® UTILITY IRON BODY CONTROL VALVES Form TI 596SI v2 TECHNICAL INSTRUCTIONS Iron Body Series 596 SI UTILITY IRON BODY SERIES DESCRIPTION The rugged Powers Type SI (single seat iron body) valve is primarily used for steam and water modulating applications with moderate pressure drops. The equal percent plug provides excellent control characteristics and is more tolerant of oversizing than linear or quick-opening plugs. The SI’s control and close off characteristics are particularly well-suited to commercial water heaters, boilers, and industrial utility applications. The SI valve is available with the Powers 46 in.2. and 100 in.2. actuators. Actuator selection depends on valve size and flowing system pressure drop across the valve. SPECIFICATIONS VALVE Body Sizes: Body Material: End Connections: Trim: Packing: Seat Leakage: Cv Range: Rangeability: Characteristics: Maximum Pressure: Max. Differential Press.: Temperature Range: ACTUATOR Housing Construction: Diaphragm Construction: Diaphragm Area: Maximum Pressure and Temp.: Ambient Shipping Limits: Ambient Operating Limits: Air Connection: Position Indication: Mounting: 2 1/2" – 6" Cast Iron (per ASTM A126-93 Class B) 125 # Flanged (per ANSI B16.1–1993) Bronze Composition Disc or Stainless Steel Teflon disc Spring loaded TFE packing ANSI Class IV < 0.01% leakage 56-350 75:1 Equal Percent 200 psi @ Temp. <150°F 50 psi for Bronze, 100 psi for Stainless Steel 40° – 281° F Normally-closed 596SI with 46 in. 2 actuator shown Sizes 2 1/2” 3” 4” 5” 6” Actuators Available 46 in.2 or 100 in.2 Diaphragm 46 in.2 or 100in.2 Diaphragm 46 in.2 or 100 in.2 Diaphragm 100 in.2 Diaphragm 100 in.2 Diaphragm TABLE OF CONTENTS Die cast aluminum Replaceable molded neoprene 46 in.2, 100 in.2 35 psi and 200°F - 40 to 220° F - 20 to 220° F 46 in.2 1/4” NPT 100 in.2 1/8” NPT 1/8” increments In any upright position with actuator head above 45° of the center line of the valve body. Actuator head may be swiveled to any convenient position. Description............................................................................ 1 Specifications............................................................................... 1 Application Information ............................................................... 2 Theory of Operation..................................................................... 2 Valve Sizing and Selection ............................................................. 3-4 Close Off Data .......................................................................... 5 Temperature/Pressure Ratings .................................................... 5 Dimensional Data ........................................................................... 6 Installation .................................................................................... 7 Maintenance ................................................................................. 7 Ordering Information....................................................................... 8 CALIFORNIA PROPOSITION 65 WARNING WARNING: This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. (California law requires this warning to be given to customers in the State of California.) For more information: www.wattsind.com/prop65 Page 2 Form TI 596SI v2 APPLICATION INFORMATION Flowrite II Single Seated SI Valves are generally recommended for steam, hot water and chilled water applications. They are particularly suited for installations requiring tight shutoff and quick response. THEORY OF OPERATION On normally closed valve assemblies, the valve stem will start to open whenever the control air pressure applied against the actuator diaphragm area and the lower housing exceeds the holding force of the springs. A further increase in control air pressure will initiate a continued upward travel of the valve steam until the valve has fully opened. Figure 1 B- Push to Close Figure 1 A- Push to Open When the valve is at its’ "full open" position there is maximum flow potential through the valve. At this position, valves are compared based on flow that is directly related to the valve flow coefficient (see Cv equations in table 