact capacity: 250V AC 3A | |
| Output Load | 5009 (when powered by 24V) |
| Ambient Temperature | Local type: -40~120°C |
| Remote transmission type: -30°C~60°C | |
| Storage Conditions | Temperature: -40°C to 85°C |
| Humidity: ≤ 85% | |
| Connection Method | Standard type: Flange standard GB/T9119-2000, user-specified options available |
| Food type: Clamp connection method | |
| Special type: Designed according to user requirements | |
| Cable Interface | M20x1.5, 1/2NPT |
| Enclosure Protection | IP65 |
| Medium Viscosity | DN15: η < 5mPa·s |
| DN25: η < 250mPa·s | |
| DN50 ~ DN150: η < 300mPa·s | |
| Measuring Tube Material | R: 304 (Equivalent to 0Cr18Ni9) |
| Ro: 316Ti (Equivalent to 0Cr18Ni12Mo2Ti) | |
| Float Material | RL: 316L, 00Cr17Ni4Mo2 |
| H: Hastelloy B, Hastelloy C | |
| Ti: Titanium, titanium alloy | |
| Rp: PTFE Lining (Polytetrafluoroethylene) | |
| Hygienic Surface Finish | < 0.8Ra (Ra, arithmetic mean deviation of the profile; applicable to hygienic-grade rotameter components in contact with medium) |
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Applications
The FK-LZ-B Metal Tube Rotameter is widely used in industrial process flow measurement, including:
Petrochemical Industry
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Chemical liquid flow measurement
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Gas and steam flow monitoring
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Process control systems
Power & Energy Industry
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Boiler steam flow measurement
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Cooling water monitoring
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Auxiliary gas systems
Metallurgy & Steel Industry
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Industrial gas measurement
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Cooling and lubrication systems
Food & Beverage Industry
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Liquid ingredient flow monitoring
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Utility gas measurement
Pharmaceutical Industry
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Process liquid control
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Gas supply systems
Water Treatment
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Chemical dosing measurement
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Treated water and wastewater monitoring
Its ability to measure liquid, gas and steam makes it a versatile solution for industrial automation systems.
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Why Choose This Metal Tube Rotameter
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Proven variable area flow measurement technology
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Suitable for harsh industrial environments
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Excellent performance-price ratio
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Easy installation and low maintenance
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Reliable solution for low flow measurement
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Measuring principle
The FK-LZ-B operates based on the variable area flow measurement principle.
Inside a vertical conical measuring tube, a movable float is installed. When fluid flows upward through the tapered tube:
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The float rises due to fluid force.
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The float position increases with increasing flow rate.
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The annular area between the float and cone tube changes accordingly.
When the flow rate reaches a constant value (Q), the float remains in dynamic equilibrium at a certain height (h). At this point:
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The weight of the float (G)
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The buoyancy force (F)
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The fluid force (P)
reach equilibrium.
According to Bernoulli’s equation, force balance principles, and fluid continuity laws, the instantaneous flow rate can be calculated from the annular area between the float and the cone tube.
Inside the float, a high-performance permanent magnet is embedded. The magnetic field allows the float position to be transmitted to the external indicator through non-contact magnetic coupling.
The indicator converts the float displacement into:
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Dial display indication
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Digital LCD display
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Standard 4–20mA output signal
