PD Flow Meter-Spiral Double Rotor

PD Flow Meter-Spiral Double Rotor

PD flow meter-spiral double rotor is the latest generation of positive displacement flow meter, a precision instrument used for the measurement and control of liquid flow in pipelines. It adopts a pair of special toothed spiral rotors. No pulsation, extremely low noise, high precision, high reliability, large flow rate, and strong environmental adaptability.

The flow meter is equipped with a pointer and a wheel counter, which can indicate the accumulated amount of flow. The counter with a zero device can also indicate a single accumulation. It can also output electrical pulse signals and 4-20mA analog output.

Features

  • The spiral double rotors rotate at the same speed in the metering chamber, with equal flow rate and equal rotation speed;
  • Smooth operation and extremely low noise;
  • Large flow rate and small pressure loss;
  • The spiral rotor rotates at constant speed and the fluid pulsation is small, and the signaling pulse is stable and accurate;
  • Can be configured with a variety of counters, speed regulators and external fine regulators;
  • Can be installed vertically.

PD Flow Meter-Spiral Double Rotor Technical Parameters

1. Main component materials and nominal pressure

ModelShell, front cover, back coverCover platespiral rotorshaftShaft sleeveNominal pressure (MPa)
LLT-Ecast steelcast ironCast iron, aluminum alloy, stainless steelStainless steelGraphite, rolling bearingsBelow DN100-4.0
DN150 and above-2.5
LLT-B、CStainless steelStainless steelStainless steel1.6, 2.0, 2.5
LLT-SDouble type flow meter; specifications are DN80, DN100, DN150; nominal pressure 6.3MPa, DN200 nominal pressure 4.0MPa
Remarks: LLT-C material is OCr18Ni12Mo2Ti; LLT-B material is OCr18Ni9Ti; special design can be made for special requirements.
DiameterDN25mm~DN350mm
Flow range2 ~ 1000 m³/h
Accuracy level±0.5%, ±0.2%
Display methodMechanical pointer type, LCD digital type
Connection methodFlange, thread, clamp
Signal outputPulse signal, 4-20mA signal, RS485 communication, HART protocol
Working power supply3.6V lithium battery, DC12V, DC24V
Electrical InterfaceInternal thread M20*1.5
Explosion-proof levelEx db IIC T6 Gb (LCD digital model)
Protection levelIP66
  • Accuracy level: 0.5 level, 0.2 level
  • Repeatability error: The repeatability error of the flow meter does not exceed 1/3 of the absolute value of the basic error limit of the flow meter.
  • Operating medium temperature: ambient temperature (-41℃~+50℃); Level 0.5 (-20℃~+80℃) ;Level 0.2(-20℃~+60℃); with high temperature radiator up to 250℃

2. Flow Range

Table 1, accuracy level 0.5

ModelDiameterViscosity    mPa.s
0.3~0.80.8~22~1515~400400~10001000~20002000~3500
GasolineKeroseneDiesel, engine oilHeavy oilHigh viscosity liquid
LLT-0252253~91.5~101~101~101~81~81~6
LLT-0401403~91.5~101~101~101~81~81~6
LLT-04027~203~222.5~252.5~252~182~183~12
LLT-0501507~203~222.5~252.5~252~182~183~12
LLT-05029~364.5~363.6~363.6~362.8~252.8~254.5~18
LLT-0801809~364.5~363.6~363.6~362.8~252.8~254.5~18
LLT-080220~8010~8010~10010~1006.5~566.5~565~40
LLT-100110020~8010~8010~10010~1006.5~566.5~565~40
LLT-100225~10018~10015~15015~1508.5~808.5~806.5~55
LLT-150115025~10018~10015~15015~1508.5~808.5~806.5~55
LLT-150255~22530~25025~25025~25018~15018~15010~100
LLT-200120055~22530~25025~25025~25018~15018~15010~100
LLT-200290~36050~40040~40040~40028~24028~24020~160
LLT-250125090~36050~40040~40040~40028~24028~24020~160
LLT-2502130~54065~54060~60060~60042~36042~36030~240
LLT-3001300130~54065~54060~60060~60042~36042~36030~240
LLT-3002220~800110~90095~95095~95070~60070~60054~450
LLT-3501350220~800110~90095~95095~95070~60070~60054~450

