Symmetrical robust element for long-term accuracy
- No sharp edge to wear
- Handles slurries and high solids content
- Capable of bi-directional flow
Flow Measurement
Wedge Flow Meters
Robust, reliable, high performance flow solutions for difficult applications, slurries and high viscosity liquid. Better Measurement. Better Outcomes.
Overview
A differential pressure primary element for the hardest duties.
WEDGE™ flow elements utilize V-shaped restrictions to produce a square root relationship between differential pressure and volumetric flow. Elements are designed for either clean or dirty service and are offered in various materials, pipe sizes, and pressure ratings.
The flow element consists of a body and wedge flow restriction. This restriction creates a differential pressure in proportion to the square of the volumetric flow rate. The wedge restriction has no critical surface dimensions, or sharp edges, to affect measurement accuracy as the result of normally expected wear. Wedge meters can be flow calibrated and supplied with a factory calibration report, including calculations for the user’s process when such data is supplied.
Why Wedge
Engineered for slurries, solids and viscous liquids.
Accurate performance down to Reynolds number 500
- 0.5 % calibrated accuracy
- Large potential flow range
- Ideally suited to measurement of viscous liquids
Minimum upstream / downstream straight pipe needed
- Handles non-ideal installations
Primary flow element types
FPD470F
Flanged transmitter connections
2 or 3 in. RF flange (SCH 80 I.D.) transmitter connections for direct DP transmitter mounting.
FPD470C
Chemical-tee transmitter connections
Chemical-tee type with 8-hole mounting pattern, supplied with graphite gasket rated up to 340 °C (645 °F).
FPD470P
Pipe-tap transmitter connections
½, ⅜ or ¼ in. NPT pipe-tap connections for pneumatic or electronic transmitters and other DP sensing devices.
Specification
FPD470 performance and construction.
- Pipe sizes
- 15 to 600 mm (½ to 24 in.)
- Wedge ratios (H/D)
- 0.2, 0.3, 0.4, 0.5 (up to 3 in.) · 0.3, 0.4, 0.5, 0.6, 0.7 (4 to 24 in.)
- Calibrated accuracy
- ±0.5 % of actual flow (25 mm / 1 in. and larger) · ±0.75 % (15 mm / ½ in.)
- Un-calibrated accuracy
- ±5.0 % of actual flow using nominal Kd2 — applies to bi-directional flow
- Repeatability
- ±0.2 %
- Process flange connection
- ANSI Class 150, 300 and 600 raised face — additional end flange ratings on request
- Process end connections
- Wide range including ANSI and DIN flanges
- Materials of construction
- Carbon steel and 316 SST as standard, with 30+ materials available incl. 25 % Cr Super Duplex (UNS S32750), C276 Alloy (UNS N010276) and 347H stainless steel
- Internal bore
- Range of schedules and wall thicknesses; most typical is Schedule 80
- Welding
- Pressure retaining welds to ASME Section IX, meeting PED specifications with full traceability
- Instrument connection ratings
- Chemical-tee: 300 psi max. or end flange rating per ANSI B16.5 · Flanged and pipe-tap: MWP per ANSI B16.5
- PED compliance
- Calculations per PED Module H with technical file for CATII or CATIII classification
Accuracy figures are water calibrated in McMenon’s factory flow lab — refer to the calibration report supplied with each calibrated instrument. To determine H/D ratio and differential pressure, McMenon sizes each meter for your process conditions.
Key Applications
Where wedge meters earn their place.
Oil & Gas
- Coker, SRU, heavy crude, bitumen, multiphase flows
- High-pressure/high-temperature pipelines
- Abrasive media like tar sands, fracking fluids
Chemical & Petrochemical
- Highly viscous and corrosive chemicals
- Slurries with abrasive particles
- Low Reynolds number measurement
Water & Wastewater
- Sludge and biosolids measurement
- Non-clogging design for contaminated flows
- Long-term reliability in municipal systems
Mining & Slurry Transport
- Thick slurries with abrasive solids
- High-viscosity pulp flows
- Harsh, erosive process environments
Documentation
Data sheets & selection guide
Download the FPD470 wedge flowmeter data sheet with full dimensions, weights, H/D ratio tables and ordering codes (DS/FPD470–EN), plus the Selection & Practice guide, or contact our sales team for help specifying what you need.
Need help specifying?
Need a DP flowmeter for your application? McMenon can size your flowmeter and provide a complete specification. Send us your requirements or speak with our team.