'HVLJQ &9;0& 0D\ 4<<< (UUDWD 6KHHW IRU 'HVLJQ &9;0& 6WHDP &RQGLWLRQLQJ 9DOYH ,QVWUXFWLRQ 0DQXDO/ )RUP 87:4/ -DQXDU\ 4<<<
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
;1 5HLQVWDOO WKH GHVXSHUKHDWHU XQLW LQ WKH YDOYH RXWOHW XVLQJ D QHZ PRXQWLQJ IODQJH JDVNHW +NH\ 7:,1 7KH GHVXSHUKHDWHU VKRXOG EH RULHQWHG VR WKDW WKH QR]]OH+V, SRLQW GRZQVWUHDP1 <1 5HLQVWDOO WKH QXWV/ ZDVKHUV/ DQG VWXGV +NH\V 8;/ 8</ DQG 8:, DQG WLJKWHQ DFFRUGLQJ WR QRUPDO SLSLQJ IODQJH WRUTXLQJ SURFHGXUHV1 431 5HLQVWDOO WKH ZDWHU IODQJH +NH\ ;, QXWV/ ZDVKHUV/ DQG VWXGV DQG WLJKWHQ DFFRUGLQJ WR QRUPDO SLSLQJ IODQJH WRUTXLQJ SURFHGXUHV1
3DUWV /LVW .H\
'HVFULSWLRQ
4 9 ; 4< 53 545556576374767778797:858687888:8;8<969798999;9<-
%RG\ %RQQHW :DWHU )ODQJH '6+ 0RXQW %UDQFK '6+ 0RXQWLQJ )ODQJH &RQWURO 6OHHYH 3OXJ 6WHP 6HDW 1R]]OH 6HDW *DVNHW 6OHHYH *DVNHW %RQQHW *DVNHW 3LVWRQ 5LQJ 3LVWRQ 5LQJ '6+ 0RXQWLQJ )ODQJH *DVNHW %RQQHW 6WXG :DVKHU 6WHP 3LQ %RQQHW 6WXG %RQQHW 6WXG 1XW '6+ 0RXQW 6WXG '6+ 0RXQW 6WXG 1XW '6+ 0RXQW 6WXG :DVKHU *ODQG 5LQJ 3DFNLQJ 6HW *ODQG )ROORZHU *ODQG )ODQJH *ODQG 6WXG 1XW *ODQG 6WXG
'HVLJQ &9;0&
)LJXUH 4$1 'HVLJQ &9;0&$ $VVHPEO\ ZLWKRXW 0DQLIROG &RROLQJ 6HFWLRQ
.)LVKHU &RQWUROV ,QWHUQDWLRQDO/ ,QF1 4<<<> $OO 5LJKWV 5HVHUYHG &2107(./ )LVKHU/ )LVKHU05RVHPRXQW/ DQG 0DQDJLQJ 7KH 3URFHVV %HWWHU DUH PDUNV RZQHG E\ )LVKHU &RQWUROV ,QWHUQDWLRQDO/ ,QF1 RU )LVKHU05RVHPRXQW 6\VWHPV/ ,QF1
7KH FRQWHQWV RI WKLV SXEOLFDWLRQ DUH SUHVHQWHG IRU LQIRUPDWLRQDO SXUSRVHV RQO\/ DQG ZKLOH HYHU\ HIIRUW KDV EHHQ PDGH WR HQVXUH WKHLU DFFXUDF\/ WKH\ DUH QRW WR EH FRQVWUXHG DV ZDUUDQWLHV RU JXDUDQWHHV/ H[SUHVV RU LPSOLHG/ UHJDUGLQJ WKH SURGXFWV RU VHUYLFHV GHVFULEHG KHUHLQ RU WKHLU XVH RU DSSOLFDELOLW\1 :H UHVHUYH WKH ULJKW WR PRGLI\ RU LPSURYH WKH GHVLJQV RU VSHFLILFDWLRQV RI VXFK SURGXFWV DW DQ\ WLPH ZLWKRXW QRWLFH1
)RU LQIRUPDWLRQ/ FRQWDFW )LVKHU &RQWUROV= 0DUVKDOOWRZQ/ ,RZD 8348; 86$ &HUQD\ 9;:33 )UDQFH 6DR 3DXOR 38757 %UD]LO 6LQJDSRUH 45;794 3ULQWHG LQ 8161$1
5
Instruction Manual Form 5471 January 1999
Design CVX-C
Design CVX-C Steam Conditioning Valve Contents Introduction
.............................. 1 Scope of Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Principle of Operation
................... 2
Valve and Instrumentation Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Piping Considerations . . . . . . . . . . . . . . . . . . . . . . . . 3 Location of Pressure Tap . . . . . . . . . . . . . . . . . . . . . . 3 Location of Temperature Sensor . . . . . . . . . . . . . . . 4 Control Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Installation
................................ 5
Maintenance
.............................. 7 Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Removal of Valve Bonnet and Trim . . . . . . . . . . . . . 7 Removal and Replacement of Nozzles . . . . . . . . . . 8 Valve Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Parts Ordering . . . . . . . . . . . . . . . . . . . . . . . . . . .