1). The 596 SI valves are designed so that equal changes in valve stem position provide equal percentage changes in existing flow through the valve. This is otherwise know as an equal percent valve which has a typical flow curve (figure 2) that can be used to determine flow based on stem position, pressure drop, and Cv. As you can see from the graph, these valves are less sensitive at the low end, which gives both high rangeability and high flows. These types of valves are used extensively to compensate for fluctuating system requirements (pressure, flow, load, etc.). Valve actuators equipped with positioners provide feedback for enhanced control strategies and, as an example, are required for valve staging. Valves with positioners can utilize full control air pressure at any point in stem travel to initiate stem movement or to maintain stem position. However, the actuator springs still provide the necessary force to move the stem in the opposite direction. Use of a positioner will tend to provide faster response and ensure repeatability of stem position regardless of the load on the actuator. However, in a system where available pressure and flow requirements are relatively consistent, control valves can usually perform adequately without a positioner. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% The air pressure change to initiate full stem travel is known as the spring range or span. This spring span is factory set and will vary slightly as the pressure drop across the valve changes. 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Percent Flow On normally open valve assemblies, the stem will start to close whenever the control air pressure applied against the actuator diaphragm area and upper housing exceeds the holding force of the springs. A further increase in control air pressure will initiate a continued downward travel of the valve stem until the valve has fully closed. Fully Closed Percent Travel Figure 2 Fully Open Form TI 596SI v2 Page 3 VALVE SIZING AND SELECTION (WATER) The sizing of a valve is very important if it is to render good service. If it is "undersized", it will not have sufficient capacity. If it is "oversized", the controlled variable may cycle, the trim can be exposed to excessive wear or wire drawing, and you could expect reduced valve life. To help select the right valve, it is important to understand your application and its variables (controlled fluid, temperatures, pressures, min/max load, etc.). When your system variables are known and you have calculated actual demand, it is possible to select the right Powers valve for your application. The following technical data should help you in selecting a valve for your water control applications. For fluid applications other than water, contact Powers’ application engineering. On/Off Control: These types of applications are normally line sized to reduce pressure drop and pump size. In these applications it is important to verify valve seat leakage will not result in system overheat or damage. If this is a concern, it is necessary to take precautions to alleviate this potential problem. Proportional Control: In applications where the close-off pressure at the valve is below 20psig, use a pressure drop of 5psi. In applications where the close-off pressure at the valve is above 20psig, it is generally recommended to take 25-50% of the system pressure drop at the control valve to maintain good valve/system performance. Certain applications can successfully utilize lower pressure drops across the valve (5-25%) if system fluctuations are kept to a minimum. If not, the valve is considered oversized it will not effectively throttle until it is nearly closed thereby resulting in poor control. Refer to the following table for flow…. Table - 1 Water Capacity in Gallons Per Minute Valve Size 2.5 3 4 5 6 Cv Rating 65 85 145 235 350 5 145 190 324 525 783 10 206 269 459 743 1107 20 291 380 648 1051 1565 Differential Pressure (∆P in psi) 30 40 50 60 356 411 460 503 466 538 601 658 794 917 1025 1123 1287 1486 1662 1820 1917 2214 2475 2711 70 544 711 1213 1966 2928 80 581 760 1297 2102 3130 90 617 806 1376 