Current position > News detail
『Kral Flow Meter Catalog: High-Accuracy Three-Screw Positive Displacement Pumps and Marine Bunkering Meters』Related information(clamp on meter|electromagnetic meter|venturi meterrotameter|orifice meter|ultrasonic flow meter|mass flow meter|coriolis mass flow meter|coriolis flow meter|magnetic flow meter|magmeter flow meter|magflow flow meter|mag meter flow meter|electromagnetic flow meter|vortex flow meter|turbine flow meter|thermal mass flow meter|thermal flow meter|rotameter flow meter)
Kral Flow Meter Catalog: High-Accuracy Three-Screw Positive Displacement Pumps and Marine Bunkering Meters
Quick Answer
If you are sourcing high-accuracy three-screw positive displacement pumps or marine bunkering meters, this guide covers the practical specs and supplier checks. Silver Automation Instruments supplies positive displacement meters for fuel oil, bunkering, and process fluids with DN15 to DN150 sizes and accuracy up to 0.1%. Send us your pipe size (DN), flow range, pressure (bar), and temperature (°C) to get a quotation.
What A Three-Screw Positive Displacement Pump Actually Measures
A three-screw positive displacement pump moves liquid using three rotating screws inside a housing. The central screw drives two side screws. The cavities between the screws trap a fixed volume of liquid per rotation. This design produces very low pulsation and steady flow. For metering, the rotation count or volume per revolution is converted to a flow rate. This is why three-screw meters suit high-viscosity liquids like marine fuel oil, lube oil, and bitumen.
Typical sizes in our catalog cover DN25, DN40, DN50, DN80, DN100, and DN150. Flow range starts at 5 liters per minute for small DN25 units and goes up to 2000 liters per minute on DN150 lines. Operating pressure commonly goes to 40 bar. Temperature rating is 150 degrees Celsius with standard PTFE seals. High temperature builds can go to 250 degrees Celsius.
Marine Bunkering Meter Requirements
Marine bunkering meters need more than accuracy. They need a clean calibration chain, a pulse output for totalizer systems, and local approvals. In Singapore and Fujairah, bunker suppliers often ask for a meter factor report from the calibration lab. A customer in Vietnam needed a DN80 bunkering meter for 380 cSt fuel oil. The meter had to meet 0.2 percent accuracy on site. We supplied a positive displacement meter with pulse output, 4-20 mA HART, and a remote display. The calibration was done with ISO 8217 heavy fuel oil reference.
This is typical. A three-screw meter works well on heavy fuel oil because the screws create a continuous positive displacement. The flow profile does not depend on Reynolds number. This means a bunkering meter can hold calibration on high-viscosity oil better than a turbine meter.
Silver Automation Instruments Product Options
Silver Automation Instruments supplies three-screw positive displacement flow meters and oval gear meters for fuel oil and marine bunkering. We also supply Coriolis mass flow meters for custody transfer where density and mass measurement are required. Most customers choose a positive displacement meter when the fluid is viscous, the line size is DN25 to DN150, and they want a mechanical or pulse-only output.
Pulse output options include reed switch, NPN, PNP, and 4-20 mA HART. Electronic registers can show total volume, flow rate, bat
Kral Flow Meter Catalog and Compatibility
Many engineers search for the Kral flow meter catalog when they need a replacement for an existing three-screw pump or bunkering meter. We use the same working principle and can supply dimension-compatible models for common line sizes. The Kral brand is a known reference in marine and industrial pumping. Silver Instruments does not sell original Kral parts, but we offer an alternative positive displacement meter with the same screw pump principle. We have seen field replacements work well on diesel, heavy fuel oil, and lube oil lines.
Here is the thing. Most engineers skip this part. You should confirm the viscosity range and the pressure drop before you select a replacement meter. A three-screw meter with tight clearances can create a high pressure drop on very viscous oil. Send us your fluid viscosity in centipoise and we can check the pressure loss curve.
FAQ: Three-Screw Positive Displacement Pumps and Marine Bunkering Meters
What accuracy can I expect from a three-screw positive displacement meter? Standard accuracy is 0.2 percent of reading for viscosity above 20 cP. Laboratory calibration can get 0.1 percent on stable flow. Marine bunkering meters for custody transfer are usually calibrated to 0.2 percent or better.
What pipe sizes are available? We supply DN15 to DN150 for screw meters and oval gear meters. DN80 and DN100 are the most common marine bunkering line sizes. Smaller DN25 and DN40 units fit pilot plants, blending skids, and dosing lines.
Can this meter run with 380 cSt heavy fuel oil? Yes. The three-screw design handles heavy fuel oil, bitumen, and lube oil. You need to check temperature. Heavy fuel oil at 50 degrees Celsius can have viscosity above 380 cSt. We recommend keeping the line above 120 degrees Celsius for stable metering.
What output signals do you provide? Options include reed switch pulse, NPN pulse, PNP pulse, 4-20 mA HART, Modbus RTU, and Profibus DP. For bunkering totalizers, a pulse output with a mechanical register is common. For remote monitoring, 4-20 mA HART is easier to wire into a PLC.
What information do you need for a price quote? Send us your pipe size (DN), flow range in liters per minute or cubic meters per hour, operating pressure (bar), temperature (°C), fluid name, and viscosity in cP. We also need to know if you need a display, pulse output, or 4-20 mA HART. This lets us return a firm price within 24 hours.
Contact Silver Automation Instruments
Tel: +86-25-68650347
Whatsapp: +86-25-52155837
WeChat: +86 15365082610
Website: flow-meter.com.au