Variable Area Flow Meter

Market overview variable area flowmeter

There are many producers and distributors of variable area flowmeters on the market.
On this page we have tried to give an independent, but certainly not complete, overview of the devices available on the market.
Please note that the overview information may not reflect the latest technical data. You can find them by clicking on the link to the data sheet of the supplier.

As far as the agreement of the supplier for the publication of a picture is present, also a picture is indicated.
For a better overview, the products have been grouped into variable area flowmeters with metal measuring tube, variable area flowmeters with glass measuring tube and variable area flowmeters with plastic measuring tube.

If you are looking for the manufacturer of a model code, the following link to our model overview will certainly be helpful.
Type overview (alphabetical order)

Variable area flowmeters with metal measuring tube

For higher operating pressures or opaque fluids, conical metal tubes or cylindrical measuring tubes with orifice plate and conical float are used.
The position of the float is transmitted by magnetic force to a display unit mounted on the instrument without contact.
In some types, a spring is installed as a restoring force for the float. This means that the devices can also be used for horizontal flow or flow from top to bottom.
Electrical transmitters built into the display unit, also with Hart®, Profibus or other protocols, make remote transmission of measured values possible.

RAKD -Yokogawa

Measuring range: 0,1-1 to 25-250 L/h water
4-40 to 800-8000 L/h air
Connection:thread 1/4-3/8 G/NPT, flange DN15-DN40, Cutting ring
Material: st.st.
Max. pressure/temp.: -25 °C to 250 °C
Accuracy: ± 4% VDI/VDE 3513-2 (q50%)
Output: contacts, analog output
Approvals:ATEX, IECEx, NEPSI etc.

Link to the manufacturer datasheet

RAMC - Yokogawa

Measuring range:2,5-25 to 13-130 m³/h water
0,07-0,7 to 130-1300 Nm³/h air
Connection: flange DN15-DN150 (EN1092-1), ASME, thread
Material: st. st.
Max. pressure/temp.: PN40 (option: 700bar)/-196to +400 °C
Accuracy: ± 1,6% VDI/VDE 3513-2 (q50%)
Output: contacts, analog output,
Approvals:ATEX, IECEx, NEPSI etc.

Link to the manufacturer datasheet

BGF-Heinrichs

Measuring range:10-100 l/h to 6-60 m³/h water
0,3-3 to 170-1700 m³/h air
Connection:flange DN15-80 (EN 1092-1), ASME B16.5, JIS, NPT, pipe fitting, TriClamp
Material: st.st.
Max. pressure/temp.: 40 (400) bar/-40 to 350 °C
Accuracy: ± 2% q50% VDI/VDE 3513-2
Output:: contacts, analog output, Hart®, FIELDBUS®,, Profibus-PA®
Approvals: ATEX

Link to the manufacturer datasheet

BGN-Heinrichs

Measuring range:0,5-5 l/h to 13-130 m³/h water
15-150 l/h to 240-2400 m³/h air
Connection: flange DN15-150 (EN 1092-1), ASME B16.5, JIS, NPT, pipe fitting, TriClam
Material: st.st., Titan, Hastelloy, Monel
Max. pressure/temp.: 40 (600) bar/-40 to 350 °C
Accuracy: ± 1,6% q50% VDI/VDE 3513-2
Output: contacts, analog output, Hart®, FIELDBUS®,, Profibus-PA®
Approvals: ATEX

Link to the manufacturer datasheet

DK32/34 - Krohne

Measuring range: 0,15-1,5 to 15-150 L/h water
0,16-1,6 to 480-4800 l/h air
Connection:1/4 NPT; G1/4, Ermeto, Swagelok®, flange
Material: st.st.
Max. pressure/temp.:130 (202) bar/200 °C
Accuracy: ± 3% FS.
Output contacts, analog output, bargraph display, Hart®
Approvals:ATEX / IECEx / UKEx

