Suitable for use in a variety of fluid systems.

Transcription

1 Suitable for use in a variety of fluid systems. General Description Pipeline Wye Strainers are in thousands of applications in chemical, petroleum, pulp and paper, and utilities, as well as numerous commercial and institutional locations. These strainers have been designed following time tested principles to conform to applicable codes and standards such as Power Piping ANSI B31.1. They have successfully passed stringent shock and vibration tests. Body materials and end connections conform to recognized standards. Screens are stainless steel or Monel. Spark-plug-like, clad, non-asbestos gaskets are used to provide reliable sealing with minimal loading. Screens are guided, not crushed, into bodies, caps and covers for confident particle retention. Applications The Pipeline Wye Strainers are suitable for use in a variety of fluid systems such as air, chemical, condensate, gas, oil, petroleum or water lines, for the protection of valves, pumps, compressors, condensers, flow meters, nozzles, steam traps and other vulnerable equipment. -US-0909

2 Features and Benefits Body material ASTM and/or ASME as permitted under Boiler Code and Power Piping Code. Provides assurance of quality and suitability for pressure/temperature adjustment in non-shock service. Straight threads on cap for easy removal when screen replacement is necessary. Clad, non asbestos, spark-plug-type gasket provides reliable seal on machined body and cap. Guided screen screens fit into controlled machined bores in body and cap, and are not crushed. This fit provides good screen alignment and reliable capture of particles. Installation can be installed in vertical and horizontal piping with the blowdown connection oriented in any preferred direction. Design meets ANSI B31.1. Conforms to recognized codes and standards for assurance of quality. Installation Strainers should be installed upstream of pipeline equipment to protect against damage from solid particles of dirt, chips, scale, packing shreds, pipe sealants and welding debris. The strainer should be fitted with a pipe nipple in the cap or cover and a full ported straight through valve (e.g., gate or ball). Install the strainer in a horizontal or vertical line with flow in the direction of the arrow. For freeze protection, install the strainer on its side or upside down in a horizontal line or vertically to assist in draining the blowdown line and strainer cavity. Inspect the strainer regularly. Clean the screen before it becomes more than one-third clogged. Pressure gages before and after the strainer will indicate excessive pressure losses due to clogging. How to Select There are three important components in selection: 1. Design and operating pressures and temperatures look at the curves in Figure 2. Select the strainer rating that meets both the design and the operating requirements. 2. Flow rate and pressure drop select a strainer pipe size that will yield a pressure drop of 1 1 /2 psi or less. This will accommodate increases in pressure drop due to dirt or alternate screens without causing the screen to rupture. 3. Look at the selection table on page 4 and pick the strainer series that meets the conditions of 1 and 2 above, and is compatible with the flowing medium. 2

3 900 Series, Threaded Cap Straight through design. Minimum pressure drop. Full draining. Proper screen retention and alignment for reliable capture of particles. ANSI Class Rating for non-shock pressure/temperature adjustment. Straight machine threads in body and on cap for ease of removal. Generously sized, corrosion resistant screen for most applications. Machined body and cap, metal clad non-asbestos gaskets for reliable seal. 800 and M800 Series, Bolted Cover ANSI Class flanges. Generously sized, corrosion resistant screen for most applications. Blow-off connection. Machined surfaces, non-asbestos gasket and bolted cover for reliable seal. 3

