Quarter Circle Orifice Plate

• ARO-QCOP-004

What is a Quarter Circle Orifice Plate ?

The Arrotop Quarter Circle Orifice Plate is a specialized flow measurement device designed for applications involving clean and viscous fluids at low velocities and Reynolds numbers. Its unique design, featuring a rounded upstream edge forming a quarter circle, ensures accurate flow measurement, particularly for low-density and low Reynolds number fluids. This orifice plate is ideal for precise flow control in challenging fluid conditions.

Product Data

Overview

Arrotop is a trusted Quarter Circle Orifice Plate manufacturer & supplier in India specializing in high-performance flow solutions like the Quarter Circle Orifice Plate. Engineered for applications involving clean and viscous fluids at low Reynolds numbers, the Arrotop Quarter Circle Orifice Plate ensures precise and consistent flow measurement. Its unique design, featuring a rounded inlet edge and a beveled outlet, reduces pressure loss while improving accuracy. Widely used in industries requiring dependable metering under moderate flow conditions, this orifice plate reflects Arrotop’s expertise as a leading flow instrumentation manufacturer in India.

The Arrotop Quarter Circle Orifice Plate is a precision-engineered differential pressure flow element designed for accurate flow measurement of clean and viscous fluids operating at low velocities and low Reynolds numbers. Unlike conventional sharp-edged orifice plates, the quarter-circle profile features a rounded upstream edge that allows smooth fluid acceleration, ensuring stable and repeatable differential pressure generation under laminar and transitional flow conditions.

This design makes the Quarter Circle Orifice Plate particularly suitable for applications where standard concentric orifice plates lose accuracy, such as in high-viscosity liquids, low-density fluids, and low flow rate systems. The smooth inlet geometry minimizes flow separation and turbulence, resulting in improved measurement reliability and reduced permanent pressure loss.

Arrotop manufactures Quarter Circle Orifice Plates in accordance with relevant international standards and best engineering practices. Each plate is precision machined and quality-checked to ensure dimensional accuracy, consistent performance, and long service life. The plates are available in a wide range of sizes, materials, and pressure ratings, with options for custom bore dimensions, plate thickness, and surface finishes to match specific process requirements.

Designed for easy integration with orifice flange assemblies and differential pressure transmitters, Arrotop Quarter Circle Orifice Plates offer a cost-effective and dependable solution for industries requiring accurate flow measurement under low Reynolds number conditions.

Features

  • Optimized for Low Reynolds Numbers : Specially designed to deliver accurate and repeatable flow measurement at low Reynolds numbers, where conventional concentric orifice plates become unreliable.
  • Viscous & Low-Velocity Fluids : Performs exceptionally well with high-viscosity liquids such as heavy oils, syrups, polymers, and chemical solutions flowing at low velocities.
  • Quarter-Circle Inlet Geometry : The rounded upstream edge (quarter-circle profile) ensures smooth flow acceleration, reducing flow separation and improving differential pressure stability.
  • Stable Differential Pressure Output : Generates a consistent and measurable pressure drop even at very low flow rates, enabling accurate measurement in challenging flow conditions.
  • Reduced Sensitivity to Flow Profile Disturbances : Less affected by upstream flow irregularities, making it suitable for installations with limited straight pipe lengths.
  • Lower Permanent Pressure Loss : Designed to minimize energy loss compared to sharp-edged orifice plates when operating under low-flow conditions.
  • High Measurement Repeatability: Provides reliable, repeatable readings over long operating periods, essential for process control and quality assurance.
  • Robust & Long-Lasting Construction : Manufactured from high-quality materials such as SS 304/L, SS 316/L, Carbon Steel, Alloy Steel, and special alloys for demanding process environments.
  • Customizable Design Options : Available in custom bore sizes, plate thicknesses, materials, and surface finishes to match specific fluid properties and process requirements.
  • Cost-Effective Solution for Low Flow Measurement : Offers an economical alternative to more complex flow meters while maintaining dependable accuracy for low-Reynolds-number applications.

Technical Information

Model NumberARO-QCOP-004
MaterialSS 304/L, 316/L, Duplex, Super Duplex, Hastelloy,
Carbon Steel, Monel, Inconel, PP, PVC, PTFE-coated,
Stellite-coated (special alloys on request)
Sizes0.5″ to 20″ (up to 48″ on requests)
Beta Ratio0.245 to 0.6
Thickness3.18 mm, 6.35 mm, 9.52 mm, 12.7 mm (other on request)
Effective RangeTypically suitable for Reynolds numbers between 250 and \(19^5ß\)
StandardsISO 5167, ASME B16.36, BS 1042, API 2530, AGA Report 3
Fluid TypesClean and viscous liquids, low-density fluids at low velocity
AccuracyWithin 1% of the maximum flow rate
Repeatability± 0.1% of the indicated flow rate
Tapping MethodsFlange Taps, Corner Taps, Radius Taps
Limit of useOrifice Diameter(d) : 15 mm, Pipe Diameter(d) : 500 mm, Beta Ratio(ß) : 0.245 to 0.6