Link to the manufacturer datasheet

DK37 M8 - Krohne

Measuring range: 0,15-1,5 to 25-250 L/h water
0,16-1,6 to 800.-8000 l/h air
Connection:1/4 NPT; G1/4, Ermeto, Swagelok®, flange
Material: st.st.
Max. pressure/temp.:130 (202) bar/200 °C
Accuracy: ± 2% FS.
Output: contacts, analog output, bargraph display, Hart®
Approvals:ATEX / IECEx / UKEx

Link to the manufacturer datasheet

H250 M40 - Krohne

Measuring range: 0,15-1,5 L/h to 10 -100 m³/h water
0,16-1,6 NL/h to 280-2800 Nm³/h air
Connection: flange DN 15- DN150 (EN 1092-1), ASME (B16.5), JIS, thread:1/2...2 G/NPT, sanitary connect.
Material: st.st., Titanium, Hastelloy®
Max.pressure/temp.: 1000 bar/-196..+400 °C
Accuracy: ± 1,5% FS.
Output: analog output, contact, pulse, Hart® , FIELDBUS®, Profibus-PA®
Approvals: SIL2, ATEX, IECEx, etc.

Link to the manufacturer datasheet

H250 M8 - Krohne

Measuring range: 0,18-1,8 to 630 -6.300 L/h water
0,42-4,2 NL/h to 18-180 Nm³/h air
Connection: flange DN15..DN50 (EN 1092-1), ASME, JIS (B2220), thread: 1/2 ..1 G/NPT, sanitary connect.
Material: st.st., Titanium, Hastelloy
Max. pressure/temp.: 145 bar/-196 to +200 °C
Accuracy: ± 1,6% VDI/VDE 3513-2 (q50% )
Output: analog output, contact, Hart
Approvals: SIL2, ATEX, IECEx, etc.

Link to the manufacturer datasheet

KDS/BGK-Heinrichs

Measuring range: 0,1-1 to 20-200 L/h water
3-30 to 600-6000 NL/h air
Connection:1/4 NPT, Ermeto, Swagelok®, flange
Material: st.st.
Max. pressure/temp.: PN63 (Option: 40 bar)/-40 to +130 °C
Accuracy: ± 3 % VDI/VDE 3513-2 (q50%)
Output:: contacts, analog output
Approvals: ATEX, SIL

Link to the manufacturer datasheet

RE250 - Mecon

Measuring range:0,5-5 l/h to 10-100 m³/h water
15-150 L/h to 300-3000 m³/h air
Connection: flangee DN15 - DN150 (EN 1092-1), ASME, thread 1/4"..2" G/NPT
Material: st.st.,Hastelloy
Max. pressure/temp.: 160 (600) bar/-40 to 350 °C
Accuracy: ± 1,6% VDI/VDE 3513-2 (q50%)
Output: contacts, analog output, Hart®, Profibus-PA®
Approvals: ATEX

Link to the manufacturer datasheet

SWK - Kobold

Measuring range: 0,05-0,1 to 13-24 L/min water
Connection:G 1/2"
Material: brass, st.st., PVC
Max. pressure/temp.: 250 bar / +100 °C
Accuracy: ± 4 % FS
Output: 1 contact

Link to the manufacturer datasheet

SMV - Kobold

Measuring range: 0,1 - 1 l/min to 10 - 250 L/min water
Connection:1/4" to 1 1/4" G and NPT
Material: brass, st.st.
Max. pressure/temp.:350 bar / +100 °C
Accuracy: ± 5 % FS
Output: 1 contact
Approvals: ATEX, cCSAus, DMT

Link to the manufacturer datasheet

SMW - Kobold

Measuring range: 0.2 - 3 to 10 - 120 L/min water
Connection:1/4" to 1 G and NPT
Material: brass, st.st.
Max. pressure/temp.:350 bar /+100 °C
Accuracy: ± 5 % FS
Output: 1 contact
Approvals: cCSAus

Link to the manufacturer datasheet

VKM - Kobold

Measuring range: 0,01-0,07 to 8-80 L/min liquid
Viskositäty compensated: 1 - 540 mm²/s
Connection:1/4" to 1" (11/4") G and NPT
Material: brass, st.st.
Max. pressure/temp.:350 bar /+100 °C
Accuracy: ± 4 % FS
Output: 2 contacts, 4-20 mA
Approvals: cCSAus, ATEX, IECEx