4 Threaded Socketwelding and Flanged Strainers Materials End Connection Threaded Cap Strainer and Nominal 900 Series Available Figure ANSI Class Bolted Cover Screen Type Pipe Sizes Number Ratings 1 Body M800 Series Gasket and Material 2 in. [DN] 901 M801 M804 M M SW M831 M828 M838 M822 M832 M824 Threaded B16.4 Cast Iron Carbon Steel Copper Clad 1/32" Perf. 3/8" to 2" CL 250 A-278 CL 35 Non-Asbestos 18-8 SS [10-50] Threaded B16.4 Cast Iron Cast Iron 3/64" Perf. 2 1 /2" to 3" CL 250 A-126 CL B A-126 CL B Non-Asbestos 18-8 SS [65-80] Flanged F.F. B16.1 Cast Iron Carbon Steel Non-Asbestos 1 1 /2" to 8" CL 125 A-126 CL B A-36 3/64" Perf. 5" to 8" 18-8 SS [40-200] Flanged 1 /16" RF Cast Iron 1 1 /2" to 8" B16.1 CL 250 A-126 CL B Carbon Steel Non-Asbestos 3/64" Perf SS [40-200] Threaded B Cast Steel Carbon Steel SS Clad 1/32" Perf. 1/2" to 2" CL 600 A-216 WCB Non-Asbestos 18-8 SS [6-50] Threaded B Cast Steel Cast Steel Spiral Wound 1/32" Perf. 2 1 /2" to 3" CL 600 A-216 WCB A-216 WCB Non-Asbestos, SS 18-8 SS [65-80] Socketwelding Cast Steel Carbon Steel SS Clad 1/32" Perf. 3/8" to 2" B16.11 CL 600 A-216 WCB Non-Asbestos 18-8 SS [10-50] Socketwelding Cast Steel Cast Steel Spiral Wound 1/32" Perf. 2 1 /2" to 3" B16.11 CL 600 A-216 WCB A-216 WCB Non-Asbestos, SS 18-8 SS [65-80] Flanged 1 /16" RF Cast Steel Cast Steel Non-Asbestos 1/32" Perf SS 1/2" to 1 1 /2" B16.5 CL 150 A-216 WCB A-216 WCB [15-40] Flanged 1 /16" RF Cast Steel Cast Steel 1/32" Perf. to 4" 18-8 SS 2" to 8" B16.5 CL 150 A-216 WCB A-216 WCB Non-Asbestos 3/64" Perf. 5" to 8" 18-8 SS [50-200] Flanged 1 /16" RF Cast Steel Cast Steel Non-Asbestos 1/32" Perf SS 1/2" to 1 1 /2" B16.5 CL 300 A-216 WCB A-216 WCB [15-40] Flanged 1 /16" RF Cast Steel Cast Steel 1/32" Perf. to 4" 18-8 SS 2" to 8" B16.5 CL 300 A-216 WCB A-216 WCB Non-Asbestos 3/64" Perf 5" to 8" 18-8 SS [50-200] Flanged 1 /4" RF Cast Steel Cast Steel Spiral Wound 1/32" Perf. to 4" 18-8 SS 2" to 8" B16.5 CL 600 A-216 WCB A-216 WCB Non-Asbestos, SS 3/64" Perf. 5" to 8" 18-8 SS [50-200] Notes: 1. See Chart, Figure 2 (page 10) for pressure/temperature ratings. 2. See page 11 for optional screen materials and openings. 4

5 How to Specify Threaded Cap Body shall be Wye-Type. Threaded cap shall have straight machined threads for easy removal. Body and cap shall have machined surfaces for metallic clad, non-asbestos gaskets. Strainer screen shall fit into non-tapered machined bores. Thread end strainers shall be machined to ANSI B Socketwelding ends shall be to ANSI B16.11; flanged ends shall conform to ANSI B16.4 (iron) or B16.5 (steel). Bolted Cover Body shall be Wye-Type. Covers shall be bolted for easy removal. Body and cover shall have machined surfaces for non-asbestos gasketing. Screen shall fit into non-tapered, machined bores. Strainer ends shall conform to ANSI B for threads, ANSI B16.11 for socketwelding. How to Order Specify pipe size, series and pipe connection. Example: 3 /4", Series 921, NPT ends. Figure 1: Water Flow vs. Pressure Drop Flow Rate, m 3 /hr /8", 1 / /4" " /4" /2" " Pressure Drop, psi C v 1/2" - M800 3/4" - M800 1" - M /4" - M /2" - M800 2" - M /2" - M800 3" - M800 4" - M800 5" - M800 6" - M800 8" - M Pressure Drop, bar C v = GPM Flow Rate, gpm water DP S.G. S.G. = Specific gravity Clogged Screens This chart represents the results of tests conducted with strainers containing clean screens. With screens 50% clogged, pressure drop results are approximately double those shown in charts. Multiplying Factor All results are based upon the use of dia. through 1 /4" dia. perforations. When using.020 perforations, multiply pressure drop from graph by For mesh lined perforated metal screens, multiply pressure drop by

