Wedge Type Flow Meter (WM)
+/- 4.00% Uncalibrated Uncertainty
Dirty Liquids and Slurries
- Line size: 1/2 to 30 inches
- Head loss % of Differential: 30 to 80 percent
- Recommended pipe Reynolds number: Must be greater than 5000 for basic accuracy
Reliable & Versatile Wedge Flow Meters for Demanding Applications
The WM Wedge Flow Meter from Primary Flow Signal is a differential pressure device that uses a precision-engineered V-shaped restriction, or “wedge,” to create a predictable differential pressure used to calculate flow.
Designed for flexibility across a wide range of fluids, wedge meters excel in difficult applications where other technologies may fail, including slurries, viscous liquids, dirty fluids, and flows containing suspended solids or entrained gases. Stable and accurate performance is maintained down to 5,000 pipe Reynolds, with the option of laboratory calibration for accurate measurement below this threshold. The wedge-type flow meter’s benefits also include:
- Rugged, Maintenance-Free Design: With no moving parts, wedge meters deliver extended service life and reduced maintenance requirements, even in abrasive or erosive environments.
- Durability & Longevity: The V-shaped restriction minimizes wear, resists clogging, and maintains reliable performance with slurries, suspended solids, and dirty fluids.
- Wide Turndown Capability: Stable discharge coefficient provides accurate measurement across broad flow ranges, including low Reynolds number applications (<5000 with calibration).
- Bi-Directional Measurement: Capable of measuring flow in either direction, providing versatility for complex piping systems and process conditions.
- Flexible Installation Options: Compact design can be mounted in any orientation and configured with a range of pressure connections (NPT, socket weld, or flanged).
- Customizable for Harsh Media: Hard-clad interior surfaces and a variety of construction materials, including carbon steel, extend durability for abrasive or corrosive applications.
Typical applications include chemical and petrochemical processing of corrosive or abrasive liquids, pulp and paper production involving fibrous slurries, mining and mineral processing with abrasive slurries, oil and gas refining including crude oil and multiphase streams, and high-viscosity or solids-bearing fluids across a variety of industrial plants. Wedge meters are also used in power generation, steam distribution, and other clean liquid, gas, and air services where durable, repeatable flow measurement is required.
Wedge Type Flow Meter Specifications
• Wet Calibrated: +/- 0.75
• Uncalibrated: +/- 5.00
1-30” line size:
• Wet Calibrated: +/- 0.50
• Uncalibrated: +/-3.00
Wedge Type Flow Meter Model Types
Model Types
- WMF – Wedge, Meter, Flanged
- WMT – Wedge, Meter, Threaded Ends
- WMWFR – Wedge, Meter, Wafer Ends
- WMV – Wedge, Meter, Victaulic Ends
- WMW – Wedge, Meter, Butt Weld Ends
Wedge Type Flow Meter Materials
Common Materials
- Carbon steel
- 304 / 316 stainless steel
Other Materials
- Aluminum
- Chrome Moly
- Hastelloy B & C
- Monel
- Duplex S/S
- 321S/S
- Tantalum
- Titanium
- Zirconium
Wedge Flow Meter 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
Mining, Oil & Gas
Wedge meters perform reliably in abrasive mining slurries, crude oil, multiphase streams, and gas applications. Their ability to handle suspended solids and entrained gases supports long-term accuracy across resource industries.
Power Generation & Industrial Process
Wedge meters are used for steam, gas, air, and liquid measurement in power plants and industrial processes. Durable construction and flexible installation options support reliable performance in high-pressure and high-temperature service.
Municipal Water & Wastewater
Wedge flow meters are effective for raw water, sewage, sludge, and other solids-bearing flows in municipal systems. The open V-shaped restriction resists clogging and erosion, supporting dependable influent, effluent, and wastewater measurement.
Wedge Type Flow Meter Expertise Since 1983
Proven Accuracy & Long-Term Reliability
With over 40 years of municipal and industrial expertise and more than one million Venturi installations worldwide, PFS has set the standard for dependable flow measurement. Unlike orifice plates and other short-life DP devices, our Venturi meters deliver consistent accuracy, low pressure loss, and decades of service without clogging or erosion.
Engineered Solutions & Lifecycle Support
Every system presents unique challenges, and PFS provides tailored engineering to meet them. From CFD modeling, hydraulic analysis, and laboratory calibration to start-up training and field support, our experts ensure optimized performance at every stage. Rehabilitation, recertification, and flow control integration extend meter life and maximize total value.
Certified Quality & Compliance
PFS maintains the industry’s highest quality and compliance standards, including ASME S & U, ISO 9001, and PED certifications. All products can be supplied with CRN approvals as needed, and NSF-61 certified coatings come standard for municipal and potable water applications—ensuring both regulatory compliance and safe operation.