10
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10
Introduction
W7012 / IL
Figure 1. Design CVX-C Steam Conditioning Valve
Scope of Manual
Only personnel qualified through training or experience should install, operate, and maintain a Design CVX-C valve. If you have any questions about these instructions, contact your Fisher Controls sales office or sales representative before proceeding.
Description The Design CVX-C steam conditioning valve (see figure 1) provides a convenient and efficient way to reduce steam pressure and temperature within a single device. Typical installations include steam backpressure control, turbine bypass, boiler start-up service, auxiliary steam letdown for drying rolls, kettles, equipment drives, plant heating, and other loads requiring dependable and accurate control of steam pressure and temperature. D102620X012
This instruction manual includes installation, maintenance, and operation information for the CON-TEKR Design CVX-C control valve. Refer to separate instruction manuals for instructions covering the actuator and accessories.
Design CVX-C Table 1. Specifications (for Standard Designs)
End Connection Sizes Design CVX-C: R 1 through 24-inch steam inlet, R 2 through 48-inch steam outlet, and R 1 through 4-inch spraywater End Connection Types R ANSI Buttweld (all sizes) R ANSI Raised Faced Flanges (all sizes) R ANSI Socket Weld (1 through 3-inch)
Configurations R Angle Pattern (Standard) R ”Y” Pattern (Optional) R ”Z” Pattern (Optional)
ANSI Ratings R Class 150 through 4500
Bonnet Types Bolted: Class 150 through 4500 Shutoff Classifications per ANSI/FCI 70-2 R Class IV (standard) R Class V (optional)
Trim Characteristics R Linear (standard) R Equal Percentage R Special
Body/Bonnet R SA105 Carbon Steel R SA182 GR Fl l (1-1/4 CR- 1/2 MO) R SA182 GR F22 (2-1/4 CR- 1 MO)
Principle of Operation The positioning of the valve plug within the control sleeve controls the steam flow (see figure 2). The control sleeve has an array of orifices to provide the control characteristic specified. As the plug is lifted from the seat, steam is permitted to pass into the center of the control sleeve, and out through the seat orifice. A signal from the pressure control loop to the valve actuator moves the valve plug within the control sleeve which increases or decreases the amount of free flow area. Retracting the plug increases steam flow.
2
Special materials such as F91 or stainless steel possible upon request Control Plug Sizes 36 through 350: 410 SS with Alloy 6 Guiding and Seating Surfaces Sizes 385 through 510: SA182 GR F22 with Alloy 6 Guiding and Seating Surfaces Stem Stem Sizes 1/2 through 1-1/4 Inch Diameter: SA 479 Type XM-I9 Stem Sizes 2 Inch Diameter and Larger: SA638 Grade 660 Cl A Control Sleeve Sizes 36 through 68: SA182 Grade F22 Ion Nitrided Sizes 82 through 510: SA217 Grade WC9 Ion Nitrided Seat Sizes 36 through 68: SA479 Type 410 with Alloy 6 Seating Surface Sizes 82 through 510: A743 Grade CA15 with Alloy 6 Seating Surface Piston Rings Alloy 25 or Alloy 6 Gaskets Inconel/Graphite Packing Graphite/Grafoil Nozzles R SA479 Type 410 (A/F Variable Orifice Nozzles
and Drilled Hole Orifices) R Type 303 SS (Fixed Orifice Nozzles) The outlet section of the valve is comprised of a combination cooler section/silencer. As the steam exits the seat orifice, it enters one or more concentric diffuser sections designed to further decrease steam pressure in stages. Flow is directed radially and axially, through the multiple orifice diffuser(s) to the outlet pipe. The outlet section is fitted with a cooling nozzle(s) connected to a water manifold. This manifold provides cooling water flow to individual cooling nozzle(s) installed in the pipe wall of the outlet section. The result is the creation of a fine spray mist injected into the highly turbulent outlet steam flow.
