Orifice Plates

OP Orifice Plates

Flow Measurement / Flow Restriction
+/- 0.5-0.75% Uncalibrated Uncertainty
Liquids and Gases, Lower Cost

  • Line size: 1/2 to 40 inches
  • Meets ISO, AGA, ASME, API requirements
  • Recommended pipe Reynolds number: Greater than 10,000 basic accuracy


Orifice plates are common differential producer type flow elements for the measurement of liquids, gases and steam flow. Orifice plates are used for measuring and controlling fluid flow and can also be used to reduce pressure in a pipe system. The concentric, square edge type of orifice plate is the most frequently used, offering low cost, accuracy, ease of installation and rapid availability.


Line Size
½” to 48” Standard (special sizes available)
Head loss % of Differential
30% to 70% Beta Dependent
Basic Accuracy (% of Total)
+/- 0.25 (Calibrated) +/- 0.50% to 0.75%, Beta Dependent (Uncalibrated)
Minimum pipe Reynolds number
Must be greater than 10,000, Added uncertainty under 10,000
Required Straight Piping
Per ISO, AGA, ASME, API standard as applicable, 5 to 70 Pipe Diameters
Beta Range
0.20 to 0.75
Useful Service Life
Long, Check Periodically if Erosive Fluid is a Concern
Service Functional Limits
Clean liquids & gases
Vent or Drain Holes
Vent or drain holes are available to let trapped gas or condensate pass

Support and Service

In addition to a wide range of differential producing Venturi flow meters, orifice plates, WedgeType™ flow meters, and open channel flow elements, PFS provides comprehensive, specialized services for new and existing flow meters, including rehabilitation, hydraulic analysis, and full engineering support.


ISO 9001, ASME S&U, PED Certified, CRN.

See all certifications