Table 2, accuracy level 0.2

ModelDiameterViscosity   mPa.s
0.3~0.80.8~22~1515~400400~10001000~20002000~3500
GasolineKeroseneDiesel, engine oilHeavy oilHigh viscosity liquid
LLT-0252253.5~83~102~102~102~82~82~6
LLT-0401403.5~83~102~102~102~82~82~6
LLT-04028~205.5~224.5~224.5~224~184~183~12
LLT-0501508~205.5~224.5~224.5~224~184~183~12
LLT-050215~369~367~367~366~256~254.5~18
LLT-08018015~369~367~367~366~256~254.5~18
LLT-080230~8020~8015~8015~8014~5614~5610~40
LLT-100110030~8020~8015~8015~8014~5614~5610~40
LLT-100240~10025~10020~12020~12018~7218~7214~55
LLT-150115040~10025~10020~12020~12018~7218~7214~55
LLT-150288~22057~22544~22044~22038~15038~15025~100
LLT-200120088~22057~22544~22044~22038~15038~15025~100
LLT-2002150~36090~36072~36072~36050~21050~21040~160
LLT-2501250150~36090~36072~36072~36050~21050~21040~160
LLT-2502180~540135~540100~540100~54090~36090~36060~240
LLT-3001300180~540135~540100~540100~54090~36090~36060~240
LLT-3002250~800220~900180~900180~900150~600150~600110~450
LLT-3501350250~800220~900180~900180~900150~600150~600110~450
Remarks: Class 0.3 and Class 0.1 flowmeters can be provided upon special request.

How does a PD flow meter work?

The PD flow meter is mainly composed of a main body, a pair of spiral rotors, a magnetic coupling, a reduction mechanism, an adjustment gear, a counter and a signaling device.

It is a volumetric flowmeter. It uses the hollow part of the spiral rotor (measuring element) and the inner wall of the metering box to form a closed cavity (see the shaded part in the figure) as the measurement chamber.

The small pressure difference between the inlet and outlet drives the rotor to rotate. At the same time, although each rotor receives different rotational moments from the fluid on the same cross-section, the resultant torque of the two rotors receiving rotational moments on all cross-sections is equal.

Therefore, the two rotors each rotate at the same speed and torque, and the displacement is balanced and pulsation-free. The spiral rotor can output 8 times the volume of the cavity per revolution.

Therefore, the rotation speed of the rotor is proportional to the cumulative flow rate of the fluid, and the rotation speed of the rotor is proportional to the instantaneous flow rate of the fluid. The number of revolutions of the rotor is transmitted to the meter counter through the magnetic coupling, which displays the flow rate flowing through the flow meter (flowing through the pipe).

PD flow meter working principle

Featured Applications

PD flow meter is a precision instrument used for measurement and control of liquid flow in pipelines.

PD Flow meters can be made of different materials and are widely used in petroleum, chemical industry, light industry, commerce, scientific research and other departments. It is especially suitable for measuring industrial liquids such as crude oil, refined oil, and light hydrocarbons.

Ship application:

The maximum displacement of the spiral double rotor flowmeter can reach 980 cubic meters/hour (customized), and it is equipped with the same filter to meet the needs of ships.

PD meter is a positive displacement flow meter. orifice meter is a differential pressure flow meter.

First, they work differently.

When the fluid passes through the PD meter, a certain pressure difference will be generated between the inlet and outlet of the flow meter. The rotating part of the flow meter (referred to as the rotor) rotates under the action of this pressure difference and discharges the fluid from the inlet to the outlet. In this process, the fluid fills the “metering space” of the flow meter again and again. Then they are sent to the exit continuously. Under given flow meter conditions, the volume of this metering space is determined. Just measure the number of rotations of the rotor. The cumulative value of the fluid volume passing through the flow meter can be obtained.

The working principle of the orifice plate meter: When the fluid fills the pipe and flows through the throttling device in the pipe, the flow stream will shrink locally, thereby increasing the flow rate and reducing the static pressure. As a result, a pressure drop occurs before and after the throttling device, that is, the pressure Difference. The greater the flow rate of the medium flowing, the greater the pressure difference generated before and after the throttling member. Therefore, the orifice flowmeter can measure the fluid flow rate by measuring the pressure difference. This measurement method is based on the law of energy conservation and the law of flow continuity.