Design CVX-C
W7014-1 / IL
Figure 2. Design CVX-C Cross Sectional View
Valve and Instrumentation Installation The Design CVX-C valve should be located in an easily accessible location with sufficient clearance for maintenance. Suggested minimum clearance for removal of the actuator and plug is shown on the dimensional drawings that are created specifically for each valve. Although the preferred position for easy maintenance is vertical, the Design CVX-C valve can be mounted in any position except with the stem pointing down. For additional information regarding installations, such as drains, please refer to bulletin 85.1:015 CON-TEKR Steam Conditioning Valves Installation Guidelines.
Downstream straight run piping is a function of the particular operating conditions and is specified on the customer specification sheet for each valve. Indiscriminate use of pipe reducers or expanders to match the valve outlet to field piping is not recommended. Mismatched valve outlet piping can result in increased system noise and vibration levels. If field piping requires the use of these devices, reducers on the valve inlet should have a maximum angle of 30 degrees while outlet expanders should be limited to a maximum of 20 degrees. These recommendations are made to keep noise and vibration levels to acceptable limits.
Location of Pressure Tap Piping Considerations Maintain a minimum distance of three (3) feet of straight pipe upstream of the valve inlet connection.
It is important that the pressure tap be located at a distance of not less than ten (10) feet from the outlet of the valve. The pressure sensor and transmitter should be mounted in accordance with the manufacturerâ&#x20AC;&#x2122;s instructions.
3
Design CVX-C
FISHER 667-EZ SPRAYWATER CONTROL VALVE
PC
FISHER CVX-100-CA-FSB
STEAM
SPRAYWATER
STEAMFLOW
TC
TE
B2539 / IL
Figure 3. Typical Design CVX-CA Installation
Location of Temperature Sensor
Control Strategies
The location of the temperature sensor is dictated by the operating conditions of the application and is shown on the customer specification sheet. The type of temperature sensor and thermowell selected can significantly affect the lag time and control parameters of the temperature control loop. Consult the manufacturer of the temperature sensor for details. Mounting of the temperature sensor and transmitter should be in accordance with the manufacturerâ&#x20AC;&#x2122;s instructions.
Pressure control is normally a closed loop feedback system. The process variable can be either the upstream or downstream pressure, depending on the application. The temperature control strategy can be either feedforward or feedback depending on external factors and application requirements. A typical closed loop feedback temperature control system (see figure 4.) is used when there is an accurate and consistent method for temperature measurement. By definition, the system is dependent on detecting a deviation in
4
Design CVX-C setpoint and feeding this information back to the control system to initiate final control element adjustment. See figure 4 for an example. A typical feedforward temperature control system (see figure 5) is one that responds to input variables and makes adjustments to the final control element to keep the desired setpoint constant. Feedforward temperature control needs to be used when it is not possible to get accurate temperature measurement using normal feedback control techniques, when control performance requires more responsiveness, or when the control variables are changing in a disproportionate manner. Such control is available via the use of an external logic controlling device, e.g. PLC or DCS, and incorporating a control algorithm to determine the appropriate system response to achieve the desired outlet temperature. See figure 5 for an example.
