Application-oriented and always ready for new tasks

Simply twist off the cover, insert the module until it clicks, twist the cover back on and that‘s it. There is no need for tools or to interrupt the process for the functionality to be scaled at will. It is just as easy to replace the measuring scale in
Modularity of electronics

Using the purely mechanical version as a base, you can add or replace electronic modules, scaling functions to your needs. Anything is possible, from analogue flow measurement without auxiliary power to digital integration into a fieldbus system.

Just twist off the cover, insert the module until it clicks, twist the cover back on and you‘re finished – no tools, no process interruption. And it‘s just as easy to replace the measuring scale when there‘s a change in the application. It couldn‘t be easier.

Electrical options:

Limit switches

Limit switch options of the H250 M40 flowmeter

3 versions:

  • 2-wire NAMUR contact as per IEC 60947-5-6
  • 3-wire transistor output 10-30 VDC
  • Potential-free reed switch

2-wire sensor module with 4…20 mA current output

2-wire sensor module option the H250 M40 flowmeter
  • 4…20 mA for 0…100 % flow
  • Can be combined with limit switches
  • 14-30 VDC power supply
  • HART® certified communication
  • Internal interface to extension modules
  • Simple loop-check at push of button

Totaliser with pulse output, limit switches and LCD

Totaliser option with pulse output, limit switches and LCD
  • Counter module with graphic display to indicate flow, counter reading, additional information and operating menu
  • Power supply via sensor module
  • Operation and parameter setting via internal microswitch or externally using a bar magnet

Fieldbus communication

Fieldbus communication options for the H250 M40
  • PROFIBUS® PA or FOUNDATION™ fieldbus
  • Power supply for entire device from 2-wire bus (16 mA current consumption)
  • Direct bus communication without additional converter
Logos of supported communication protocols of the H250 M40 flowmeter: HART®, PROFIBUS® PA, FOUNDATION™ fieldbus

A device that meets all requirements

The explosion proof housing guarantees safe application in hazardous areas with non-sparking, explosion proof and dust ignition proof explosion protection – globally approved for the use in a wide range of usage zones.
Explosion proof housing
All electronic components are designed intrinsically safe and non-sparking and can be used in areas that are explosive due to the presence of gas or dust.
Intrinsically safe electronics

Globally approved for hazardous areas

H250 M40 from KROHNE offers a universal Ex-design across a wide range of usage zones and protection types.

All electronic components are designed intrinsically safe and non-sparking and can be used in areas that are explosive due to the presence of gas or dust. As an option, the same components, featuring a safety housing, can be installed as explosion proof devices. One device can thus accommodate the different regional explosion protection strategies.

H250 M40 is ATEX-, IECEx- and FM-approved for the USA and Canada and also according to NEPSI for China. In addition, the measuring device also features other local approvals such as INMETRO, CCOE/PESO, KGS and EAC/GOST-R.

Whether it‘s intrinsically safe or explosion proof – the devices are designed as IP66/IP68 or NEMA 4X/6 as standard. An IP69K version is also available on request.

Ex approvals of the flowmeter H250 M40

Special indicator variants for extreme operating conditions

Close-up image of the H250 M40 variable area flowmeter with stainless steel housing

With the indicator housing made of stainless steel, the H250 M40 R withstands attacks from salt fogs and contaminated precipitates. It can be reliably used in corrosive atmospheres and is perfectly suited for use in spray water zones, such as in the food and beverage industries as it features ingress protection type IP69K.

Unique to date: The indestructible stainless steel housing is also available on request in an explosion proof version for use in hazardous areas.

As a high-temperature variant, the H250 M40 HT measuring device is suitable both for very high product temperatures up to +400 °C / +752 °F as well as cryogenic applications down to -200 °C / -328 °F. The increased distance between the measuring tube and the display makes it easier to insulate the measuring tube.

The rugged stainless steel housing M40 R complements the robust measuring cones to withstand the roughest conditions – both from the process and from the environment.
H250 M40 R

Robust design for harsh process conditions

The measuring principle allows for a robust, closed tube design without sensor feedthrough, as the height of the float is transferred to the indicator by way of a magnetic coupling. This enables high pressure versions that can withstand up to 900 barg / 13,000 psig.