Secondly, the main reason is that their measurable media are different. The orifice flowmeter has a wide range of applications. It can measure all single-phase flows (gas, liquid, steam) and some mixed-phase flows. PD meter is mainly used to measure liquids. Oil measurement applications are mostly used. Can be used for measuring high viscosity liquids.

  1. First of all, each pair of wheels of the oval gear is a driving wheel and a driven wheel. One wheel drives the other wheel. Collision and friction will inevitably occur, which will affect the service life. And as the use time increases, the accuracy will be affected. Impact. The two rotors of the double rotor are both driving wheels, which overcomes this shortcoming of the oval gear flowmeter.
  2. Secondly, the two rotors of the double rotor are meshed point by point. There is no noise, no friction during use, and no wear and tear with extended use time. This ensures its service life and measurement accuracy, and reduces amount of maintenance.
  3. The double-rotor flowmeter has only two clearance surfaces, while the oval gear flowmeter has 8 clearance surfaces (taking two wheels as an example). When measuring low-viscosity media, the accuracy of the two is different when measuring the same viscosity media. It is different, the double rotor is taller than the oval gear.
  4. The pulsation of the oval gear flowmeter is relatively large, while the dual-rotor one is smooth. This is determined by the measurement principle mentioned in Article 1.
  5. From a technical point of view, double rotor flowmeters, as an alternative to elliptical gears (including elliptical gears), are being used in more and more process devices that require high reliability, and have received favorable reviews.
  6. In terms of price, there is little difference between the two, especially when the diameter is larger and the material is stainless steel. Even the oval gear is more expensive than the double rotor.
  7. Compared with elliptical gears, the twin rotors are much smaller and easier to install and maintain.
  8. Compared with elliptical gears, the double rotor has good viscosity adaptability (especially suitable for chemical media).

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SI-3602 High temperature Oval Gear Flow Meter
SI-3602 High temperature Oval Gear Flow Meter
SI-3603 High Viscosity Oval Gear Flow Meter
SI-3603 High Viscosity Oval Gear Flow Meter
GF Series Gear Flow Meter
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SI-3202 Liquid Turbine Flow Meter
SI-3202 Liquid Turbine Flow Meter
SI-3203 Sanitary Turbine Flow Meter
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SI-3206 High Pressure Turbine Flow Meter
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Low Temperature Turbine Flowmeter
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Ordering Guide

When ordering, please specify the following:

  • The name of the medium being measured;
  • Flow range (m³/h): minimum, common, maximum
  • Medium temperature (℃): minimum, common, maximum
  • Medium viscosity (mPa.s): at ()℃
  • Fluid pressure (MPa): lowest, commonly used, highest
  • medium density;
  • Caliber (mm);
  • Flange requirements;
  • Accuracy requirements;
  • Sender configuration requirements:
  • Other special requirements.

PD Flow Meter-Spiral Double Rotor is a precision instrument used for the measurement and control of liquid flow in pipelines. It is a new generation of volumetric flowmeter manufactured by our company. Because it uses a pair of special toothed spiral rotors, it is also called “spiral double rotor flowmeter”.

PD Flow Meter-Spiral Double Rotor has the remarkable characteristics of no pulsation, extremely low noise, high precision, high reliability, large flow rate, and strong environmental adaptability. The double-rotor flowmeter launched by Sino-Inst supports the output of electrical pulse signals and flow analog 4~20mA signals for remote instantaneous flow indication or flow adjustment and control. It is widely used in commercial trade measurement and engineering management control in petrochemical, metallurgy, electronics, terminals and other departments.

If you need to purchase PD Flow Meter-Spiral Double Rotor, or have related technical questions, please feel free to contact us.

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    PD Flow Meter-Spiral Double Rotor for Crude Oil, Heavy Oil, Ship Trade Measurement

    PD flow meter-spiral double rotor is the latest generation of positive displacement flow meter, a precision instrument used for the measurement and control of liquid flow in pipelines. It adopts a pair of special toothed spiral rotors. No pulsation, extremely low noise, high precision, high reliability, large flow rate, and strong environmental adaptability.

    Product SKU: PD Flow Meter-Spiral Double Rotor

    Product Brand: Sino-Inst

    Product Currency: USD

    Product Price: 1599

    Price Valid Until: 2029-09-09

    Product In-Stock: InStock

    Editor's Rating:
    5