Description
KRAL OMH
Specially designed for high pressures up to 420 bar.
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This flow meter is suitable for measuring low-viscosity liquids. The OMH series is specifically designed to handle extremely high pressures up to 420 bar, which can occur in mechanical engineering, on test benches, and in hydraulic applications.
Specifications
| Technical Data | ||||||
|---|---|---|---|---|---|---|
| Property | OMH-013 | OMH-020 | OMH-032 | OMH-052 | OMH-068 | OMH-100 |
| Nominal diameter | ½ inch | ¾ inch | 1 inch | 1½ inch | 2 inch | 4 inch |
| Total length with threaded flange G | 150 mm | 185 mm | 255 mm | 320 mm | 385 mm | 500 mm |
| Weight with threaded flange G | 7 kg | 12 kg | 29 kg | 55 kg | 81 kg | 150 kg |
| Flow rate (l/h) | Qmax: 900, Qnom: 600, Qmin: 6 | Qmax: 2,700, Qnom: 1,800, Qmin: 18 | Qmax: 9,000, Qnom: 6,000, Qmin: 60 | Qmax: 31,500, Qnom: 21,000, Qmin: 210 | Qmax: 63,000, Qnom: 42,000, Qmin: 420 | Qmax: 180,000, Qnom: 120,000, Qmin: 1,200 |
| Flow rate (l/min) | Qmax: 15, Qnom: 10, Qmin: 0.1 | Qmax: 45, Qnom: 30, Qmin: 0.3 | Qmax: 150, Qnom: 100, Qmin: 1.0 | Qmax: 525, Qnom: 350, Qmin: 3.5 | Qmax: 1,050, Qnom: 700, Qmin: 7.0 | Qmax: 3,000, Qnom: 2,000, Qmin: 20 |
| Maximum pressure | 420 bar | 420 bar | 420 bar | 420 bar | 420 bar | 250 bar |
| Temperature | -20 to +200 °C | -20 to +200 °C | -20 to +200 °C | -20 to +200 °C | -20 to +200 °C | -20 to +200 °C |
| Viscosity | 1 to 1x10⁶ mm²/s | 1 to 1x10⁶ mm²/s | 1 to 1x10⁶ mm²/s | 1 to 1x10⁶ mm²/s | 1 to 1x10⁶ mm²/s | 1 to 1x10⁶ mm²/s |
| Measurement accuracy | ±0.1 % | ±0.1 % | ±0.1 % | ±0.1 % | ±0.1 % | ±0.1 % |
| Repeatability | ±0.01 % | ±0.01 % | ±0.01 % | ±0.01 % | ±0.01 % | ±0.01 % |
| K-factor | K2: 2,432 P/l, K3: 7,296 P/l, K4: 7,296 P/l | K2: 1,280 P/l, K3: 2,560 P/l, K4: 2,560 P/l | K2: 468 P/l, K3: 1,014 P/l, K4: 1,014 P/l | K2: 142 P/l, K3: 302 P/l, K4: 302 P/l | K2: 79.6 P/l, K3: 167 P/l, K4: 167 P/l | K2: 33.6 P/l, K3: 57.6 P/l, K4: 87.6 P/l |
| Frequency at Qnom | f2: 405 Hz, f3: 1,216 Hz, f4: 1,216 Hz | f2: 640 Hz, f3: 1,280 Hz, f4: 1,280 Hz | f2: 780 Hz, f3: 1,690 Hz, f4: 1,690 Hz | f2: 828 Hz, f3: 1,760 Hz, f4: 1,762 Hz | f2: 929 Hz, f3: 1,949 Hz, f4: 1,948 Hz | f2: 1,120 Hz, f3: 1,920 Hz, f4: 2,920 Hz |
| Sensors | ||||||
| Sensor models | BEG 06 / BEG 06A*, BEG 44, BEG 45 with BEV 13, BEG 53A / BEG 54A* | |||||
| Application | Ex-range (BEG 06 / BEG 06A*), High pressures and wide temperature range (BEG 44, BEG 45), Flow direction detection (BEG 53A / BEG 54A*) | |||||
| K-factor | K1 (BEG 06 / BEG 06A*), K2 (BEG 44), K3 (BEG 45), K4 (BEG 53A / BEG 54A*) | |||||
| Signal | Namur (BEG 06 / BEG 06A*), PNP (BEG 44, BEG 45), Push-pull (BEG 53A / BEG 54A*) | |||||
| Temperature | -25 to +85 °C (BEG 06 / BEG 06A*), -40 to +150 °C (BEG 44), -40 to +250 °C (BEG 45), -40 to +125 °C (BEG 53A / BEG 54A*) | |||||
| Maximum pressure | 350 bar (BEG 06 / BEG 06A*), 420 bar (BEG 44, BEG 45), 650 bar (BEG 53A / BEG 54A*) | |||||
| Technical Data (General) | ||||||
| Media | Chemically neutral, lubricating, clean, non-abrasive | |||||
| Flow direction detection | Optional with extended sensor package | |||||
| Temperature measurement | Optional with additional sensor | |||||
| Signal | PNP, Namur, Push-pull | |||||
| Signal detection | Via the pole wheel | |||||
| Process connections | DIN, threaded | |||||
| Materials | ||||||
| Housing | Spheroidal graphite iron | |||||
| Screws | Nitrided steel | |||||
| Bearings | Steel bearings | |||||