2229 3320 100 650 850 1450 2350 3500 125 727 950 1621 2627 3913 CAVITATION LIMITATIONS ON VALVE PRESSURE DROP A concern in high temperature water systems is the potential for cavitation/flashing, which is caused by the downstream pressure being lower than that of the vapor pressure of the fluid. This basically causes the water to "boil" and can result in reduced flow/capacity, excessive noise, vibration, wear and should be avoided if possible. Use the following equation to estimate the maximum allowable pressure drop across the valve: Table-2 Vapor Pressure of Water Table Pmax = 0.5 (P1 – Pv) Where: Pmax = Maximum allowable pressure drop P1 = Absolute inlet pressure (psia) Pv = Absolute vapor pressure (refer to psia - Table 2) Absolute pressure = gage pressure + 14.7 Water Temp. (°F) Vapor Pressure (psia) Water Temp. (°F) Vapor Pressure (psia) 40 50 60 0.12 0.18 0.26 140 150 160 2.89 3.72 4.74 70 80 90 0.36 0.51 0.70 170 180 190 5.99 7.51 9.34 100 110 120 0.95 1.28 1.69 200 210 220 11.53 14.12 17.19 130 2.22 230 20.78 Page 4 Form TI 596SI v2 VALVE SIZING AND SELECTION (STEAM) Steam: One can use the same reasoning for selecting a valve in steam applications as would be used for water applications. Once again, pressure drop selection is a major determining factor for good control and system performance. In general, for steam applications, the largest possible pressure drop should be taken without exceeding the critical pressure ratio. Proportional Control: For pressures less than 15 psig, use an 80% of the gauge inlet pressure as a differential. For pressures above 15psig, use 50% of the absolute inlet pressure. In those cases where the required Cv falls between two valves, select the larger size. One may be concerned about steam entering a heating coil at 0 psig when these large pressure drops are taken at the valve. However, flow will continue as the pressure in the coil will drop to vacuum pressures due to the steam condensation. It is essential to use proper condensate piping and steam trapping in these applications. On/Off Control: These types of applications are normally line sized to reduce pressure drop. In these applications it is important to verify valve seat leakage will not result in system overheat or damage. If this is a concern, it is necessary to take precautions to alleviate this potential problem. Table - 3 Steam Capacity in Pounds Per Hour Steam Inlet Pressure (psig) Pressure Drop Across Valve (psi) Valve Cv Size Rating 2 0.5 5 1 2 10 1 2 3 4 5 2 4 6 8 10 2.5 65 554 777 1082 846 1181 1426 1624 1790 1329 1839 2203 2484 2709 3 85 724 1016 1415 1106 1544 1865 2124 2341 1738 2405 2880 3249 3543 4 145 1235 1733 2413 1887 2634 3182 3623 3993 2965 4103 4914 5542 6044 5 235 2002 2809 3911 3058 4268 5157 5872 6472 4805 6650 7964 8981 9796 6 350 2981 4184 5825 4555 6357 7681 8746 9639 7156 9905 11861 13376 14589 Steam Inlet Pressure (psig) Pressure Drop Across Valve (psi) Valve Cv Size Rating 15 25 50 (max) (max) (max) 3 6 9 12 15 5 10 15 20 10 20 30 2.5 65 1776 2443 2907 3255 3523 2633 3596 4242 4705 4717 6385 3 85 2322 3195 3802 4257 4607 3443 4702 5548 6152 6168 8350 9747 10017 4 145 3961 5450 6485 7262 7858 5873 8022 9464 10495 10522 14243 16628 17088 5 235 6419 8834 10511 11770 12736 9518 13001 15338 17010 17053 23084 26949 27694 6 350 9561 13156 15654 17529 18968 14176 19363 22844 25334 25397 34380 40137 41247 Steam Inlet Pressure (psig) Pressure Drop Across Valve (psi) Valve Cv Size Rating 75 100 25 (max) 35 45 10 7660 125 (max) 10 7454 32.5 25 36 58 (max) 20 50 70 2.5 65 5618 8481 9704 10615 6394 9758 11390 13610 9832 14619 16526 3 85 7347 11090 12690 13882 8361 12760 14894 17797 12857 19117 21611 4 145 12533 18918 21647 23681 14263 21767 25408 30360 21932 32611 36866 5 235 20312 30661 35084 38379 23116 35277 41178 49205 35546 52853 59748 6 350 30251 45665 52252 57160 34428 52541 61329 73284 52940 78717 88987 Steam Inlet Pressure (psig) Pressure Drop Across Valve (psi) Valve Cv Size Rating 150 175 (max) 200 (max) (max) 25 50 83 50 70 95 50 75 108 2.5 65 11908 16134 19521 17518 20088 22437 18800 22254 25431 3 85 15572 21098 25527 22908 26269 29340 24585 29102 33256 