High and Low Viscosity Liquids - Helical
Helical Screw Flowmeters
Meter Principle
A positive Displacement meter divides the flow into discrete 'pockets'. This prevents the flow by-passing its rotor and producing errors.
The Helical Screw Flowmeter has rotor scrolls which accept and release continuous flow. While the flow is being transported through the centre portion of the meter, it is trapped by the 'flights' of the scrolls, these form positive displacement 'pockets'. Smooth flow is assured and no pulsation is created by the meter itself. A sensor detects the motion of the rotor and produces a high resolution pulse output.
Features
OM Series flowrate range: 0.015 to 7500 l/min. Including special extended range.
Sizes: 13mm (1/2") to 150mm (6") with BSP screwed entries or DIN flanges. Special connections can be supplied to purchasers' requirements.
Accuracy: 0.1% of measured value is achieved for most application. Repeatability is to 0.01%. All meters are flow tested and have a Factory Calibration Certificate optionally fully traceable to the equivalent of UKAS standards (Austrian Calibration Service/OKD).
Ratings: Standard OMH Series meters up to 420bar.Temperature limits -20ºC to +230ºC. Special meters to 690 bar with screwed connections or wafer fitting API 6BX flanged mountings.
Viscosity Dependence: Large changes in fluid viscosity have minimal effect on meter accuracy. Independent test results on fluids of only 2 centistokes (very low) show the retention of 0.1% accuracy over a wide operating range.
OM Series: Design & Application
The Helical Screw Flowmeter accepts:
High & Variable Viscosity
Low Flow
High Pressure
High Temperature to 250°C
The Helical Screw Flowmeter provides:
High Accuracy
Reliability
Wide Range
Intrinsically-safe
Hygienic Service
OMG: Body material of grey cast iron and steel with nitrated steel rotors.
OMH: 420 bar rating, high pressure meter. Specification as OMG type but with nodular graphite cast iron body. Special variants of the design are available to 690 bar rating.
OMK: The body is stainless steel and the rotors are PTFE. The rotors run together without bearings.
Applications are: Foodstuffs such as Margarine, Honey, Jam, Fats, Oils and chocolate as well as Viscous chemicals such as Caustic Solutions, Phosphoric Acid, Polymers and Electrolyte.
OME: Low cost and compact; body material is aluminium with nitrated steel rotors.
Flange fitting: The meters can have ends prepared with a flange profile such as DIN, ANSI or other types with threads for bolts. Pipework flanges are then simply bolted to the meter. Wafer style meters are compatible with API flanges.