Kobold DON Oval Gear Flow Meter

Fits viscous or clean liquid metering where you need positive-displacement accuracy across a wide size ladder (0.5…36 l/h up to 150…2500 l/min by model) and configurable pulse, analogue, LCD, or IO-Link electronics.

Key advantages

Wide oval-gear size ladder — 0.5…36 l/h to 150…2500 l/min (DON-x04…x60).
±0.2…1% of reading — Size/electronics dependent; repeatability typ. ±0.03%.
Viscosity to 1000 cP — Standard; higher with special-cut rotors.
Flexible electronics — Pulse, 4–20 mA, LCD/U-PACE, mechanical register, IO-Link.
Ex options by code — ATEX/IECEx mechanical and electronic builds (BA/BE/GE etc.).

Typical applications

Viscous or clean liquid metering on chemical, oil, and dosing skids.
Positive-displacement duty where magmeters struggle with low conductivity or high viscosity.
Installs needing pulse, analogue, or IO-Link electronics on aluminium or SST bodies.

Selection guide

Range / size — 0.5…36 l/h to 150…2500 l/min (model sizes DON-x04…x60). Pick size from working flow, not pump nameplate max alone.
Accuracy — ±0.2…1% of reading (size/electronics dependent); repeatability typ. ±0.03%.
Viscosity — Up to 1000 cP standard (higher with special cut rotors).
Pressure — pmax up to 100 bar (model/screw option dependent; flanges limited by flange rating).
Outputs — Pulse (Hall/reed/quad); 4–20 mA; LCD/U-PACE electronics; alarms; mechanical register; IO-Link (U-PACE).
Supply — Hall push-pull external supply; reed 2-wire; analogue loop 16…32 VDC; U-PACE 19–30 VDC.
Process connection — G ⅛…G 4 female thread; flange DN25…DN100 / ASME 1…4 in (order codes R/N/F/A/B…).
Wetted materials — Aluminium or stainless steel 1.4404 body; oval wheels PPS GF30/PTFE/PEEK or SST; axes 1.4404; O-rings FKM/NBR/FEP/Fluoroprene.
Media / ambient — Media −20…+80 °C typical electronics options; up to +150 °C with pulse + cooling fins / selected O-rings. Ambient −20…+80 °C (electronics); M4 register 0…+60 °C.
IP — IP66/67 (IP65 for mechanical register option M4).
Display — Optional LCD / U-PACE / mechanical register.
Area classification — Mechanical Ex h IIC T4/T3 Gb and electronic Ex options per order (BA/BE/GE etc.). Approvals listed: ATEX, IECEx, CE.

Common mistakes

Ordering a size from max pump flow instead of the actual working band — oval-gear meters lose resolution at the bottom of an oversized range.
Specifying aluminium body / wrong O-ring for media that need 1.4404 and FEP/Fluoroprene — wetted parts are order-code choices.
Assuming every electronics option reaches +150 °C media — typical electronics sit −20…+80 °C; high temp needs pulse + cooling fins / selected O-rings.
Claiming ATEX/IECEx without the matching mechanical/electronic Ex order codes (BA/BE/GE etc.) on the quote.
Expecting IP66/67 on the M4 mechanical register path — that option is IP65.

When to RFQ / what to tell us

Fluid, viscosity (cP), density, and working min/max flow + units.
Process pressure and media temperature (and whether >80 °C needs high-temp options).
Process connection (thread G size or flange DN/ASME) and preferred wetted materials / O-ring.
Output: pulse type, 4–20 mA, LCD/U-PACE, mechanical register, IO-Link.
Supply available, IP need, hazardous-area marks required, quantity, ship-to country.

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Specs

Spec	Value
SKU	42453
Brand	Kobold
Model	DON
Product type	positivedisplacementflow_meter
Measuring range	0.5…36 l/h to 150…2500 l/min (by model size DON-x04…x60)
Accuracy	±0.2…1% of reading (size/electronics dependent); repeatability typ. ±0.03%
Output signal	Pulse (Hall/reed/quad); 4–20 mA; LCD/U-PACE electronics; alarms; mechanical register; IO-Link (U-PACE)
Supply voltage	Hall push-pull external supply; reed 2-wire; analogue loop 16…32 VDC; U-PACE 19–30 VDC
Process connection	G ⅛…G 4 female thread; flange DN25…DN100 / ASME 1…4 in (per order codes R/N/F/A/B…)
Wetted materials	Aluminium or stainless steel 1.4404 body; oval wheels PPS GF30/PTFE/PEEK or SST; axes 1.4404; O-rings FKM/NBR/FEP/Fluoroprene
Housing material	Aluminium or SST body; mechanical register housing enamelled die-cast aluminium (M4)
IP rating	IP66/67 (IP65 for mechanical register option M4)
Media temperature	−20…+80 °C typical electronics options; up to +150 °C with pulse + cooling fins / selected O-rings (datasheet)
Ambient temperature	−20…+80 °C (electronics); M4 register 0…+60 °C
Process pressure	pmax up to 100 bar (model/screw option dependent; flanges limited by flange rating)
Viscosity	Up to 1000 cP standard (higher with special cut rotors)
Communication	IO-Link via U-PACE CT electronics
Display	Optional LCD / U-PACE / mechanical register
Approvals	ATEX; IECEx; CE
Hazardous area	Mechanical Ex h IIC T4/T3 Gb and electronic Ex options per order (BA/BE/GE etc.)
Notes	Specs from KOBOLD don-GB-flow datasheet (2/09-2026).

Documents

FAQ

Q: Is oval gear right for my fluid? A: DON is a positive-displacement oval-gear meter for liquids within the published viscosity and material limits (up to 1000 cP standard). For conductive water-like flows you may want a magmeter instead — send fluid and viscosity in the RFQ.

Q: Pulse, 4–20 mA, or IO-Link — which electronics? A: Options include pulse (Hall/reed/quad), 4–20 mA, LCD/U-PACE, mechanical register, and IO-Link via U-PACE. Supply limits differ (analogue loop 16…32 VDC; U-PACE 19–30 VDC). Lock host and available voltage first.

Q: Which Ex marks can I claim? A: Datasheet lists ATEX, IECEx, CE, with mechanical Ex h IIC T4/T3 Gb and electronic Ex options by order code (BA/BE/GE etc.). Only ordered codes and certificates apply.

Q: What should I send for a quote? A: Flow band, viscosity, pressure, temperature, connection, wetted materials, output, Ex needs, quantity. Compatible with systems using Kobold DON if you need a drop-in check — we do not claim authorized-dealer status.