490 Series Actuators. 490 Series. Contents. Introduction

Transcription

1 Instruction Manual Form 049 May Series 490 Series Actuators Contents Introduction Scope of Manual Description Specifications With Positioner Without Positioner Type Type Making Up Stem Connection Principle of Operation 2 Handwheel Operation 3 Installation 3 Maintenance 4 Parts Ordering Parts List Introduction Scope of Manual This instruction manual pertains only to the actuator combinations described below. The operation and maintenance of the Type 370P and 370PC positioners are covered in Instruction Manual, 370 Series Pneumatic Valve Positioners. Only personnel qualified through training or experience should install, operate, and maintain 490 Series actuators. If you have any questions about these instructions, contact your Fisher Controls sales office or sales representative before proceeding. Description Type 490 Pneumatically operated, long-stroke piston actuator with positioner bracket-mounted beside the cylinder. Stem position feedback is through a spool and cable arrangement. The Type 370P has pressure gauges showing input pressure and top and bottom cylinder pressures. The Type 370PC has tire valves instead of pressure gauges and the nozzles are W209/IL Figure 1. Type 49 Actuator locked in place to resist vibration. The available yoke boss sizes for valve mounting are -inch diameter for extra heavy bolting (designated H) and 7-inch diameter. Type 491 Same as the Type 490 but without the positioner assembly. Suitable for on-off service where the cylinder is loaded and unloaded through the operation of a solenoid valve, pneumatic switching valve or similar equipment. D0X0

2 Table 1. Specifications Cylinder Pressure Minimum Recommended: For valves with low thrust requirements 3 psig (2.4 bar); for all other valves 0 psig (3.4 bar) Maximum Allowable: -inch (7 mm) to -inch (30 mm) Diameter Cylinders 20 psig (17.2 bar) unless limited by maximum allowable supply pressure of positioner or switching devices; -inch (3 mm) diameter cylinder 200 psig (13. bar) unless limited by maximum allowable supply pressure of positioner or switching device Maximum Supply Source Consumption (1) With Positioner and Constant Input Signal: 20 scfh (0.4 normal m 3 /hr) of air at 0 psig (.9 bar) Types Without Positioner: Depends on cylinder volume and supply pressure Travel Information All Types: 9 inches (229 mm) through 24 inches ( mm) in 1-inch (2 mm) increments Travel Ratio for Type 49 (Handwheel Version): complete revolutions of wheel moves stem 1 inch (2 mm). Wheel rim force is 3 lb (23 N), which produces a handwheel output force of 490 Lbf in (99 N m) 1. Scfh Standard cubic feet per hour (0 F and.7 psia); normal m 3 /hr normal cubic meters per hour (0 C and bar, absolute). 2. These terms are defined in ISA Standard S Operative Ambient Temperature (2) 20 F to F ( 29 C to 2 C) Yoke and Valve Stem Diameters H (3) (7 mm) Yoke Boss Diameter: 1- or 1-1/4 inch (2.4 or 31. mm) stem diameter 7-inch (17 mm) Yoke Boss Diameter: 2-inch (0. mm) stem diameter Pressure Connections Standard is 1/4-inch NPT. For larger sizes, consult your Fisher Controls sales office or sales representative Options Steel cylinder for -inch (24 mm) and -inch (30 mm) diameters High temperature piston seals to 30 F (177 C) Brass cylinder for -inch (3 mm) diameter 377 Series trip valves to fail actuator up, down, or lock in last position Type 304 electrical valve stem position switch Micro-Switch (4) limit switches 1- through 24-inch cylinder sizes 3. Heavy actuator to bonnet bolting. 4. Trademark of Micro-Switch Company. Type 49 Same as the Type 490 but with an integral, 17-inch diameter, side-mounted handwheel. Ten revolutions of the handwheel move the stem one inch. The handwheel assembly can be used to open, close, or position the valve; or it may be used as a stop to limit upward travel of the valve plug. Type 491- Same as the Type 491 but with the handwheel, as described for the Type 49. Specifications Specifications for the 490 Series actuators are shown in table 1. Principle of Operation With Positioner Refer to figure 2. The pneumatic output signal from a controller or instrument is piped to the bellows of the Type 370P positioner. For explanation purposes, assume this input signal has increased. The bellows expands and moves the beam which pivots around a fixed point and simultaneously uncovers the nozzle of relay B and covers the nozzle of relay A. The nozzle pressure in relay A increases due to the restriction created by the beam over the nozzle. Through relay action, the air pressure to the top of the piston increases. At the same time, relay B reacts to the change in beam position to decrease the pressure to the underside of the piston. Due to the unbalanced pressures acting on the piston, it moves down. Piston movement is fed back to the beam by means of a range spring connected to the actuator-valve stem connector by a cable. This feedback arrangement prevents over-correction and ensures a definite position of the piston for a given input signal, thus giving stable and accurate response to a change in controlled conditions. Upon receipt of a decreasing input signal, the reverse action takes place. The bellows contracts and, as the beam pivots, it restricts the nozzle of relay B and uncovers the nozzle of relay A. Through relay action, the pressure below the piston increases and the pres- 2