Link to the manufacturer datasheet

MP- Kytola

Measuring range:1 – 10 to 40 – 400 L/h water
60 - 320 to 1000 - 12000 NL/h air
Connection: thread G1/2, 1/2" NPT
Material: st. steel
Max. pressure/temp.: 235 bar/ +150 °C
Accuracy: ± 5% FS
Output: contacts
Approvals: ATEX

Link zum Hersteller Datenblatt

ML- Kytola

Measuring range: 100 – 1000 bis 6000 – 60000 L/h.Wasser
Connection: flange DN 25 -100, ANSI 1"-4"I
Material: st. steel
Max. pressure/temp.: PN40 / +110 °C
Accuracy: ± 5% FS
Output: contacts
Approvals: ATEX

Link zum Hersteller Datenblatt

Variable area flowmeters with glass measuring tube

Variable area flowmeter with glass measuring tube is the traditional design of variable area flowmeter.
Here, the measuring tube is made of glass, which is often mounted in a protective fitting to protect against glass breakage. The process fittings are made of a wide variety of materials. The position of the float, and thus the flow rate, is read directly on a scale mounted on the measuring tube or on the fitting.
The advantage of the transparent measuring tube is that the user can directly see the flow of the fluid. Thus, the fluid can be visually inspected and changes in the fluid, impurities or air bubbles can be quickly detected.
Variable area flowmeters with glass measuring tube are mainly used in laboratories, in the chemical industry, in the food industry and in the water and wastewater industry.
Variable area flowmeters are the ideal devices to measure the flow and at the same time provide a visual check of the flow

K09 -Heinrichs

Measuring range:0,02-0,26 to 10-100 L/h water
2-20 to 300-3000 NL/h air
Connection: thread 1/4" G/NPT
Material Connection: st.st.
Max. pressure/temp.: PN16/ -20 to +100 °C
Accuracy: ±3% q50% VDI/VDE 3513-2
Output/Accessories: 1 contact, valve, flow regulator
Approvals: ATEX

Link to the manufacturer datasheet

K12 -Heinrichs

Measuring range:0,25-2,5 to 16-160 L/h water
0,5-5 to 500-5000 NL/h air
Connection: thread 1/4" G/NPT
Material Connection: st.st.
Max. pressure/temp.: PN16/ -20 to +100 °C
Accuracy: ± 2,5% q50% VDI/VDE 3513-2
Output/Accessories: 1 contact, valve, flow regulatorr
Approvals: ATEX

Link to the manufacturer datasheet

K17 -Heinrichs

Measuring range:0,1-1 to 10-100 L/h water
5-50 to 300-3000 NL/h air
Connection: thread 1/4" G/NPT
Material Connection: st.st.
Max. pressure/temp.: PN10/ -20 to +100 °C
Accuracy: ± 2,0% q50% VDI/VDE 3513-2
Output/Accessories: 1 contact, valve, flow regulator
Approvals: ATEX

Link to the manufacturer datasheet

V31-Heinrichs

Measuring range3-30 L/h to 1-10 m³/h water
36-360 NL/h to 18-180 Nm³/h air
Connection:thread 1/2"-2" G/NPT, flange DN15- DN50
Material Connection: st.st., PVC, PVDF
Max. pressure/temp.: 15 bar / -20 to +80 °C
Accuracy: ±1,6 (2,5)% q50% VDI/VDE 3513-2
Output: 2 contacts
Approvals:ATEX

Link to the manufacturer datasheet

RAGK - Yokogawa

Measuring range:0,0025-0,025 to 63-630 L/h water
0,19-1,9 to 630-6300 L/h air
Connection: 1/4" - 3/8"
Material Connection: st.st., PP
Max. pressure/temp.:16bar/-25 to +80 °C
Accuracy: ±2,5 - 6% acc. VDI/VDE 3513-2
Output/Accessories: contact, valve, flow regulator
Approvals:ATEX, IECEx

