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Daniel Senior Dual-Chamber Orifice Fitting
With over one million Daniel™ Senior™ Orifice Fittings in service worldwide, this differential pressure flow meter reigns as the most widely used device for unparalleled measurement accuracy in accordance with AGA 3, API 14.
3 and OIML 5167. The industry-leading dual-chamber design saves time and money by providing a fast, safe and extremely simple method of changing orifice plates under pressure to prevent unscheduled downtime. A unique plate carrier ensures superior concentricity to reduce measurement uncertainty and also allows the fitting to be mounted in a vertical or horizontal plane. No need for costly bypasses or additional valves that are required with conventional orifice flanges simplifies installation and startup.

Daniel Senior Orifice Fitting - Operational Sequence of Removing an Orifice Plate Under Pressure

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Daniel Senior Orifice Fitting Demonstration

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Tutorial de Operación para el Medidor de Flujo de orificio “Senior” de Daniel

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Daniel Senior fittings slide valve for harsh environments

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Daniel Senior Dual-Chamber Orifice Fitting


Measurement Type
Differential pressure
Fluid Type
Liquid, gas
Discharge Coefficient Uncertainty
In accordance with AGA 3/API 14.3
Line Size
Line Size 2-in to 24-in (50-mm to 600-mm)
Max. Operating Pressure
ANSI 2500
Process Temperature Range
-20°F to +160°F (-29°C to +71°C )
Flange Type
ANSI Raised Face, ANSI RTJ
Process Wetted Material
Carbon Steel (WCB and LCC), 316/316L SST, Duplex
Trim Options
Standard Service, Sweet Service, Sour Service, Low Temperature


  • Regularly scheduled maintenance is critical to ensuring the longevity, reliability and performance of your system. With this program, you can keep your control system hardware and software maintenance requirements current while establishing a flexible pa
  • Minimize measurement uncertainty with unique four-point positioning system that ensures concentricity
  • Achieve custody transfer accuracy without the need for expensive flow calibration
  • Operate safely with indicator plates that clearly show if the slide valve is in the open or closed position
  • Satisfy a variety of application requirements with a wide range of line sizes and ANSI ratings available
  • Eliminate damage and/or equipment failure with a design that provides an optimal seal
  • Use with a wide variety of Daniel Universal and Paddle Type Plates and Plate Seals
  • Expedite installation with no need for costly bypasses or additional valves; mount in vertical or horizontal plane