3 Handwheel Operation 490 Series With the pointer (key 42, figure 4) in the neutral position, automatic operation is possible throughout full travel. The locking pin (key ) should be left out during automatic operation, and the needle valve (key 4, figure 4) must be closed. For manual operation, the locking pin must be inserted into the hole in the sleeve assembly before you open the needle valve. Rotation of the handwheel in either direction causes the valve stem to move because of the pinned connection between the piston rod extension and sleeve. There is a directional arrow and the word OPEN cast on the handwheel to indicate the rotation required to open the valve. To shift from manual to automatic operation, return the handwheel pointer to the neutral position, close the needle valve, and knock out the tapered pin. The unit can provide a travel stop to restrict upward travel of the valve plug. When you set the travel stop, the tapered pin should be left out. As an example, consider the control valve with a push-down-to-close valve plug action. To restrict full opening, turn the handwheel to lower the sleeve assembly (key 9). In normal operation, as the valve opens, the stem connector (key 22) contacts the lower part of the sleeve before full valve travel is reached. You can note the amount of restriction on the travel scale (key 7). 22A70-A A71/IL If an emergency arises, you can close the valve (push-down-to-close) quickly without inserting the pin into the sleeve assembly. First, turn the handwheel to move the sleeve against the stem connector (key 22), then open the needle valve and turn the handwheel to force the valve plug closed. Figure 2. Operation Schematic sure above the piston decreases to move the piston upward. Without Positioner Piston movement is accomplished by loading air pressure on one side of the piston, and unloading the other side. Since no positioner is furnished, you must provide a loading device, such as a 4-way switching valve. This is not furnished with the actuator. Installation Inspect the equipment on arrival to note any damage which may have occurred in transit. The actuator is normally furnished mounted on a valve. Be sure the valve and connecting pipelines are free of foreign material. Install the valve with the flow in the direction of the arrow on the valve. The pressure connections made to the positioner are described in the 370 Series Instruction Manual. If a Type 491 actuator is being installed, the cylinder loading pressures should be supplied through a 4-way solenoid valve or a switching valve. If you purchase a 490 Series actuator separately, for field installation on a control valve, mount the actuator 3

4 on the valve and secure it to the bonnet with the eight bonnet-to-actuator bolts. The stem connection should then be made up to clamp the actuator stem and valve plug stem together to provide proper valve travel. This procedure is outlined in the Making Up Stem Connection section of these instructions. Maintenance Instructions are given below for complete disassembly of the actuator. When inspection or repair is necessary, disassemble the actuator only as far as is required to accomplish the job. 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 damage to property from sudden release of pressure or uncontrolled process fluid. Before you start disassembly: 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. Use bypass valves or completely shut off the process to isolate the valve from process pressure. Relieve process pressure on both sides of the valve. Drain the process media from both sides of the valve. Vent the power actuator loading pressure. Type 490 Key numbers used below are shown in the figure 3 assembly drawing. 1. Disconnect the cylinder tubing (key 47) from the cylinder (key 11) and positioner (key 1). 2. Break the stem connection by loosening the two locknuts (key 23) and removing the four cap screws from the stem connector. The feedback arm (key 4) and travel indicator (key 3) are also held in place by the four cap screws. 3. You can take the positioner off the unit by removing the machine screws (key ) and cable protector (key 2). Be sure to notice through which holes the cable strap is fastened to the feedback arm, then disconnect the cable strap from the feedback arm. Finally, unscrew the two cap screws that fasten the positioner to the yoke (key 1). Refer to the 370 Series Instruction Manual for any maintenance or adjustments that need to be made on the positioner. If the unit is operating properly and the cable windings on the cable spool are not changed, you can remount the unit without making any adjustments. 4. You can remove the cylinder (key 11) by unscrewing the four cap screws (key ) that fasten it to the yoke. Refer to the manufacturer s instruction manual for disassembly, maintenance and parts ordering instructions for the cylinder.. Reassemble the actuator in the reverse order of the above instructions. Be sure to attach the cable strap to the feedback arm in the same position as when it was removed. Refer to the section Making Up Stem Connection to properly attach the valve stem to the cylinder rod extension. Type 49 Key numbers used below are shown in the figure 4 assembly drawing. 1. Disconnect the cylinder tubing (key 47) from the cylinder (key 11) and positioner (key 1). 2. Disengage the locking pin (key ), if necessary. Then break the stem connection by loosening the two locknuts (key 23) and removing four cap screws from the stem connector. The feedback arm (key 4) and travel indicator (key 3) are also held in place by the four cap screws. 3. You can take the positioner (key 1) off the unit by removing the machine screws (key ) and cable protector (key 2). Be sure to notice through which holes the cable strap is fastened to the feedback arm, then disconnect the cable strap from the feedback arm. Finally, unscrew the two cap screws that fasten the positioner to the yoke (key 1). 4