Link to the manufacturer datasheet

RAGL - Yokogawa

Measuring range:0,0002-0,02 to 10-100 L/h water
0,02-0,2 to 350-3500 L/h air
nschluss: 1/4" G, NPT
Material Connection: st.st., PP
Max. pressure/temp.:16bar/-20 to +130 °C
Accuracy: ± 1,6 - 4% acc. VDI/VDE 3513-2
Output/Accessories: 1 contact, valve, flow regulator
Approvals:ATEX, IECEx

Link to the manufacturer datasheet

RAGN - Yokogawa

Measuring range: 0,0025-0,025 L/h to 1-100 m³/h water
0,19-1,9 L/h to 160-1600 m/³h air
Connection:thread 1/2-2 1/2" G/NPT, flange
Material: st.st.
Max. pressure/temp.: 16 bar/ -25 to +100 °C
Accuracy: ± 1,6% acc. VDI/VDE 3513-2 (q50%)
Output: contacts
Approvals:ATEX, IECEx, NEPSI

Link to the manufacturer datasheet

Tubux M30 - Mecon

Measuring range:0,01-0,1 L/h to 2,5-25 m³/h water
0,1-1 L/h to 48-480 Nm³/h air
Connection: thread 1/4" - 2" G, NPT, flange DN10-DN80
Material Connection:st.st., PVC, PVDF
Max. pressure/temp.:10 bar/ -10 to +150 °C
Accuracy: ± 1,6 % acc. VDI/VDE 3513-2
Output: contacts
Approvals: ATEX

Link to the manufacturer datasheet

DK46/47/48/800 - Krohne

Measuring range:0,25-2,5 to 16-160 L/h water
0,5-5 to 500-5000 NL/h air
Connection:1/4" G/NPT, Ermeto, Swagelok a.o.
Material connection: brass, st. steel, PVDF
Max. pressure/temp.:10 bar/-5 to +100 °C
Accuracy: ± 1 to 4% q50% VDI/VDE 3513, Blatt 2
Output/Accessories: Valves, contacts, panel mounting, flow regulator
Approvals:ATEX, SIL

Link zum Hersteller Datenblatt

VA40 / 45- Krohne

Measuring range:0,04-0,4 L/h to 1-10 m³/h water
7-70 L/h to 31-310 Nm³/h air
Connection: thread 1/2"-2" G/NPT, Flansch DN15-80, Schlauchtülle
Material connection: st. steel, PVDF
Max. pressure/temp.: 10bar/ -20 to +100 °C
Accuracy: ± 1 -2,5 % q50% VDI/VDE 3513, Blatt 2
Output: Contacts, analogue output
Approvals: ATEX

Link zum Hersteller Datenblatt

Q-flow - Vögtlin

Measuring range:0,06-1,2 to 8-50 NL/h air
Connection:thread G 1/4"
Material connection:brass nickel plated
Max. pressure/temp.:10 bar/0 to +100 °C
Accuracy: ± 5% F.S.
Accessorie: Valves

Link zum Hersteller Datenblatt

Variable area flowmeters with plastic measuring tube

Variable area flowmeters with plastic measuring tubes are often an economical alternative to variable area flowmeters with glass measuring tubes.
The measuring tube is made of transparent Trogamit®, polysulfone, PVC or acrylic glass. It is manufactured by injection molding or mechanical processing. A connection thread is normally integrated directly during the manufacturing process. By means of commercially available connecting parts, the devices can be easily adapted to the plant conditions.
The position of the float, and therefore the flow rate, is read directly from a scale mounted on the measuring tube. As with the variable area flowmeter with glass measuring tube, the user can directly see the flow of the fluid and thus visually monitor the fluid and the flow.
The advantage of the plastic measuring tube is its significantly higher break resistance and its inexpensive production. Disadvantage, the often lower measuring accuracy, especially with larger temperature fluctuations of the measured fluid.
Variable area flowmeters are used wherever low-cost, chemically and corrosion resistant devices are required. Examples are water technology, heating and cooling systems, chemical industry and food industry.

