Krohne Variable area flowmeters DK32
The DK32 is a variable area (VA) flowmeter from KROHNE, specifically engineered for measuring very low flow rates of liquids and gases. It is particularly suitable for flow monitoring and dosing in gas analyzer systems and on purge panels, thanks to its robust all-metal design and compact construction. The meter is available with an integrated metering valve as standard, enabling precise flow setting directly at the device.
Key Features and Benefits
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Optimized for Low Flows: Designed for small flow rates typically found in 4 to 12 mm (1/8 to 1/2″) pipelines. Full scale values range from 1.6 to 150 l/h for liquids and 16 to 4,800 l/h for gases, with a turndown ratio of 10:1.
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Simple, Low-Cost Installation: The meter measures and displays flow without requiring an auxiliary power supply. Straight inlet and outlet runs are unnecessary, simplifying integration into existing systems.
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Sturdy All-Metal Construction: Available in stainless steel or alloy, the DK32 withstands difficult process conditions with temperatures up to +200°C (+392°F) and pressures up to 220 barg (3190 psig).
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Integrated Metering Valve: A standard needle valve enables precise flow regulation directly at the measuring point, saving on additional valve installation.
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Optional Electrical Output: The DK32/ESK3x variant offers a two-wire 4…20 mA output with HART 7 communication, enabling continuous monitoring, logging, or control of low-flow applications.
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Functional Safety: Suitable for use in Safety Instrumented Systems with SIL 2 capability. In redundant design (1oo2), it can also be used in SIL 3 applications (type A device).
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Hazardous Area Approvals: Approved for use in hazardous areas with ATEX, IECEx, FM, and NEPSI certifications.
Technical Specifications (at a Glance)
| Specification | Detail |
|---|---|
| Measuring Principle | Float-type variable area |
| Full Scale (Liquids) | 1.6…150 l/h (0.4…40 GPH) |
| Full Scale (Gases) | 16…4,800 l/h (0.6…170 SCFH) |
| Accuracy | ±4% of measured value (per VDI/VDE 3513-2) or ±3% of full scale |
| Turndown Ratio | 10:1 |
| Process Temperature | –40…+200 °C (–40…+392 °F) |
| Process Pressure | Max. 220 barg (3190 psig) |
| Process Connection | G¼, ¼ NPT internal thread; other connections available |
| Wetted Materials | Stainless steel or alloy |
| Communication | 4…20 mA / HART 7 (DK32/ESK3x variant) |
| Ingress Protection | IP65/66 |
| Ex Approvals | ATEX, IECEx, FM, NEPSI |
The DK32 provides a cost-effective, reliable solution for low-flow measurement in analyzer systems, purge panels, and dosing applications, combining robust construction, integrated flow regulation, and optional digital communication in a compact package.
Krohne Variable area flowmeters DK32
The DK32 is a variable area flowmeter from KROHNE, designed for measuring low flow rates of liquids and gases. The tried and tested meter is particularly suitable for flow monitoring and dosing in gas analyzer systems or on purge panels. Due to its robust all-metal design, it can also be used in difficult process conditions with temperatures up to +200°C (+392°F) or pressures up to 400 barg (5800 psig) depending on configuration.
The flowmeter operates on the float measuring principle. Fluid flows through a tapered measuring tube, lifting a float until equilibrium is reached between the upward force of the flow and the downward force of the float’s weight. The float’s position, which corresponds to the flow rate, is magnetically transmitted to a mechanical indicator for local display without requiring any power supply.
The DK32 is available in several configurations to suit different application needs. The DK32 base model provides local mechanical indication only, with no auxiliary power required. The DK32/K variant adds one or two limit switches for MIN/MAX flow monitoring, enabling alarm or control functions. The DK32/ESK3x variant introduces a two-wire 4…20 mA current output with HART 7 communication, allowing continuous transmission of flow values to a process control system for monitoring, logging, or control purposes.
The meter features an integrated metering valve as standard, enabling precise flow regulation directly at the measuring point. This eliminates the need for separate flow control valves, simplifying system design and reducing installation costs. The valve is typically mounted in the foot of the meter, though head mounting is also available.
The DK32’s all-metal construction ensures high resistance to pressure, temperature, and aggressive media. Standard process connections are ¼” NPT internal thread, with other connection types available including other threads, compression fittings, and flange adapters. The meter requires no straight inlet or outlet runs, making it easy to install in space-constrained systems.
The DK32 is suitable for use in Safety Instrumented Systems with SIL 2 capability according to IEC 61508. In redundant design (1oo2), it can also be used in SIL 3 applications as a type A device. The meter holds approvals for hazardous areas including ATEX, IECEx, FM, and NEPSI, with protection types including Ex h, Ex i, Ex d, and Ex nA.
Typical applications for the DK32 include process or carrier gases, dosing of chemicals or additives, vessel inertization, purging, and monitoring of analyzer sample flow or seal gas/barrier fluids. The meter’s ability to handle both liquids and gases with the same device type, combined with its integrated needle valve and local indication, makes it a versatile and cost-effective solution for low-flow measurement in analyzer systems and purge panels.