Installation WARNING Personal injury or equipment damage caused by sudden release of pressure may result if the Design CVX-C valve is installed where service conditions could exceed the limits of the pressure class noted on the nameplate. To avoid such injury or damage, provide a relief valve for over pressure protection as required by government or accepted industry codes and good engineering practices. 1. Before installation, all piping upstream of the valve must be blown clean so that no particles such as welding slag, dirt or other foreign matter, are left in the pipe. Use care to keep foreign matter out of the line openings while preparing the valve installation. 2. Verify that the valve is clean inside. If possible, before fitting in the line, connect the actuator to a temporary air supply and operate to verify positioning. Disconnect the instrument lines (if applicable.)
WARNING Do not lift the valve by its actuator yoke! Personal injury or damage to equipment could occur if the valve is improperly lifted into place. 3. Arrange a lifting sling around the main valve body to safely lift the valve to the pipe opening.
WARNING Do not expose the valve to undue stresses by installing it in bent pipes or flanges. Personal injury and equipment damage could result from flange sealing failure due to improper installation. 4. Flanged Connectionsâ&#x20AC;&#x201D;Grease the flange connection bolts with a high temperature thread lubricant. Install flange gaskets and connection bolts per accepted practices and tighten securely. 5. Welded Connectionsâ&#x20AC;&#x201D;Welding procedures should be in accordance with the applicable codes and the base materials. For preheat, welding electrodes, and postweld heat treatment, refer to the applicable codes and practices. Materials are specified on the customer specification sheet. If the valve inlet and outlet connections are to be welded with the valve assembled, the valve plug should be maintained off the valve seat during all associated operations. If the valve is to be welded by SMAW process, the valve should be disassembled for welding to ensure that any weld slag is removed from the valve. 6. Flush the cooling water line until all debris is removed from the line prior to connecting it to the Design CVX-C valve. Use only clean sources of cooling water to reduce the possibility of nozzle clogging. A 100 mesh strainer should be installed on the water line as close to the valve as possible. Review strainer manufacturerâ&#x20AC;&#x2122;s pressure drop curves to determine appropriate strainer body size. You may need to use a strainer that is larger than the water line size. 7. A straight run of pipe is required downstream of the Design CVX-C valve to ensure complete vaporization of cooling water. Consult the Design CVX-C customer specification sheet for the required distance of straight pipe. 8. Typically, a temperature sensor should be mounted a minimum distance of 30 feet (9.1 m) downstream of the Design CVX-C valve. This distance will vary depending on a number of factors including steam velocity and percentage of spraywater. Consult the customer specification sheet provided with the unit for this distance. If you have any questions, contact your local Fisher Controls sales office or sales representative. The steam line should not have any branch lines dividing the steam flow between the Design CVX-C valve and the temperature sensor. 9. A typical control loop is illustrated in figure 3. A pressure transmitter senses the pressure downstream (or upstream in backpressure control applications). The pressure controller sends a signal to the actuator positioner opening or closing the Design CVX-C valve as required to maintain pressure. A rising stem opens the Design CVX-C valve to allow additional steam flow. A temperature sensor (TE) measures changes in
5
Design CVX-C STEAM
PC
TC
PT
TT
SPRAYWATER
B2589 / IL
Figure 4. Typical Feedback Control Strategy
DCS
PC
ZT TT
PT
FC TT
STEAM TC = TEMPERATURE CONTROLLER PC = PRESSURE CONTROLLER PT = PRESSURE TRANSMITTER TT = TEMPERATURE TRANSMITTER ZT = POSITION TRANSMITTER FM = FLOW MEASUREMENT DCS = DISTRIBUTED CONTROL SYSTEM FC = FLOW CONTROLLER
SPRAYWATER FM
B2591 / IL
Figure 5. Typical Feedforward Control Strategy
temperature and transmits a signal to the temperature control device. The output signal from the controller is sent to the positioner on the cooling water (spraywater) control valve (SWCV).
6
The positionerâ&#x20AC;&#x2122;s output signal strokes the SWCV open, increasing water pressure on the nozzles. Increasing water pressure upstream of the nozzles increases water flow through the nozzles.
