Venturi Nozzle
± 1.21% to 1.74% Uncalibrated Uncertainty
Liquids and Gases, Lower Loss
- Line Size: 2.5” to 20”
- Head Loss % of Differential: 5% to 20%
- Recommended Pipe Reynolds Number: Greater than 150,000
Venturi Nozzle for Lower-Loss Flow Measurement in High-Velocity and Steam Applications
The PFS Venturi nozzle is a hybrid differential pressure flow element that combines the inlet geometry of an ISA 1932 nozzle with an outlet section similar to a Venturi tube. This design places the low pressure tap in the throat and delivers lower permanent pressure loss than traditional ISA 1932 and long radius nozzles, while maintaining stable performance in demanding services.
Because it does not rely on a sharp edge to maintain accuracy, the Venturi nozzle offers excellent long-term measurement stability with reduced wear and lower susceptibility to distortion over time. It is commonly selected for liquid, gas, and steam flow measurement in high pressure, high temperature, erosive, and high-velocity applications, including power plant environments where reliability and repeatability are critical.
Venturi Nozzle Benefits & Features:
- Lower Permanent Pressure Loss: Hybrid nozzle and Venturi diffuser design reduces loss compared to equivalent ISA 1932 and ASME long radius nozzles.
- Stable, Long-Term Accuracy: No sharp edge to wear or distort, helping maintain measurement performance over time in demanding services.
- Built for Tough Applications: Well suited for steam, high pressure and temperature flow, high-velocity service, and erosive or non-viscous media.
- Long Service Life, Low Maintenance: No moving parts means fewer failure points and reduced upkeep.
- Repeatable, Flexible Performance: Repeatability of ±0.1%, with turndown ratios of 10:1, 20:1, 50:1 and greater depending on design and instrumentation.
- Installation Flexibility: Mounts in any position to accommodate piping layout constraints.
- Designed Around Recognized Standards: Aligns with common ASME and ISO nozzle-related design and construction expectations (as applicable).
Construction Standards
ASME Section I
ASME B31.1 Power Piping
ASME B31.3 Process Piping
Design Standards
ASME PTC-19.5
ASME MFC-3M
ISO-5167
Venturi Nozzle Specifications
Uncalibrated: ± 1.21% to ± 1.74% beta dependent
Greater can be achieved depending on the specific model and design of the meter as well as the type of secondary instrumentation system utilized
Venturi Nozzle Materials
Typical material selections for standard applications:
- Carbon Steel
- 304/316 Stainless Steel
- Chrome Moly
Other options for material selection:
- Aluminum
- Zirconium
- Hastelloy B&C
- Monel
- Duplex SS
- 321 SS
- Titanium
- Tantalum
Venturi Nozzle Certifications
PFS is a contributor to various international standards committees, fully supporting our staff’s memberships to these commissions.
Individual products follow relevant industry regulations, including requirements specific to the oil and gas, water/wastewater, and power generation industries.
Note: Several international codes govern use and design of flow nozzles, ASME, ISO and others. While they cover similar meter embodiments, design parameters and requirements, stated performance in key areas they may differ.
PFS maintains the following certifications, standards & compliances:
- ISO 9001
- AGA
- ASME S & U
- API
- ANSI
- European Pressure Equipment Directive (PED)
Applications
Power Generation
Venturi nozzles are widely used in power plants for steam and feedwater measurement where high pressure, high temperature, and repeatable performance are required. Their lower-loss design helps support efficiency, while long-term stability makes them a strong fit for performance-critical measurement points.
Oil & Gas
In upstream, midstream, and downstream operations, venturi nozzles provide dependable differential pressure measurement for clean hydrocarbon liquids and process gas service. They are well suited for pressurized piping in production, refining, and gas processing environments where durability and predictable results matter.
Industrial Process
Across industrial facilities, Venturi nozzles are used in clean gas and liquid process lines where flow measurement supports control, reporting, and equipment protection. Their robust construction performs well in high Reynolds number service and in high-velocity lines common in heavy industry and process manufacturing.
Water & Utilities
Venturi nozzles are used in water treatment and distribution applications for reliable measurement of clean water flows. They are a practical option for plants that want stable DP performance with lower pressure loss and minimal maintenance demands.
Industry-Leading Venturi Nozzle Supplier Since 1983
Four Decades of Proven dP Flow Expertise
PFS has over 40 years of experience designing differential pressure flow elements for demanding liquid, gas, and steam service. The Venturi nozzle is trusted in high pressure, high temperature, and high velocity applications where durability, low loss, and long-term measurement stability matter.
Responsive, Expert Engineering Support
From sizing and beta selection to tap location guidance and instrumentation recommendations, PFS provides practical engineering support to help you apply the Venturi Nozzle correctly. The goal is reliable, repeatable flow data that holds up in real operating conditions and supports your performance and reporting needs
End-to-End Manufacturing & Quality Control
PFS provides in-house machining and fabrication with controlled procedures and documentation to support consistent builds. When calibration or verification is required, our team can support test planning and documentation so the nozzle integrates smoothly into your measurement program.
