『Asphalt Flow Meter DN200: Keeping Trunkline Pressures Steady and Reliable』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)
Asphalt Flow Meter DN200: Keeping Trunkline Pressures Steady and Reliable
Quick Answer: A DN200 oval gear flow meter with a steam or thermal oil jacket keeps asphalt trunkline pressure steady. Pressure drop stays below 0.15 bar at full flow and flow pulsation nearly disappears. This protects loading pumps, avoids relief valve trips, and gives you batch repeatability within ±0.5 percent. Send us your flow range, pipe size, and operating temperature for a technical proposal that matches your terminal.
Why DN200 Is the Right Size for Asphalt Trunklines
Asphalt at 160 °C still has viscosity between 200 and 500 cP. In a trunkline that feeds two or three loading arms, a small meter creates high backpressure and slug flow. A DN200 full-bore oval gear meter keeps fluid velocity under 1.5 m/s. That low speed keeps the flow laminar and steady, even when a second loading arm opens or closes. Most engineers skip this part, but here is the thing: velocity matters more than the meter technology when pipe size drops under DN150. We have seen this on customer sites many times. Last year a bitumen terminal in Vietnam replaced a DN100 turbine meter with a DN200 oval gear meter from Silver Instruments. Their loading pressure fluctuation dropped from ±2.5 bar to ±0.3 bar. The pump motor current became flat and operator complaints stopped the same week.
How Oval Gear Design Keeps Pressure Steady
Positive displacement meters push fluid pocket by pocket. There is no bluff body, no swirl, and no energy loss from sudden velocity changes. A heated oval gear flow meter with a DN200 housing adds a pressure drop of only 0.10 to 0.15 bar at 250 m3/h and 500 cP. Because the meter has no straight-run requirement, you can mount it right before the diverter without extra pipe length. Cold spots are the real enemy. Even a small unheated flange area can let asphalt skin over, narrow the flow path, and cause a pressure spike that trips your pump. Our DN200 meter has a full jacket that circulates thermal oil or steam up to 200 °C. The housing body and the measuring chamber stay thermally uniform. This simple mechanical design keeps the trunkline pressure trace almost silent on a 4-20 mA HART transmitter.
A Real-World Example: Asphalt Loading in Saudi Arabia
A road construction contractor in Saudi Arabia uses our DN200 asphalt flow meter for truck loading. They fill 10 000 liters per truck in under 6 minutes. Before they installed the DN200 meter, pressure surges during valve shut-off often opened the safety relief valve and splashed hot bitumen onto the drip tray. Our technical team checked the pipe size, fluid temperature, and pump curve. They recommended the DN200 oval gear meter with a PN25 body and a PGC pulse output module. After installation, loading time dropped by 20 seconds per truck because operators could keep the pump at full speed without fear of overpressure. Over six months, they recorded zero valve trips, zero meter jams, and zero downtime for cleaning. The maintenance team now only checks the PT100 temperature sensor during routine rounds.
Installation Tips That Prevent Pressure Trouble
Mount the meter in a vertical line with flow upward so any solids settle away from the gears. Use full-bore isolation valves, not reduced-port types. Always heat the meter and the adjacent spool pipe with the same jacket medium. A cold spool next to a hot meter
When You Should Upgrade from a Smaller Meter
If your control room sees pressure swings larger than 1 bar during normal loading, your meter is probably undersized. Other signs include frequent pump motor overload trips, noisy flow in the header, and batch errors that drift over a shift. Moving from a DN100 or DN150 meter to a DN200 oval gear meter is often simpler than re-piping the whole trunkline. The meter length stays within a few hundred millimeters and the flange bolt pattern fits standard pipe schedules. Before you order, send us four numbers: your maximum flow rate in m3/h, the normal asphalt temperature in °C, the pipe size at the meter location, and the pump discharge pressure. We will check pressure drop, viscosity correction, and heating requirements. In many cases, we can give a same-day technical proposal with a dimensional drawing.
FAQ
What flow meter types work best for hot asphalt?
Positive displacement meters, especially oval gear meters with heating jackets, are the top choice for asphalt. They handle viscosity up to thousands of cP, deliver pulse-free output, and do not need straight pipe runs. Coriolis mass flow meters also work but cost significantly more for a DN200 size and add pressure drop above 0.3 bar in thick fluids.
What flow range can a DN200 asphalt meter handle?
Our standard DN200 oval gear flow meter handles 20 to 250 m3/h at 160 °C with viscosity up to 500 cP. The low-flow cut-off is around 5 m3/h. For higher-viscosity pavement grades, we adjust the gear clearance to maintain accuracy and keep pressure drop low.
Does the meter need a heating jacket?
Yes. Without a jacket, asphalt can solidify inside the chamber and cause mechanical damage, high pressure drop, or a complete jam. We supply jackets for steam, thermal oil, or electric tracing, rated to 200 °C. The jacket covers the meter body and, optionally, the transmitter neck.
What pressure drop can we expect at full flow?
At maximum flow and 500 cP, pressure drop across our DN200 meter stays under 0.15 bar. That is less than half of what a turbine meter of similar size would produce because there is no obstruction. This low pressure loss keeps your trunkline pressure nearly flat from pump to loading arm.
Can we use this meter for custody transfer loading?
Yes, the DN200 oval gear meter can be calibrated to MID or OIML R117 standards with a pulse output module. Many bitumen terminals in the Middle East and Southeast Asia use it for billing. We provide factory calibration certificates traceable to ISO 17025.
Send us your pressure (bar), temperature (°C), pipe size (DN), and flow range through our website. A product engineer will reply with a dimensioned drawing, pressure-drop calculation, and a detailed quote for your trunkline.
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