Design CVX-C CAUTION Pneumatic lines (where applicable) should be thoroughly blown clean with dry air before connection. Check electronic lines for correct connection. 10. If foreign debris has been introduced into the valve or upstream piping during installation, it must be removed prior to using the valve for the first time. A Blowout or Blow-through tool can be purchased to match the Design CVX-C valve and allow piping blowdown without removal of the valve from the line. 11. After cleanliness of the piping system has been assured, connect instrumentation and power supply to the Design CVX-C valve actuator and associated equipment. 12. Monitor the Design CVX-C valve as the system is brought on line. Some visible vapors may be seen as the lubricants are heated. If you see any steam leaks after startup, disassemble the valve and replace the gaskets. If the stuffing box leaks, tighten gland nuts (68). If leakage continues, replace the packing.
Drain the process media from both sides of the valve. R Vent the power actuator loading pressure and relieve any actuator spring precompression. R Use lock-out procedures to be sure that the above measures stay in effect while you work on the equipment. Shut off water and steam flow and vent all system pressure before breaking any pressure boundaries.
WARNING Residual system pressure may be released during the following steps if the system was improperly isolated or vented. Use extreme care to prevent personal injury while loosening any fasteners in the pressure boundary.
Removal of Valve Bonnet and Trim 1. Disconnect all field connections to the positioner and actuator and remove the actuator from the valve. Consult actuator manufacturerâ&#x20AC;&#x2122;s documentation for assistance in actuator removal.
Maintenance Servicing Due to the care Fisher Controls takes in meeting all manufacturing requirements (heat-treating, dimensional tolerances, etc.), use only replacement parts manufactured or furnished by Fisher Controls.
WARNING Avoid personal injury or property damage from sudden release of process pressure or bursting of parts. Before performing any maintenance operations: R Disconnect any operating lines providing air pressure, electric power, or a control signal to the actuator. Be sure the actuator cannot suddenly open or close the valve. R Use bypass valves or completely shut off the process to isolate the valve from process pressure. Relieve process pressure from both sides of the valve.
2. Loosen the gland stud nuts (key 68) and remove along with the gland follower (key 65). If possible, remove packing rings (key 64) from the stuffing box. 3. Loosen bonnet bolts/nuts (55) using an even pattern to avoid uneven expansion of the gaskets. Remove the entire bonnet assembly, pulling evenly in line with the valve stem (key 23) centerline. Uneven bonnet removal can result in galling or bending of the valve stem. If difficulty is encountered removing the bonnet, check the bonnet for alignment and straighten the bonnet before making further attempts to remove it from the valve body. Note The bonnet must be handled with care while being removed from the body. Damage to the bonnet can result in gasket leakage while the valve is in service. Protect the bonnet by placing it on clean cloth or wood while the valve is disassembled. 4. Dislodge any remaining packing rings (key 64) from the stuffing box. Remove the gland ring (key 63) from the bottom of the stuffing box. Inspect all parts; gland
7
Design CVX-C Table 2. Recommended Bonnet Bolt Torque STEM
BOLT SIZE
BODY SPRING
NUT PIN
PLUG
WATER INJECTION HOLES A7191 / IL
Figure 6. AF Nozzle Cross Section
ring (key 63), gland follower (key 65), valve stem (key 23), and gland studs/nuts (key 68/69) for signs of wear. Replace parts that are damaged or show excessive wear. 5. Inspect the bonnet guiding surfaces and gasket mating surfaces. Light damage on the guiding surface may be repaired with an emery cloth or other suitable material. Damage to the gasket mating surface may require bonnet replacement to avoid leakage. 6. Remove the seat (key 24), control sleeve (key 21), and plug assembly (key 22, 23, and 53) as a single unit by grasping the valve stem (key 23) and pulling the assembly from the body cavity. 7. Separate the control sleeve (key 21) from the seat (key 24) and remove the plug assembly (key 22, 23, and 53) from the control sleeve by pushing the plug assembly down through the lower end of the control sleeve. Reference figures 8 and 9 for guidance in performing this disassembly.