6 Pressure drop through Wye strainers In the application of Wye strainers, the most frequent concern is pressure drop. Since the strainers can have a variety of fluids passing through them, there are a variety of equations and conditions that affect the flow. Our objective is to present methods for calculating pressure drops across s Wye Type strainers. The calculations are based on a series of formulas and the use of a C v, and covers liquids, steam and gases. The following assumptions are made: 1. Control valve equations and the use of C v is appropriate. 2. For liquid flow: Flashing and cavitation are not present. There is no significant change in density. Flow is fully turbulent and viscosity is not a significant factor in the calculations for pressure drop. 3. For steam, gas and air flows, pressure drops are not critical, and a change in density (if it occurs) is not significant. The examples of pressure drop calculations are based on new, clean strainers. If clogged screens are a significant concern, follow the footnote under Figure 1. Determine the strainer C v The first thing to determine is the strainer C v. This can be obtained from Figure 1 the water flow vs pressure drop curve where C v = gpm when the pressure drop is one (1) psi. Example: What is the C v for a 3" M800 Wye strainer? Solution: 1. Enter the left, vertical axis at one (1.0) psi. 2. Move horizontally to the right until you reach the 3" M800 curve. 3. Then, move vertically down and read 150 gpm. 4. Answer - The C v for a 3" M800 is 150. This solution is for water; specific gravity is approximately one. Liquid flow with specific gravity not equal to one Example: What is the pressure drop if the fluid is kerosene, flowing at 150 gpm for a 3" M800 strainer? Solution: 1. Enter a table of various liquids. 2. Find kerosene with a specific gravity of Solve the equation Equation 1: DPI = G ( V I ) 2 C v = (0.82)( 150 ) 2 = 0.82 psi 150 Where: DPI = Liquid/pressure drop, psi VI = Liquid flow, gpm = 150 (previous example) C v = Strainer C v = 150 (previous example) GI = Specific gravity of liquid. For kerosene GI = 0.82 Liquid flow, viscosity consideration With the turbulent flow, the pressure drop equations are independent of Reynolds Number. When viscous fluids are present, Reynolds Numbers can be changed to the point where Laminar flow is achieved. The use of Equation 2 and 3 determines if the flow is turbulent. If it is turbulent, Equation 4 can be used. If Reynolds Number is less than 4000, Equation 4 will predict a greater than expected pressure drop. Equation 2: Re = 3160 VI vd Re = Reynolds No. VI = GPM v = Kinematic viscosity, centistokes Equation 3: VI = C v DP v GI GI = Specific gravity of liquid DP v = Viscous fluid, pressure drop, psi d = Pipe I.D. inch Combining Equation 2 and 3 and assuming Re = 4000 minimum for turbulent flow, and d is a controlling factor for the strainer: 4000 = (3160) ( C v ) DP v vd GI or Equation 4: DP v = (1.6023)(GI) ( vd) 2 C v Example: Assume the same 3" strainer flowing kerosene. The specific gravity is 0.82, but the kinematic viscosity is Pipe I.D. is inches. Using Equation 4: (2.69 x 3.068)2 DP v = (1.6023)(0.82) 150 = psi minimum for a Reynolds Number of 4000 to maintain turbulent flow. This means that if the pressure drop and Reynolds Number are too low, Laminar flow may result and the influence of viscosity can alter the results. The approximate Reynolds Number for 150 gpm flow in the example is: (3160) (150) Re = (2.69) (3.068) is over 57, 400 from equation (2) and the DP v approaches 0.82 from equation (3). 6

