Classical Venturi (CV)
± 1.0% to 1.5% Uncalibrated Uncertainty
Clean Liquids & Gases
- Line Size: 2” to 48”. Larger sizes available.
- Head Loss % of Differential: 10 to 25 percent
- Recommended Pipe Reynolds Number: Greater than 200,000
Industry-Leading Classical Venturi Meters
The classical Venturi flow meter is a proven differential pressure measurement device engineered for long-term accuracy, stability, and low permanent pressure loss. Its smooth converging section, precision-machined throat, and controlled diffuser geometry make it well suited for clean liquids, gases, and steam applications—particularly where pressure recovery and reliability are critical.
Classical Venturi meters operate by increasing fluid velocity through the throat and measuring the resulting differential pressure between the inlet and constricted section. This simple, robust design provides excellent repeatability, low susceptibility to erosion, and enduring measurement performance across a broad range of operating conditions.
Key Advantages of the Classical Venturi:
- Design Stability & Proven Performance: Delivers consistent accuracy under high-Reynolds-number flow, with repeatability of ±0.1% and uncalibrated accuracy ranging from ±1.00% to ±1.50%.
- Extremely Low Permanent Pressure Loss: Recovers up to 75–90% of differential pressure, reducing operating energy costs compared to orifice plates and flow nozzles.
- Durable, Long-Life Construction: No moving parts and a geometry less prone to wear extend service life in demanding environments.
- Wide Turndown Capability: Supports turndown ratios of 10:1, 20:1, 50:1+, depending on meter configuration and secondary instrumentation.
- Flexible Installation: Can be mounted in any orientation; PFS provides guidance on upstream and downstream piping requirements based on application.
- Standards & Compliance: Designed in accordance with ASME MFC-3M, ISO 5167-4, and ASME PTC 19.5. Optional NSF-61 potable water–approved coatings are available upon request.
Typical applications include steam and water systems, hydrocarbon liquids and gases, water treatment and distribution, chemical and petrochemical processes, oil refining and production, and high-velocity industrial process flows.
Classical Venturi Specifications
Industrial: Dirty fluids if equipped with rem seals
Uncalibrated: ± 0.75% to 1.50% beta dependent
Consult PFS for lower Reynolds use.
Classical Venturi Model Types
Model Types
- CVE – Classical, Venturi, Eccentric
- CVF – Classical, Venturi, Flanged
- CVW – Classical, Venturi, Butt Weld Ends
- CVI – Classical, Venturi, Insert
Classical Venturi Materials
Common Materials
- Carbon Steel
- Stainless Steel
- Chrome Moly
Other Materials
- Aluminum
- Monel
- Tantalum
- Zirconium
- Hastelloy
- Titanium
- Duplex S/S
- 321 SS
Classical Venturi 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.
PFS maintains the following certifications, standards & compliances:
- ISO 9001
- AGA
- ASME S & U
- API
- ANSI
- European Pressure Equipment Directive (PED)
Applications
Water & Steam Systems
By far the most common use case for classical Venturi meters. They are heavily used across municipal water treatment and distribution networks as well as industrial steam and water utility systems. Their low permanent pressure loss, high accuracy, and long-term reliability make them ideal for raw water intakes, treatment plant influent/effluent, distribution mains, boiler systems, district energy loops, and general plant utilities.
Oil & Gas – Production & Refining
This combined category captures the full oil & gas lifecycle: production, gathering, separation, gas and liquid pipelines, and refining operations. Classical Venturi meters are valued here for their stable DP measurement, low permanent pressure loss, and ability to operate dependably under high pressures, high velocities, and clean-service conditions.
Chemical & Petrochemical Facilities
Used widely for clean liquids, gases, and steam in continuous-duty chemical processes. While significant, the volume of installations is generally lower than in water/steam or oil & gas applications.
High-Velocity Industrial Processes
A relevant but more situational category. These applications commonly overlap with other industries and involve high-energy flow conditions where Venturi meters maintain accuracy and minimize erosion.
Classical Venturi Flow Meter Expertise Since 1983
Proven Performance in Liquid, Gas & Steam Measurement
For more than 40 years, PFS has specialized in precision flow measurement using Venturi technology. Our Classical Venturi meters provide the reliable accuracy, low head loss, and long service life expected from true ASME/ISO designs—making them a preferred solution for municipal water systems, industrial utilities, steam distribution, and clean hydrocarbon processes. With no moving parts and a smooth, erosion-resistant geometry, the Classical Venturi delivers stable, repeatable measurement even under high-velocity or high-temperature operating conditions.
Engineering Guidance for Optimized Meter Selection
Every flow system presents unique hydraulic challenges, and PFS engineers work closely with operators to ensure the meter is properly sized and configured for the application. From throat design optimization and beta-ratio selection to piping recommendations, calibration support, and instrumentation integration, each Classical Venturi is engineered for its exact operating envelope. PFS also offers refurbishment and verification services, helping extend meter longevity and protect accuracy over decades of operation.
Standards-Driven Manufacturing & Compliance
Classical Venturi meters from PFS are manufactured under rigorous quality programs, including ASME S & U certifications, ISO 9001 compliance, and PED accreditation. Designs are available to meet ASME MFC-3M, ISO 5167-4, and ASME PTC 19.5 requirements, ensuring accurate, standards-based performance for regulated municipal, industrial, petrochemical, and refining applications. When required, PFS can also supply meters with Canadian Registration Numbers (CRN) to meet regional pressure-equipment regulations.