Inch
THREADS PER INCH
RECOMMENDED BOLT TORQUE(1) LbfRft
1/2
13
9/16
12
71 95
5/8
11
125
3/4
10
200
7/8
9
290
1
8
405
1-1/8
8
550
1-1/4
8
730
1-3/8
8
980
1-1/2
8
1290
1-5/8
8
1650
1-3/4
8
2070
1-7/8
8
2560
2
8
3130
2-1/4
8
4490
2-1/2
8
6200
3
8
10800
1. Torques for lubricated studs with heavy hex nuts.
Removal and Replacement of Nozzles 1. Loosen and remove the nozzle flange stud nuts (key 58). 2. Remove the nozzle flange stud washers (key 59) and nozzle body flange (key 20). 3. Remove the nozzle sleeve (key 37) with spray nozzle (key 30). 4. Remove the nozzle sleeve gasket (key 47) and nozzle flange gasket (key 48).
8. Inspect hardfaced guiding and seating surfaces of the plug assembly and seat, as well as (if applicable) the piston rings (key 45 and 46), for wear or damage and replace if necessary.
5. Cut the tack weld holding the spray nozzle (key 30) in the nozzle sleeve. Liberally apply a penetrant type thread lubricant and allow to soak prior to unscrewing the nozzle from the nozzle sleeve (key 37).
9. Polish the control sleeve guiding surface. If the guiding surface is damaged, replace the control sleeve.
6. Replace the spray nozzle and tack with ER410 or other suitable welding rod. Maintain low heat input to prevent distortion of the nozzle.
10. Clean the valve seat. Light damage to the seating surface may be factory repaired by remachining the 45 degree seating angle.
7. Reinstall using reverse order of the disassembly. Use a high temperature grease on the fitting parts to aid in future disassembly. Torque nozzle flange nuts as indicated in table 2.
11. Remove all used gaskets and foreign matter from the interior of the valve and from the inlet and outlet openings. If the valve is equipped with one or more diffusers, remove any foreign matter that may be in the diffusers or that may be plugging the radial ports. Inspect all valve body guiding and sealing surfaces for any signs of wear.
8
8. If the old nozzles are to be inspected and/or cleaned for reuse refer to figure 6 for guidance. All nozzle parts should slide easily and smoothly together. Discard any nozzles that appear marginally operational. Do not attempt to disassemble the AF style nozzles by removing the pin.
Design CVX-C Table 3. Recommended Packing Nut Torque STEM DIAMETER Inch
ANSI PRESSURE CLASS
MAXIMUM TORQUE
MINIMUM TORQUE
LbfRft
LbfRft
150 300 600 900 1500 2500 150 300 600 900 1500 2500 300 600 900 1500 2500
6 7 10 13 16 18 12 15 22 30 37 45 27 37 46 57 67
4 5 7 9 11 13 8 10 15 20 25 30 18 25 31 38 45
1-1/4
300 600 900 1500 2500
36 49 61 75 90
24 33 41 50 60
2
300 600 900 1500 2500
48 67 88 108 125
43 61 80 98 115
1/2
3/4
1
Valve Assembly 1. Cleaningâ&#x20AC;&#x201D;Make certain that all interior surfaces of the valve body and bonnet (including the stuffing box) are clean and free of dirt, including the inlet and outlet openings. All surfaces of the valve interior that receive mating parts should be given special attention when cleaning. All sliding, fit, and gasket sealing surfaces should be coated with Felpro C5A or other similar high temperature lubricant prior to reassembly. Refer to figure 7 for reference. 2. Install the spiral wound seat gasket (key 41). If valve is installed horizontally, the gasket can be held in place by sticking it to the valve body with a liberal coating of high temperature grease. This will ensure that the gasket is properly seated. 3. Before insertion of the plug assembly (key 22,23,53) with new piston rings (key 45, 46) in the control sleeve, all surfaces should be cleaned and generously lubricated with high temperature grease. Insert the plug into the control sleeve (key 21), taking care not to misalign the two. The piston rings will need to be slightly compressed to pass into the sleeve. Any binding between the plug and sleeve must be thoroughly investigated and corrected prior to proceeding. 4. Reattach the seat (key 24) to the control sleeve (key 21). Refer to figures 8 and 9 for guidance. Insert the control sleeve (key 21), plug assembly (key 22, 23, 53), and seat (key 24) as an assembly. Check to make