7 Gas and Vapor Flow The flow of gases and vapors is more complicated than liquid flow. This is due to changes in density. If pressure drops are too great, the nature of the gas or vapor changes. These equations are assumed to apply: In the above, it is assumed that the control valve formulas for non-critical steam and gas flow are applicable. DPs = Pressure drop across strainer, steam psi DPg = Pressure drop across strainer, gas, air, etc. P 1 = Strainer inlet pressure, psia W = lb/hr steam flow Q = SCFH gas flow T s = Degrees F superheat above saturation T = Degrees R gas temperature (F+ 460) G = Specific gravity, gas (air = 1) Steam (Saturated or Superheat) Equation 5: DP s = P 1 - (P 1 ) 2 - (W) ( T s ) 2 (2.1) (C v ) Gases (Including Air) Equation 6: DPg = P 1 - (P 1 ) 2 -(G) (T) (Q) 2 (963) (C v ) Saturated Steam Flow Let s assume we have a 2" steam line. Steam flow is 2000 lb/hr and the steam pressure is 100 psig, saturated. What is the pressure drop through the 2" 921 Wye Strainer? From Figure 1 we see that the 2" 921 has a C v equal to 55. P 1 = 100 psig = 115 psia W = 2000 lb/h C v = 55 T s = 0, because the steam is saturated From Equation 5: DPs = (115) - (115) 2 - = 1.31 psi drop (2000) (1 + 0) 2 (2.1) (55) The steam pressure drop is calculated to be 1 to 1 1 /2 psi. Superheated Steam Assume the same strainer and conditions as for saturated steam, except the steam temperature is 500 F. We use the same equation except T s = T s = 162 F, degrees superheat 500 = Steam temp, F 338 = Sat. temp, F for 100 psi DP s = (115) - (115) 2 - DP s = 1.63 psi (2000) ( x 162) 2 (2.1) (55) The superheated steam will produce a pressure drop nearly 1 /4 more than the saturated condition. Gases If we keep the same strainer, but now consider natural gas flow at 50,000 SCFH and at a temperature of 100 F. C v = 55 P 1 = 115 psia G=0.667 T= = 560R Q=50,000 DPg = (115) - (115) 2 - (0.667) (560) 50,000 2 (963) (55) = 1.46 psi Pressure drop is approximately 1 1 /2 psi. 7

8 Easily Removable Screen Caps Straight threads permit easy removal from the strainer body when the screen must be cleaned, and assure proper alignment of the screen when re-assembled. Machined faces and spark plug type gasket provide a good joint without excessive tightening. On 2 1 /2" and 3" strainers, four bolt covers are used instead of threaded screen caps. Dimensions, in. [mm] Strainer 901, M , 921 SW Size M821, M831 in. [DN] A B A B 3/8 3 1 /8 2 5 / / /32 [10] [80] [55] [84] [55] 1/2 3 1 /8 2 5 / / /32 [15] [80] [55] [84] [55] 3/4 3 5 / / / /32 [20] [92] [63] [97] [63] /8 3 1 / / /32 [25] [111] [77] [116] [77] 1 1 / / /8 4 9 /32 [40] [152] [109] [156] [109] /8 5 7 / /2 5 7 /32 [50] [181] [133] [191] [133] 2 1 /2 9 1 /4 5 7 / /8 [65] [234] [149] [305] [238] /8 [80] [254] [152] [305] [238] Threaded and Socketwelding Strainers B A Series 901, 921 and 921SW, threaded, socketwelding ends (with threaded screen caps). A C 45 B 45 Weight, lb. [kg] Strainer Size Strainer Weights in. [DN] , 921SW M801 M821, M831 3/ /2 [10] [0.5] [0.7] 1/2 1 1 /4 1 1 /2 [15] [0.6] [0.7] 3/4 1 1 /2 2 [20] [0.7] [0.9] /2 [25] [1.4] [1.6] 1 1 /2 6 1 /2 7 1 /4 [40] [2.9] [3.3] /4 13 [50] [5.1] [5.9] 2 1 / [65] [10] [19] [80] [13.6] [19.6] Notes: 1. Series M800 strainers. Threaded inlet, outlet and blow-off connections are NPT standard; socketwelding connections are machined to ANSI standard. 2. Threaded blow-off connection standard. Contact your sales representative for optional sizes and socketwelding. Standard Blow-off Connections, Dimension C 2 Series 900, M801, M821 and M831 Strainer Size, Connection NPT, in. [DN] in. [DN] 3/8 to 1 /2 3/8 [10-15] [10] 1 1/2 [20-25] [15] 1 1 /2 to 2 3/4 [40-50] [20] 2 1 /2 to 3 M801 [65-80] 1 1 /2 [40] 2 1 /2 to 3 M821, M831 [65-80] 1 1 /4 [32] Note: Contact your sales representative for optional sizes and socketwelding. Series M801, M821, M831 threaded end. C 8