All wetted, pressurised parts are made as standard of 1.4404/316L stainless steel and meet the requirements of the NACE MR0175 standard. To guarantee the longevity of the device even with chemically harsh products, it is possible to use special materials such as Hastelloy®, titanium, Monel®, etc. in production. In addition, the H250 C M40 is also available with a PTFE liner for applications involving aggressive acids and bases.

The EHEDG certified H250 F M40 for use in hygienic applications in the food industry.
Hygienic EHEDG certified design

EHEDG certification for use in the food and pharma industries

The H250 F M40 is the only variable area flowmeter with EHEDG approval for food and pharmaceutical applications. FDA-compliant materials meet strict hygienic and legal regulations. A design with no dead spaces or stagnation zones as well as the electro-polished surface of the wetted parts with a surface roughness Ra <0.8 μm make it difficult for deposits to settle and facilitate proper cleaning.

As an option, it is possible to refine the measuring range span to 100:1. This way the otherwise necessary additional measuring devices for small quantities are no longer necessary.
Expanded measuring range

Expanded measuring range for more process information

Depending on the technology, the standard measuring range span of the H250 M40 is 10:1. As an option, it is possible to refine the measuring range span – and this is worldwide unique for measuring devices in this category – to 100:1. This way the otherwise necessary additional measuring devices for small quantities are no longer necessary.

The right solution for any installation requirement

Typically, variable area flowmeters are installed vertically in rising pipes and the product must flow through them from bottom to top. This can lead to considerable expense.

Free choice of installation direction

The versions H250 H M40 and H250 U M40 offer the possibility to install the flowmeter in horizontal or even in descending pipes.

H250 H M40 variable area flowmeter for use in horizontal pipes

H250 H M40

For use in horizontal pipes

H250 U M40 variable area flowmeter for use in descending pipes

H250 U M40

For use in descending pipes

Free choice of process connections

Thanks to a wide variety of process connections – common flange connections in accordance with DIN, ASME and JIS, male and female threads as well as clamp connections – this device is available to all sectors of industry.

Thanks to a wide variety of process connections – common flange connections in accordance with DIN, ASME and JIS, male and female threads as well as clamp connections – this device is available to all sectors of industry.
Comparison of available process connections

The cost-effective and reliable all-rounder

User-friendliness was the top priority for KROHNE when developing the H250 M40. Following simple mechanical installation and start-up with an electrical connection if applicable, the device is immediately ready to use and it is good for long-term maintenance-free operation.

High flexibility as well as low purchase and operating costs make the H250 M40 variable area flowmeter a cost-effective all-rounder!

Today, as the world’s market leader, we cover a variety of applications with our comprehensive product portfolio of metal and glass cones.

Variable area metal cone devices at a glance

  • For extreme process conditions
  • High/low temperatures
  • High pressures
  • Aggressive products
  • Limit switches, current output, counters and communication possible
Variable area flowmeter H250 M40 the new standard device, explosion proof and intrinsically safe

H250 M40

The new standard device, explosion proof and intrinsically safe

Variable area flowmeter DK32, 34, 37 with mechanical or electronic indicator and metering valve to set flow value accurately

DK32, 34, 37

With mechanical or electronic indicator and metering valve to set flow value accurately

Variable area glass cone devices at a glance

  • Very reasonably priced
  • Product visible
  • Up to max. 10 barg / 145 psig and +100 °C / +212 °F
  • Change of glass possible
  • Optional: limit switches, current output
Variable area flowmeter DK46, 47, 48, 800 small and compact dosing meters with valve

DK46, 47, 48, 800

Small and compact dosing meters with valve

Variable area flowmeter VA40, 45 all-purpose flowmeter with various process connections

VA40, 45

All-purpose flowmeters with various process connections

From universal to one-of-a-kind

Calibration of the flowmeter H250 M40

At KROHNE, the modular device design of the H250 M40 combined with a flexible production structure form the basis for application and customer specific versions.

As with every KROHNE variable area flowmeter, you can count on reliability and repeatability. Each device is individually calibrated for the respective application. And the robust metal version – available in a variety of materials – provides a high degree of resistance to pressure, temperature and medium.

Learn more about proven quality from KROHNE

Automated welding processes with radiographic inspection and surface crack detection as well as other quality assessments such as material certificates, pressure, leak and hardness testing, all under the control of a seamless quality management system, form the basis for the devices being authorised for use in areas where safety is critical such as chemical plants and nuclear power stations.