sure cage is located below the minimum cage depth mark on the inside of the body, near the top of valve. The parts should slide easily into the valve body until the seat rests on the seat gasket (key 41). If resistance to insertion is felt, remove the seat and control sleeve and determine the cause of the problem before attempting reinstallation. 5. Lubricate bonnet studs (key 54) and fully screw them into the valve body. 6. Install the sleeve gasket (key 43). 7. Attach bonnet gasket (key 44) in the bonnet gasket retaining groove with high temperature grease. 8. Lubricate the bonnet locating surfaces and carefully install the bonnet (key 6). Use care to avoid bending the stem. There will be a separation of about 1/8-inch between the bonnet and the valve body after the bonnet is fully inserted. Inspect the bonnet gasket to ensure it is properly located. 9. Install bonnet stud washers and nuts (key 52 and 55) and hand tighten. 10. Tighten the bonnet nuts (key 55) in a uniform, multistage cross pattern. Monitor the distance between the bonnet and body and keep it even to ensure that the bonnet is being torqued evenly. It is recommended that torquing be performed in a minimum of four torque levels until the final torque level is achieved. You may need to torque multiple times at each torque level to ensure that the bonnet is torqued evenly. Required torque can be found in table 2, Recommended Bonnet Bolt Torque. 11. After the bonnet has been torqued to the required level, check the plug movement to ensure that the plug still moves freely. 12. Recheck cleanliness of the stuffing box. Insert the gland ring (key 63) over the stem and into stuffing box. Measure the depth of stuffing box before and after ring insertion to be certain that it has traveled to the bottom of the stuffing box. Insert packing rings (key 64), after lubricating with high temperature grease, into the stuffing box and staggering the gaps on adjacent rings. The gland follower (key 65) can be used to ensure that each packing ring is pushed down before installing the next packing ring. 13. After all packing rings are installed, thoroughly lubricate the gland studs (key 69) and insert the gland follower (key 65) and the gland flange (key 66). Tighten the gland stud nuts (key 68) tight enough to block leakage but not so tight that stem travel is hindered. Consult table 3, Recommended Packing Nut Torque for recommended torque levels. Evenly tighten the nuts to the maximum level, then loosen and retighten to the minimum torque level. After operating, further tightening may be required to prevent leakage.
9
Design CVX-C Table 4. Troubleshooting Guide Problem
Possible Solution
Stem packing is leaking
Tighten stem packing nuts
Stem packing is leaking after tightening stem packing nuts
Repack and replace worn parts as needed
Actuator cannot open valve
Check actuator calibration Check for overtightening of the packing nuts Check for alignment between actuator and valve
Actuator action is “sticky” sticky
Check positioner calibration Replace plug, cage, stem guide and/or packing follower Check water source availability and pressure
Temperature setpoint is not reached
Check nozzle for plugging Make sure that steam saturation pressure is not above setpoint Check to ensure full spraywater control valve actuator stroke is reached Check temperature control loop – reset
Temperature Tem erature is below setpoint set oint
Check nozzle for fouling/poor spray pattern – clean/replace Check temperature sensor location – relocate per guidelines
Temperature oscillates around setpoint Water in steam line Water in steam line when steam line isolated Noise and vibration seem high Bonnet gasket is leaking
14. Install the actuator on the valve in accordance with the manufacturers standard procedure. After calibration of the actuator, the valve should be ready to return to service.
Troubleshooting Table 4 is intended as a basic first line troubleshooting guide. Contact your Fisher Controls sales office or sales representative for assistance if you are unable to resolve your field operation problem.
Parts Ordering Each Design CVX-C valve is assigned a serial number that can be found on the bonnet flange. Refer to the serial number when contacting your Fisher Controls representative for technical assistance. When ordering replacement parts, refer to the serial number and key numbers for each part required. The key numbers in the Parts List and the assembly drawing in figure 7 can be used to help in part identification.