4 145 26563 35990 43546 39078 44812 50051 41939 49644 56731 5 235 43051 58329 70574 63334 72627 81117 67971 80457 91944 6 350 64118 86873 105111 94327 108167 120813 101233 119830 136937 Form TI 596SI v2 Page 5 CLOSE OFF DATA In all cases requiring greater close off, a preload adjustment is possible. Consult with factory for your application. Close Off Ratings for Normally Closed Valves Close Off ( ∆ P in psi) Signal-to-Actuator Valve Size Actuator (in) 5 (in2) 46 100 (1U) 46 100 (1U) 46 100 (1U) 100 (1U) 3-15 PSI 26 96 15 63 6 32 19 1-17 PSI 53 125 34 92 16 48 29 0-30 PSI 106 125 70 92 36 48 29 6 100 (1U) 12 19 19 2.5 3 4 (Positioner) Close Off Ratings for Normally Open Valves Close Off ( ∆ P in psi) Signal-to-Actuator Valve Size (in) 2.5 3 4 5 6 Actuator (in2) 46 100 (1L) 46 100 (1L) 46 100 (1L) 100 (1L) 100 (1L) 3-15 PSI 49 125 32 90 15 48 29 19 (Positioner) 0-30 PSI 125 125 125 125 77 125 105 72 1-17 PSI 86 125 58 118 30 64 39 26 169 psig TEMPERATURE/PRESSURE RATINGS Maximum Media Temperature 281¡F 300 Temperature — ¡F In all cases, do not exceed the temperature/pressure ratings of the valve (see figure 3). Acceptable region is shown by the shaded area. 250 200 150 596SI 100 Minimum Media Temperature 40¡F 50 50 150 100 200 Pressure — psig Figure 3 - Temperature and Pressure Ratings Page 6 Form TI 596SI v2 DIMENSIONAL DATA Table-4 Dimensions for 596 SI Series Valves Nominal Pipe Size 3” 4” 5” A STROKE 8.500 0.938 2-1/2” 9.500 0.938 11.500 0.938 13.000 1.938 14.000 1.938 6” B1 B2 C1 C2 D E F G Valve Weight (lbs) Weight w/46” Weight w/100” 4.125 3.500 4.125 3.875 10.375 10.000 16.625 10.313 52.00 65.00 77.00 4.125 3.750 4.375 4.250 10.375 10.000 16.625 10.313 65.00 78.00 90.00 5.063 4.500 5.000 4.875 10.375 10.000 16.625 10.313 90.00 103.00 115.00 6.750 5.000 5.500 5.500 N/A N/A 19.000 10.313 150.00 N/A 180.00 7.375 5.500 6.500 6.375 N/A N/A 19.000 10.313 225.00 N/A 255.00 Figure 4 - 2-1/2” to 6” Valve Bodies G E 100" Actuator F 46" Actuator D C2 Normally Open Valve C1 Normally Closed Valve B1 B2 A Table - 5 Flange Detail for American Standard 125 lb. Cast Iron Pipe Flanges Valve Size Flanges Flange Diameter Flange Thickness Drilling Diameter of Bolt Circle A B C D 2-1/2" 3" 4" 5" 6" 7" 7-1/2" 9" 10" 11" 11/16" 3/4" 15/16" 15/16" 1" 5-1/2" 6" 7-1/2" 8-1/2" 9-1/2" 3/4" 3/4" 3/4" 7/8" 7/8" Diameter of Bolt Holes Bolting Number of Bolts Diameter of Bolts E 4 4 8 8 8 5/8" 5/8" 5/8" 3/4" 3/4" E Figure 5 D B C A Length of Machine Bolts 2-1/2" 2-1/2" 3" 3" 3-1/4" Form TI 596SI v2 Page 7 INSTALLATION Inspection Inspect the package for damage. If damaged, notify the appropriate carrier immediately. If undamaged, open the package and inspect the device for obvious damage. Return damaged products. Requirements • Pipe wrenches • Flange gaskets, bolts/nuts • Installer must be a qualified, experienced technician CAUTION! • Install the valve with the flow in the direction of the flow arrow. • Do not exceed the ratings of the device. • Avoid locations where excessive moisture, corrosive fumes, or vibration are present. Mounting/Orientation 1. The valve should be mounted in a location that is within the ambient limits of the actuator. When selecting a location, allow sufficient room for valve linkage, actuator, and other accessories and for service of the product. 2. The preferred mounting position for the valve is with the valve stem vertical above the valve body. Avoid mounting the valve so that the valve stem is below horizontal. 3. On steam applications where the ambient temperature approaches the limit of the actuator, the valve stem should be mounted 45° from vertical. Figure 6 - Installation of Flanged End Valves Valve Body Gasket: Supplied by Others Companion Flange Flanged Connection The 596SI series flanged valve bodies conform to American Standard 125 Lb. Cast Iron Pipe Flanges. The companion flanges (not provided) should be the same specification as the valve. The 125 lb. flanges have plain flat faces and should not be bolted to a raised faced flange. 1. 2. 3. 