Dimensional Data

Sizes Chart

DN (Nominal Diameter)Orifice Diameter (mm)Plate Thickness (mm)
DN15 (0.5″)153.18
DN25 (1″)253.18
DN50 (2″)506.35
DN100 (4″)1006.35
Dn150 (6″)1509.52
DN200 (8″)2009.52
DN300 (12″)30012.7
DN400 (16″)40012.7
Dn500 (20″)50012.7

Applications of Arrotop Quarter Circle Orifice Plate

The Arrotop Quarter Circle Orifice Plate is widely used in various industries for its exceptional flow measurement capabilities:

  • Chemical & Process Industries: Ideal for measuring viscous chemicals, polymers, resins, and specialty fluids at low flow rates.
  • Oil & Gas: Suitable for low-velocity liquid hydrocarbons, additives, and refined products where precision is required.
  • Power Generation: Used for low-flow steam, condensate, and auxiliary fluid measurement in power plants.
  • Water & Wastewater Treatment: Ensures reliable measurement of clean or treated fluids operating under low-flow conditions.
  • Food & Beverage Processing: Accurate metering of viscous liquids such as syrups, concentrates, and edible oils.
  • Pharmaceutical & Biotechnology: Enables precise flow measurement for clean, high-viscosity fluids in controlled process environments.
  • Pulp & Paper: Suitable for low-velocity liquid streams in chemical dosing and process control systems.

Advantages of Arrotop’s Quarter Circle Orifice Plate

  • High Accuracy: Provides precise flow measurements down to low Reynolds numbers, higher accuracy compared to conical entry orifice plates.
  • Versatility: Suitable for various clean and viscous fluids, including low-density fluids at low velocities.
  • Durability: Constructed from high-quality materials to withstand challenging fluid conditions.
  • Ease of Installation: Flexible installation options for different pipeline orientations.
  • Low Maintenance: Simple design reduces the need for frequent maintenance.
  • Cost-Effective: Offers reliable measurement at a lower cost compared to other specialized flow meters.
  • Wide Range of Sizes: Available in a range of sizes to meet diverse application requirements.
  • Customizable: Tailored solutions with various materials and coatings to handle specific process conditions.
  • Robust Construction: Engineered to handle different pressure and temperature variations.
  • Reliable Performance: Ensures consistent and repeatable measurements over time, critical for process control.

FAQS for Quarter Circle Orifice Plate

Q. What is a Quarter Circle Orifice Plate used for?

A Quarter Circle Orifice Plate is used for accurate flow measurement of clean, viscous fluids operating at low velocities and low Reynolds numbers, where standard sharp-edged orifice plates do not perform reliably.

Q. Why is a Quarter Circle Orifice Plate suitable for low Reynolds number applications?

Its rounded upstream edge (quarter-circle profile) allows smooth fluid acceleration, minimizing flow separation and turbulence. This enables stable differential pressure generation even under laminar or transitional flow conditions.

Q. How is a Quarter Circle Orifice Plate different from a Concentric Orifice Plate?

Unlike a concentric orifice plate with a sharp edge, a quarter circle orifice plate features a curved inlet geometry, making it more accurate for viscous fluids and low flow rates, while concentric plates are better suited for turbulent, high-Reynolds-number flows.

Q. What types of fluids are best measured using a Quarter Circle Orifice Plate?

Quarter Circle Orifice Plates are ideal for clean, high-viscosity fluids such as heavy oils, syrups, polymers, resins, chemical solutions, and other low-density liquids flowing at low velocities.

Q. Can a Quarter Circle Orifice Plate be used for gas or steam applications?

Yes, but it is primarily recommended for low-velocity gas or steam flows where Reynolds numbers are low. For high-velocity gas or steam, other orifice plate designs may be more suitable.

Q. What materials are used to manufacture Quarter Circle Orifice Plates?

They are commonly manufactured in SS 304/L, SS 316/L, Carbon Steel, Alloy Steel, and special alloys. Material selection depends on fluid properties, temperature, pressure, and corrosion resistance requirements.

Q. Does a Quarter Circle Orifice Plate require long straight pipe lengths?

Compared to sharp-edged orifice plates, quarter circle designs are less sensitive to upstream flow disturbances, allowing reliable operation even where straight pipe lengths are limited.

Q. What are the advantages of using a Quarter Circle Orifice Plate over other low-flow meters?

Quarter Circle Orifice Plates provide a cost-effective alternative to complex flow meters, offering good accuracy, high repeatability, simple installation, and minimal maintenance for low-flow applications.

Q. Are Quarter Circle Orifice Plates customizable?

Yes. Arrotop offers custom bore sizes, plate thicknesses, materials, coatings, and pressure ratings to match specific process and application requirements.