KRACHT VC Gear Type Flow Meter

Overview

The KRACHT VC is a gear type flow meter for precise volumetric measurement of liquids in hydraulic, lubrication, fuel and process systems. KRACHT GmbH of Werdohl, Germany, now part of the Atlas Copco Group, builds the VC series in ten nominal sizes from 0.025 to 16, covering flow rates from 0.008 l/min up to 700 l/min, with working pressures of up to 480 bar and media temperatures from -60 to 210 °C depending on the specification. A typical measuring accuracy of up to ±0.3 % of the measured value and a repeatability of ±0.05 % in stable conditions make the KRACHT VC a reference instrument on test benches as well as a robust sensor for dosing and consumption measurement in the field.

Seven Star LLC supplies the KRACHT VC gear flow meter range to plant operators, OEM machine builders and test laboratories across the Sultanate of Oman and the GCC, with engineering support in Muscat. We help buyers decode the KRACHT type key, choose the right bearing, housing material, seal and electronics for the fluid in question, and confirm the measuring range before an order is released, so that the meter arrives ready for installation in Muscat, Sohar, Duqm or Salalah.

Measuring Principle of the KRACHT VC

The measuring unit of the KRACHT VC consists of two high-precision gears that are driven by the liquid flow according to the displacement principle. The gears run almost without contact in the measuring chamber, supported by ball or plain bearings, and every moving part is lubricated by the measured medium itself. Each tooth pitch moves a defined quantity of liquid from inlet to outlet, the so-called geometric tooth volume, which ranges from 0.025 cm³ on the smallest size to 16 cm³ on the largest. Because the KRACHT VC measures volumetrically, no straight calming sections are needed upstream or downstream, which allows machines and skids to be designed more compactly.

Lid-mounted sensors scan the gear movement without contact. During the rotation of the measuring unit by one tooth pitch, each sensor produces one signal corresponding to the tooth volume. With two sensors, the dual-channel scanning raises the resolution and also detects the flow direction, and four-fold evaluation of both channels quadruples the resolution again. As general engineering background, this positive displacement principle keeps accuracy largely independent of viscosity and flow profile, which is why gear meters are preferred for oils, resins and other viscous fluids where turbine or electromagnetic meters struggle.

Engineering Design and Electronics

KRACHT offers the KRACHT VC with plate mounting on all sizes and pipe connection on sizes 0.025 to 5. Housings are made from spheroidal cast iron GJS-400 or GJS-600, stainless steel 1.4404 or aluminium, with steel 1.7131 or stainless steel 1.4462 gears. Specification codes K1, K2, G1, G2, C1, H2, K3 and K4 combine ball bearings, hybrid ball bearings, high-clearance ball bearings or carbide plain bearings with these materials, so the KRACHT VC can be matched to lubricating fluids, poorly lubricating media such as solvents or AdBlue, or abrasive and filled compounds. Seals are available in FKM, EPDM, FEP, FFKM and FVMQ, and the maximum permissible pressure loss across the meter is 16 bar.

The standard electronics use an integrated pre-amplifier that converts the magnetic sensor pulses into square-wave signals with PNP, NPN or push-pull output, supplied with 10 to 30 V and rated IP 65. Alternatives include high-temperature and high-temperature PLUS versions with remote electronics, a low-temperature version, encoder versions with up to 2 500 pulses per revolution, IO-Link versions that calculate measured values internally, analogue versions with a 4 to 20 mA output, and ATEX/IECEx explosion-proof versions for hazardous areas.

Key Features of the KRACHT VC

The following characteristics explain why the KRACHT VC is widely specified for demanding measurement duties:

• Measuring ranges from 0.008 l/min on nominal size 0.025 up to 700 l/min on nominal size 16 give a suitable size for micro-dosing as well as large hydraulic flows.
• Typical measuring accuracy of up to ±0.3 % of the measured value with ±0.05 % repeatability, with accuracy characteristics traceable to the German accreditation body DAkkS.
• Maximum working pressure of up to 480 bar for most sizes, and K3 specification for 480 bar duty on the large nominal sizes 3, 5, 12 and 16.
• Media temperature capability from -60 °C to 210 °C depending on specification, seal material and electronics.
• Viscosity range up to 2 500 000 mm²/s, any mounting position and any flow direction.
• Low pressure drop, low noise emission and high-response measurement for dynamic test bench signals.
• Electronics options including encoder, IO-Link, 4 to 20 mA analogue and ATEX/IECEx versions.
• Spheroidal cast iron, stainless steel or aluminium housings with matched gear and bearing materials for each application.

Industrial Applications

KRACHT lists fuel consumption measurement, characteristic curve generation of hydraulic components, gear oil filling, indirect volumetric cylinder stroke measurement, ratio measurement in two- and multi-component dosing systems, and micro-flow measurement among the core uses of the KRACHT VC. In Oman and the wider GCC these duties appear in hydraulic test benches at oilfield service workshops, in lubrication and seal oil systems for compressors and turbines, in fuel consumption monitoring on gensets and marine engines, and in polyurethane, adhesive and resin dosing lines at manufacturing sites in the Sohar and Salalah free zones.

Seven Star LLC supports these projects by supplying the KRACHT VC together with the matching evaluation electronics, connection plates and cables, and by advising on the correct specification for the fluid, pressure and temperature on site. For workshops that also run KRACHT pumps, we can supply related products such as the KRACHT KF Series modular gear pump and the aluminium-bodied VCA gear meter from the same maker, keeping spares and documentation consistent across the installation.

Technical Specifications

The table below summarises the main KRACHT VC data from the manufacturer datasheet; final values depend on the selected size, bearing, material and electronics code:

How to Order

To order the KRACHT VC or replace an installed KRACHT VC, send Seven Star LLC your fluid, viscosity, flow range, pressure, temperature and required output signal, or simply the full KRACHT type key from an existing meter. Our instrumentation team in Muscat will confirm the specification, prepare a formal quotation and arrange delivery to your site anywhere in Oman or the GCC. The manufacturer datasheet is available for download on this page, and we can also quote the compact VCM gear flow meter from KRACHT where a compact alternative is preferred.