| Seals | FKM, other sealing materials on request | |||||
Product Overview
Large flow ranges usually require large pipe diameters, which in turn demands bulky flow meters. However, due to its compact measuring element, the OMH series fits into a small housing, offering a significant advantage — even at high flow rates. Pressure resistance is provided by a very rigid housing, compact dimensions, and proven precision; even under extreme pressure.
Key Features:
- Operates under high pressure up to 420 bar
- High precision
- Highly rigid spheroidal graphite iron housing
- Compact size, lightweight
- Low friction and minimal pressure loss
- No flow conditioning required
- Universally applicable
Extremely High Pressure Capacity
The most distinguishing feature. The OMH is specifically designed to handle pressures up to 420 bar (or even 6000 psi), and higher pressures (up to 630 bar) are possible with customer-specific versions (such as the OMX series). This is achieved through a very rigid housing made of spheroidal graphite iron.
Maintaining Accuracy Under High Pressure
Despite the extreme pressure, the OMH maintains the exceptional accuracy of KRAL flow meters ( linearity and repeatability). The rigid housing ensures that the geometry of the measuring element does not deform under pressure, which is essential for precision.
Wide Viscosity Range
Like other KRAL screw meters, the OMH can measure liquids from 1 to 1 million mm²/s (1 to 1,000,000 cSt).
Compact Size and Low Weight
For a meter in this pressure class, the OMH is relatively compact and lightweight, facilitating installation, especially in tight spaces on test benches or machines.
Robust Construction
This meter is constructed from high-quality materials such as spheroidal graphite iron for the housing and nitrided steel for the screws. This ensures a long service life and minimal wear, even during continuous high-pressure operations.
Bidirectional Measurement
The OMH can measure in both directions; this is useful, for example, in complex hydraulic circuits or test setups.
No Flow Conditioning
The KRAL OMH does not require straight inlet or outlet sections; this makes the installation significantly more flexible.
Application(s)
Mechanical Engineering
In systems and machines where hydraulic fluids or lubricants circulate under very high pressure. The OMH can measure the flow of hydraulic oils for control and positioning of actuators, which is essential for the optimal performance of machines and systems. The robust design and accuracy are crucial for the reliable operation of heavy machinery.
Test Benches
This is a very important application area. OMH meters are widely used on test benches for engines, gearboxes, pumps, and other hydraulic components. Here, extreme accuracy under high pressure is required to evaluate performance, calibrate, and ensure the quality of products. They provide reliable measurement data for extensive testing under realistic conditions.
Hydraulic Applications
Wherever hydraulic systems operate under high pressure. This includes various industrial processes where accurate control of oil flow is necessary. The robust construction guarantees high measurement accuracy, even at the highest system pressures.
Oil and Gas Industry (Specific High-Pressure Applications)
While the OMG and OMP series are more widely used, the OMH can also be utilized for specific tasks in the oil and gas sector where extreme pressures occur, such as measuring consumption in certain gas turbines or high-pressure systems.