10
Tune control system parameters Temperature setpoint may be too close to saturation Check that steam traps are functioning properly Review piping configuration for downstream tees and elbows Check for leakage of spraywater control valve Review piping configuration and insulation Inspect valve diffuser Inspect body/bonnet mating surfaces, replace bonnet gasket. Ensure bonnet bolts are properly torqued
Parts List Key
Description
01
Body SA 105SA 182 Grade F11 SA 182 Grade F22 06 Bonnet SA 105 SA 182 Grade F11 SA 182 Grade F22 20 Nozzle Body Flange SA 105 SA 182 Grade F11 SA 182 Grade F22 21* Control Sleeve SA 182 Grade F22 Ion Nitrided (SOD Sizes 36-68) SA 217 Grade WC9 Ion Nitrided (SOD Sizes 82-510) 22* Plug SA 479 Type 410/Alloy 6 (SOD Sizes 36-350) SA 182 GRF22/Alloy 6 (SOD Sizes 385-510) 23* Stem SA 479 Type XM-19, less than 2” diameter SA 638 Grade 660 Cl A, 2” diameter and larger 24* Seat SA 479 Type 410/Alloy 6 (SOD Sizes 36-68) SA 743 Grade CA 15/Alloy 6 (SOD Sizes 82-510) 30* Spray Nozzle, SA 479 Type 410 37 Nozzle Sleeve, SA 182 Grade F22 41* Seat Gasket, Inconel 600/Graphite 43* Sleeve Gasket, Inconel 600/Graphite 44* Bonnet Gasket, Inconel 600/Graphite 45/46* Piston Rings, Alloy 25 or Alloy 6 47* Nozzle Sleeve Gasket, Inconel 600/Graphite 48* Nozzle Flange Gasket, Inconel 600/Graphite 52 Bonnet Stud Washer, Plated Steel 53* Stem Pin, 316 SST
*Recommended spare parts
Design CVX-C 23 66
69
65
68
63
64
6 53
54
44
55
43
52
48 45 22 21 1 24 41
58 57
20
59 37
48
30
47 B2642 / IL
Figure 7. Design CVX-CA Assembly
Key
Description
Key
Description
54
Bonnet Stud SA 193 Grade B7, SA105 Valves SA 193 Grade B16, SA182 GR F11 and F22 Valves Bonnet Stud Nut SA 194 Grade 2H, SA105 Valves SA 194 Grade 7, SA182 GR F11 and F22 Valves Nozzle Flange Stud SA 193 Grade B7, SA105 Valves SA 193 Grade B16, SA182 GR F11 and F22 Valves Nozzle Flange Stud Nut SA 194 Grade 2H, SA105 Valves SA 194 Grade 7, SA182 GR F11 and F22 Valves Nozzle Flange Washer Plated Steel
63*
Gland Ring SA 479 Type 316 Packing Set Graphite/Grafoil Gland Follower SA 479 Type 316 Gland Flange SA 479 Type 316 Gland Stud Nut SA 194 Grade 2H Gland Stud SA 194 Grade B7
55
57
58
59
*Recommended spare parts
64* 65* 66* 68* 69*
11
Design CVX-C
INTERNAL THREADS
2
NOTES: 1. UNSCREW SEAT FROM CAGE. 2. REMOVE PLUG FROM LOWER END OF CAGE.
EXTERNAL THREADS
B2640 / IL
1
Figure 8. Design CVX-C Trim Assembly (Sizes 160 and Smaller)
INTEGRAL CAGE PIN (TWO, 180_ APART)
2
NOTES: 1. ROTATE SEAT UNTIL CAGE PIN ALIGNS WITH SEAT SLOT. SEPARATE SEAT FROM CAGE. 2. REMOVE PLUG FROM LOWER END OF CAGE.
PIN SLOT (TWO, 180_ APART)
B2641 / IL
1
Figure 9. Design CVX-C Trim Assembly (Sizes 175 and Larger)
CON-TEK, Fisher, Fisher-Rosemount, and Managing The Process Better are marks owned by Fisher Controls International, Inc. or Fisher-Rosemount Systems, Inc. All other marks are the property of their respective owners. EFisher Controls International, Inc. 1999; All Rights Reserved
For information, contact Fisher Controls: Marshalltown, Iowa 50158 USA Cernay 68700 France Sao Paulo 05424 Brazil Singapore 128461 12 Printed in U.S.A.