4. All parts should be clean to assure the best results. The pipe with the companion flanges installed should be properly supported and aligned. Be sure the companion flange is flush with the face of the valve body flange and lined up squarely. Use a gasket material (not provided) that is recommended for the medium being handled. CAUTION! Do not apply pipe dope to the valve flange, gasket, or companion flange. See Figure-5 for flange and flange bolt details. Figure-6 shows the proper way a flanged valve should be mounted. MAINTENANCE Regular maintenance of the total system is recommended to assure sustained performance. See Table-6 for maintenance kit part numbers. Table - 6 Maintenance Kits for 596SI Valves Valve Description Replacement Packing Assembly 2.5 Normally Closed 596 Pack 3 Normally Closed 4 Normally Closed 5 Normally Closed 6 Normally Closed 2.5 Normally Open 3 Normally Open 4 Normally Open 5 Normally Open 6 Normally Open * Kit includes replacement packing and stem & plug assembly. Water System Maintenance All systems are susceptible to valve and system problems caused by improper water treatment and system storage procedures. These guidelines are provided to help avoid valve and water system problems resulting from improperly treated water or storage procedures and to obtain maximum life from the valves. Durability of valve stems and packings is dependent on maintaining nondamaging water conditions. Inadequate water treatment or filtration can result in corrosion, scale, and abrasive particle formation. Scale and Replacement Gaskets Valve Repair Kit* 596250G 596300G 596400G 596500G 596600G 596250G 596300G 596400G 596500G 596600G SIGOBCTK SIHOBCTK SIJOBCTK SIKOBCTK SILOBCTK SIGOBXTK SIHOBXTK SIJOBXTK SIKOBXTK SILOBXTK particulates can result in stem and packing scratches and can adversely affect packing life and other parts of the hydronic system. To maintain non-damaging conditions, follow these guidelines: • Clean the system prior to start up. • Use filtration equipment where needed. • Properly store off-line systems and monitor water treatment results. • Follow the advice of a water treatment professional. Page 8 Form TI 596SI v2 ORDERING INFORMATION 596– S Size 2 1⁄2″ 3″ 4″ 5″ 6″ I Order Code 250 300 400 500 600 End Connections 125# Flange F Valve Trim Bronze Stainless Steel B S Action Fail Open (Air-to-Close) Fail Closed (Air-to-Open) X C Packing Teflon T ACCESSORIES SELECT CODE (see below) ACTUATOR SELECT CODE (see below) ACTUATOR SELECT CODE CODE PNEUMATIC DIAPHRAGM ACTUATORS 46 46 Sq. In., 1” Max Valve Stroke with Stainless Steel Springs, adjustable start w/ 7 ~ 12 lb. Fixed span. 4X 46 Sq. In., 1” Max Valve Stroke with Extended Springs (requires positioner), adjustable start w/22 lb. span. 1U 100 Sq. In; 8-13 psi Spring Range, (Normally Closed Valves) 1L 100 Sq. In; 3-8 psi Spring Range, (Normally Open Valves) ACCESSORIES SELECT CODE CODE IS TS US DESCRIPTION Bellofram 1000 I/P’S 3–15 psi 1–17 psi 3–27 psi ES CONTROL/AIR TYPE 900X I/P 0–30 psi BS UTILITY POSITIONER AND I/P 4–20 mA PS RS SS UTILITY POSITIONER 3-15 psi 3-9 psi 9-15 ps OS NO ACCESSORIES No Accessories I/P TRANSDUCERS The “standard” 3-15 psi signal was originally designed as a transmission signal, not a valve actuation signal. The Fluid Controls Institute (in Standard 87-2) has recommended that a 1–17 psi air signal range be used when directly actuating a control valve without a positioner. Powers concurs with this recommendation, and therefore, offers a 1–17 psi I/P transducer and a 0–30 psi I/P transducer and the Accritem pneumatic controller for maximum close-off. 3-15 psi I/P transducers should be used in conjunction with positioners. POSITIONERS Positioners are used for one or more of the following reasons: 1) To split range valves. 2) To eliminate unwanted valve movement caused by line pressure variations 3) To minimize the effects of “stick-slip” 4) To speed response time and/or 5) To increase close-off rating when I/Ps are used. © 2004 Powers, a division of Watts Water Technologies, Inc. USA Phone: 1.800.669.5430 • Fax 1.847.824.0627 Canada Phone: 1.888.208.8927 • Fax 1.888.882.1979 www.powerscontrols.com Form TI 596SI v2 0403 EDP# 6512248 Printed in U.S.A.
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