KSV - Kobold

Measuring range: 0,25 - 1,5 to 10 - 80 L/h water
20 - 80 NL/h to 0,5 - 2,4 Nm³/h air
Connection:thread 1/8" NPT
Material:Polysulfon/brass, Polysulfone/st.st.
Max. pressure/temp.:6 bar/ +120 °C
Accuracy: ± 6% FS
Accessorie: Valve

Link to the manufacturer datasheet

KSK - Kobold

Measuring range: 1,5 - 11 to 100 - 1000 L/h water
0,15 - 0,45 to 20 - 105 Nm³/h air
Connection:thread 1/4"to 2" G, DN15-DN25 Glue pipe
Material:Trogamid, Polysulfone, PVDF
Max. pressure/temp.:10 bar/ +140 °C
Accuracy: class 4 acc. VDI
Output: contact

Link to the manufacturer datasheet

KSM - Kobold

Measuring range:15 -150 to 8000 - 60 000 L/h water
0,8 - 5 to 300 - 2500 m³/h air
Connection:thread 1/2"to 3" G, Glue pipe
Material:Trogamid, Polysulfone
m Max. pressure/temp.:16 bar/ +100 °C
Accuracy: class 4 acc. VDI
Output: contact

Link to the manufacturer datasheet

Trogflux-KBF - Mecon

Measuring range:2-20 to 160-1600 L/h water
45-450 L/h to 2,5-25 Nm³/h air
Connection:thread 1/4"-1" G, Glue pipe
Material: Trogamid®
Max. pressure/temp.:10 bar/ -10 to +60 °C
Accuracy: ± 1,6% acc. VDI/VDE 3513-2
Output: contacts

Link to the manufacturer datasheet

Trogflux - Mecon

Measuring range:0,65-6 L/h to 2,5-25 m³/h water
0,14-1,4 to 143-430 m³/h air
Connection: thread 1/4"-2" G, Glue pipe
Material: Trogamid®, Polysulfone
Max. pressure/temp.:10 bar/ 90 °C
Accuracy: ± 1,6% acc. VDI/VDE 3513-2
Output: contacts

Link to the manufacturer datasheet

K20 - Krohne

Measuring range:5-60 L/h to 8-25 m³/h water
Connection:thread 1/2"-2" G, Gluing sleeve DN15-50
Material: Polysulfone
Max. pressure/temp.:12 bar/ -10 to +60 °C
Accuracy: ± 2,5 % q50% VDI/VDE 3513, Blatt 2
Output: ---

Link to the manufacturer datasheet

A, C, D - Kytola

Length: 130 ,165 and 210 mm
Measuring range:2 – 20 mL/min to 10-100 L/h water
0,1 – 0,9 NL/min to 500 – 2500 NL/min air
Connection:thread G 3/8" to G 1
Material:Akryl (PMMA)
Max. pressure/temp.: 20 bar/ +75 °C
Accuracy: ± 5% FS

Link to the manufacturer datasheet

H - Kytola

Length: 180, 255,382 mm
Measuring range: 0,02 – 0,11 to 4 – 22 m³/h water
0,015 – 0,07 to 2 – 14 Nm³//min air
Connection:thread G 1/2"-11/4", 1/2"-11/4" NPT
Material:Grilamid (PA-12)®
Material Connection: PVC
Max. pressure/temp.: 10 bar/ +50 °C
Accuracy: ± 5% FS

Link to the manufacturer datasheet

K - Kytola

Measuring range:7,5 – 40 to 10-120 L/min water
200 – 1200 NL/min to 400 – 2800 NL/min air
Connection:thread G 1", 1" NPT
Material:Grilamid (PA-12)®
Material Connection: Aluminium, st. steel, Nylon
Max. pressure/temp.: 30 bar/ +80 (120) °C
Accuracy: ± 5% FS
Output: Analogue output

Link to the manufacturer datasheet

T- Kytola

Measuring range:7,5 – 55 to 50 – 400 L/min water
0,3 – 1,9 to 1 – 12 Nm³//min air
Connection:thread G 2, 2" NPT, flange DN 50, 2"
Material:Grilamid (PA-12)®
Material Connection:Aluminium, st. steel
Max. pressure/temp.: 20 bar/ +80 (120) °C
Accuracy: ± 5% FS

Link to the manufacturer datasheet