SKYLINE FLOW CONTROLS INC. SFC Skyline Flow Controls Wedge Meter (SFC-WM) The SFC wedge meter is a differential pressure device for use on all fluids. It is especially designed for slurries and liquids with suspended solids. The SFC-WM is also particularly effective on highly viscous fluids. The meter can also detect pipe flow of fluids with Reynold number as low as 500. SFC-WM can also be used for bi-directional flows. Pressure tapping is available in both flanged or screwed configuration. A remote seal connection is also available for DP transmitters. Skyline Flow Controls - Wedge Meter (SFC-WM) DESCRIPTION & APPLICATIONS: Rugged and robust design Low permanent pressure loss Pipe Size: 1.5 in to 24 in (40mm to 600mm) Chemical seals available for hazardous applications Flow measurement of high viscosity liquids Flow measurement of low Reynolds number fluids Well suited for slurries applications Bi-directional flow measurement ADVANTAGES: Proven flow metering technology Rugged design which can withstand slurries and suspended solids Flow measurement with NO moving parts Low maintenance due to anti-wear and erosion preventive design Energy savings due to permanent low pressure drops 11
SFC SKYLINE FLOW CONTROLS INC. OPERATING PRINCIPLE: The SFC-WM is analogous to that of other differential producing flow meters such as orifice plates or venturi meters. The pressure difference measured across a flow constriction, or in this case a sloping "wedge" is related to the velocity of the flow passing through the narrowest cross section. Pressure taps are located both upstream and downstream from the "v" shaped constriction known as the wedge. The constriction creates a pressure drop between the upstream tap and downstream tap which is related to the velocity in the pipe line, and thus the volumetric flow rate can be obtained. The opening height of the wedge can be customized according to the amount of differential pressure required to meet within specified pressure loss. Cross-sectional View of SFC-WM For Gas: QQ = 7727 FF aa YY FF pppp (KKKK) 2 (h PP GG TT)1 2 For Steam: WW = [359 FF aa YY (KKKK) 2 ] h VV 1 2 12
SKYLINE FLOW CONTROLS INC. SFC Definition of terms Symbol Description Unit q Liquid flow rate US gpm Q Gas flow rate SCFH * W Steam flow rate lb/hr F a Expansion factor F py Gas super compressibility factor Z b Compressibility of gas at base conditions Z f Compressibility of gas at flowing conditions h Differential pressure Inches of water at 60 0 F (Kd) 2 Wedge flow coefficient G f Liquid specific gravity at flow conditions Y Gas correction factor P Process pressure Psia T Process temperature 0 R G Gas specific gravity V Volume of steam Ft 3 *Ref condition: 14.7 PSIA 60 0 F Expansion Factor Chart SELECTION CRITERION: The wedge type flow meter is an in-line differential pressure inducer with sizes range from 2" through to 24". It is generally applied to liquids with entrained air, liquids with entrained particulates, and liquids with high viscosity. The SFC-WM is highly suitable for abrasive or fibrous slurry. Fluids with low Reynolds numbers can be addressed as well with a degree of accuracy where the discharge coefficient is stable through the application range. Although accuracy, reliability, and head loss characteristics are less comparable to that of the VENTURI meters, the lower capital cost of the wedge meter is a cost effective option for highly viscous or particulate laden applications. 13
SFC SKYLINE FLOW CONTROLS INC. Dimension LL Dimension F Dimension T Approx Weight (LBS) 150 300 600 150 300 600 150 300 600 150 300 600 1.5 20.86 21.37 22.00 5.75 5.75 5.75 8.0 8.0 8.0 55 61 71 2.0 21.50 22.00 22.75 5.75 5.75 5.75 8.0 8.0 8.0 62 70 84 3.0 24.50 25.25 26.00 6.13 6.13 6.13 6.5 6.5 6.5 78 92 102 4.0 35.50 36.25 38.00 7.50 7.50 7.50 4.93 4.93 4.93 135 150 175 6.0 40.50 41.25 43.25 9.00 9.00 9.00 4.93 4.93 4.93 160 210 270 8.0 43.00 43.75 48.00 10.25 10.25 10.25 4.93 4.93 4.93 210 285 365 10.0 45.00 46.25 49.50 11.75 11.75 11.75 4.93 4.93 4.93 270 345 525 12.0 52.00 53.25 56.75 13.25 13.25 13.25 4.93 4.93 4.93 350 480 14.0 55.00 58.25 58.50 14.00 14.00 14.00 4.93 4.93 4.93 410 810 16.0 58.00 59.50 62.50 15.25 15.25 15.25 4.93 4.93 4.93 500 755 18.0 62.00 63.50 66.00 16.75 16.75 16.75 4.93 4.93 4.93 580 870 20.0 66.37 67.75 70.50 18.50 18.50 18.50 4.93 4.93 4.93 700 1100 24.0 73.00 74.25 77/50 21.00 21.00 21.00 4.93 4.93 4.93 955 1310 Line Size (INCHES) 14
SKYLINE FLOW CONTROLS INC. SFC INSTALLATION INFORMATION AND REQUIREMENTS: The SFC-WM does not require specific installation requirements as it is relatively forgiving and will operate properly under most conditions. Nevertheless, to achieve the best results, the recommended installation guidance below should be observed and incorporated. The adverse effects arising from improper installation can include plugged impulse lines or tap holes, entrapped air/gas in the taps or impulse lines, and introduction of a minor hydrostatic head effect (in a vertically orientated installation) or discharge coefficient shift. Meter Orientation A, which is the horizontal orientation of the wedge, is preferred and typical for most installations and operations. ORIENTATION REQUIREMENTS The SFC-WM can be rotated between 45 o to 90 o. The resulting tap locations will allow any undissolved solids to easily pass beneath the wedge. This prevents build-up and also minimizes air or gas entrapment at tap locations. Meter Orientation A Vertical installations of SFC-WM may result in a hydrostatic head effect due to the elevation difference of the individual impulse lines. This must be corrected by adjusting and calibrating the transmitter to achieve the best results. Other orientations and installations are permissible provided that adequate considerations and accommodation are made by virtue of proper venting and compensating for relative differences in tap elevations. 15
SFC SKYLINE FLOW CONTROLS INC. REQUIREMENT FOR STRAIGHT PIPE-RUN Like most flow meters, straight or unrestricted pipe-run upstream and downstream of the flow element is preferred, and will produce better results and accuracy. By providing adequate straight line piping upstream and downstream of the meter, it can significantly increase accuracy despite the presence of disturbers. General guidance is offered in the table below with all dimensions provided being considered from the apex of the wedge element. RECOMMENDED UPSTREAM AND DOWNSTREAM STRAIGHT-LINE TABLE Upstream Disturber Preferred Diameters Minimum Diameter Partially Opened Gate Valve 10 5 10 3 Concentric Increaser 10 5 5 3 Concentric Reducer 10 5 5 3 1 Elbow 10 5 5 3 2 Elbow Close Coupled in Plane 10 5 5 3 2 Elbow Close Coupled out of Plane 10 5 10 3 16