9 M Series flanged end strainers are furnished with bolted covers. Standard materials are cast iron and carbon steel, in sizes 1 /2" to 8". Dimensions, in. [mm] Strainer M804 M806 M804 M806 M804 M806 M804 M806 M828 M822 M824 M828 M822 M824 M828 M822 M824 M828 M822 M824 Size Ratings & M838 & M832 & M838 & M832 & M838 & M832 & M838 & M832 in. [DN] 1 A A B B C C D D A A A B B B C C C D D D 1/2 5 7 /8 6 1 /8 6 5 /8 3 1 /2 3 1 /2 3 1 /2 3/8 3/8 3/ [15] [149] [155] [168] [89] [89] [89] [10] [10] [10] [130] [130] [130] 3/4 7 3 /8 7 3 /4 8 5 / /4 3 3 /4 3 3 /4 1/2 1/2 1/ [20] [187] [197] [211] [95] [95] [95] [15] [15] [15] [130] [130] [130] /8 7 7 /8 8 5 / /4 3 3 /4 3 3 /4 1/2 1/2 1/ [25] [187] [200] [211] [95] [95] [95] [15] [15] [15] [130] [130] [130] 1 1 /2 7 1 /2 8 1 / /4 4 3 /4 1/2 1/2 6 1 /2 7 1 /8 8 1 / /4 4 3 /4 4 3 /4 5 1 /2 1/2 1/2 1/ [40] [190] [204.8] [120] [120] [15] [15] [165] [181] [194] [260] [121] [121] [140] [15] [15] [15] [178] [178] [203] /8 9 5 / /4 6 1/2 1/ /8 8 5 / /4 5 1 /4 7 1/2 1/2 1/ [50] [200] [236.5][133.3][152.4] [15] [15] [178] [200] [219] [279] [133] [133] [178] [15] [15] [15] [178] [178] [254] 2 1 / / /2 7 1 / /4 9 3 / / /2 6 1 /2 8 1 / /4 9 3 / /2 [65] [254] [280.9] [165] [181] [25] [25] [248] [248] [269] [305] [165] [165] [210] [25] [25] [25] [248] [248] [318] / / / / / / / / /2 [80] [257.1][320.7] [178] [232] [25] [40] [254] [256] [305] [343] [178] [178] [235] [25] [25] [32] [254] [254] [368] / /8 8 1 / /8 1 1 /2 1 1 / / / / /4 8 1 / /2 1 1 /2 1 1 /2 1 1 / /2 [100] [307.9][396.9] [210] [276] [40] [40] [305] [308] [368] [456] [210] [210] [318] [40] [40] [40] [305] [305] [495] / / / / / / / / / [125] [396.8][463.5] [286] [329] [50] [50] [432] [397] [491] [565] [286] [343] [381] [50] [50] [50] [508] [508] [584] / / / / / / / / / [150] [469.9][512.7] [343] [368] [50] [50] [508] [470] [491] [651] [343] [343] [508] [50] [50] [50] [508] [508] [787] / / / / / / / / / / / / /2 [200] [549.2][638.1] [394] [418] [50] [50] [578] [543] [594] [806] [394] [400] [610] [50] [50] [50] [578] [578] [978] Flanged Strainers A Weight, lb. (kg) Strainer Strainer Weights Size, M828 M822 in. [DN) 1 M804 M806 and M838 and M832 M824 D B Series M flanged strainers in iron and cast carbon steel. C 1/ /2 6 [15] (2.5) (2.5) (2.7) 3/ [20] (4.6) (5.5) (5.4) [25] (4.6) (5.9) (5.4) 1 1 / [40] (5.9) (10.9) (5.6) (8.1) (12.4) [50] (8.0) (11.8) (8.2) (10.0) (18) 2 1 / [65] (12.0) (18.2) (12.7) (14.5) (27.2) [80] (15.0) (26.8) (15.4) (22.2) (35) [100] (27.0) (42.2) (25) (41) (72.5) [125] (43.0) (66.2) (41.0) (54.4) (115.0) [150] (60.0) (88.0) (69.0) (79) (165.0) [200] (112.0) (143.0) (100) (136) (304.0) Note: 1. Metric pipe equivalents. 9

10 Figure 2: (MAP) Design Pressure/Temperature Ratings System Design Temperature, C System Design Pressure, psig (non-shock) Prolonged exposure not recommended above 800 F for carbon steel strainers 921, 921SW 600 psi CS Saturation curve M824, 600 lb., Fig., CS System Design Pressure, bar (non-shock) M832, M lb., Fig. CS 921, 921SW M , 250 psi CI M838, M lb., Fig. CS System Design Temperature, F Screen Equivalent Guide Perforations Approximate Equivalent Diameter Number of perf. Mesh Fraction (in.) in. [mm] per square inch [0.51] / [0.84] / [1.14] / [1.57] / [3.18] / [0.13] 20x120 Dutchweave 100 Notes: 1. Standard perforation on most 900 series strainers. 2. Approximate particle size retention. 10

11 Screens Two types of screens for a range of process conditions: Perforated stainless steel or Monel in a wide range of opening sizes with high open area ratios for low pressure drops. Fine mesh stainless steel Dutchweave screens also available. Both types provide greater mechanical strength than ordinary square mesh. Machined recesses in the body and cap assure the proper fit of the screen and its alignment in the body. Perforated screen - easy to clean, less susceptible to clogging. Dutchweave screen for applications requiring retention of small particles. Screen Selector Guide Series 900 Type of Service Screen Opening (in.) Air or gas Dutchweave (100 mesh) Oil, low viscosity 0.033" or 0.045" perf. Oil, medium or high viscosity 0.045" or 0.062" perf. Steam 0.020" or 0.033" perf. Water, gasoline or light fuel oil 0.020" or 0.033" perf. Screen Selector Guide Series M800 1 Type of Sizes, in. [DN] Coarse Medium Fine Service Straining (in.) Straining (in.) Straining (in.) Air or gas Gasoline 1/2-4 [15-100] 1/32 perf. 60 mesh 100 mesh up [125 - up] 3/64 perf. 1/32 perf. 60 mesh 1/2-4 [15-100] 3/64 perf. 1/32 perf perf. 5 - up [125 - up] perf. 3/64 perf. 1/32 perf. Oil - Low 1/2-4 [15-100] 3/64 perf. 1/32 perf perf. Viscosity 5 - up [125 - up] perf. 3/64 perf. 1/32 perf. Oil - Medium 1 /2-4 [15-100] perf. 3/64 perf. 1/32 perf. Viscosity 5 - up [125 - up] 1/8 perf..057 perf. 3/64 perf. Oil - High 1/2-4 [15-100] 1/8 perf..057 perf. 3/64 perf. Viscosity 5 - up [125 - up] 1/4 perf. 1/8 perf perf. Steam 1/2-4 [15-100] 3/64 perf. 1/32 perf perf. 5 - up [125 - up] perf. 3/64 perf. 1/32 perf. Water 1/2-4 [15-100] 3/64 perf. 1/32 perf perf. 5 - up [125 - up] perf. 3/64 perf. 1/32 perf. Notes: 1. Series M800 screens are not interchangeable with Series Mesh lined screens. 11

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