5 Refer to the 370 Series Instruction Manual for any maintenance or adjustments that need to be made on the positioner. If the unit is operating properly and the cable windings on the cable spool are not changed, you can remount the unit without making any adjustments. 4. Unscrew the four cap screws (key ) that fasten the cylinder (key 11) to the handwheel extension (key ). Then pull the cylinder and piston rod extension out of the sleeve (key 9).. Unscrew the piston rod extension from the cylinder piston rod using a wrench on the cylinder piston rod flats to keep the two from turning together. Refer to the manufacturer s instruction manual for disassembly, maintenance and parts ordering instructions for the cylinder.. To continue disassembly, remove the six cap screws (key 13) in order to take off the handwheel extension. Be careful not to lose the key (key 2). 7. Loosen the set screws (key 3) in the gear case (key 1) and handwheel cap (key 3). Unscrew the handwheel cap and remove the handwheel (key 32).. Unscrew the worm retainers (keys 29 and 30) and rotate the worm shaft (key 31) to remove it from the gear case. 9. Unscrew the cap screws (key 44) and remove the gear case.. One thrust bearing (key 20) is now exposed. To expose the other thrust bearing, unscrew the gear (key 19) from the sleeve (key 9). The bearing retainer (key 21) sits on top of six set screws (key 27). If the gear case is just going to be repacked and no parts are changed which would change the free play in the bearings, you do not need to make any adjustment with the set screws. 11. Upon reassembly, pack the bearings (keys 20 and 40) with Phillips L-1 multi-purpose grease or equivalent. Apply Lubriplate (1) No. 130AA lubricant or equivalent to the surfaces of the sleeve and the bearing surfaces of the worm shaft (indicated by LP in figure 4.) Use the zerk fitting (key 37) for periodic lubrication after assembly.. Reassemble in the reverse order of the above steps observing the following points: a. Line up the key (key 2) with the slot in the sleeve on the side opposite the positioner. b. Be sure to attach the cable strap to the feedback arm in the same position as when it was removed. c. After the unit is reassembled, adjust the set screws (key 27), if necessary, to eliminate free play in the bearings. Lock the set screws in place with the hex nuts (key 41). Over-tightening the set screws will make handwheel operation difficult. Making Up Stem Connection The following procedure is for a push-down-to-close valve. The object of this procedure that should be applied to any other type of valve is that the stem connection must be made so that the valve strokes from full open to closed before the actuator reaches full stroke. CAUTION To avoid damaging the seating surfaces, do not rotate the valve plug while it is seated. Avoid damage to the valve plug stem by careful use of tools during travel adjustments. 1. With the valve assembled and actuator mounted, make sure the valve plug is in the closed position. Then turn the two stem locknuts (key 23) all the way onto the stem thread. 2. Starting with the cylinder fully retracted, manually or with air pressure extend the piston rod extension the specified valve travel. 3. Attach the stem connector (key 22), clamping the piston rod extension to the valve stem. Be sure you also attach the feedback arm (key 4) and travel indicator (key 3). 4. Cycle the actuator to check availability of desired total travel and that the valve plug seats before the cylinder reaches the end of its stroke. You can make minor travel adjustments, if necessary, by loosening the stem connector slightly, tightening the locknuts together, and (with the valve plug off the seat) screwing the stem either into or out of the stem connector by means of a wrench on the locknuts. 1. Trademark of Fiske Brothers Refining Co.

6 1A7204-B A719/IL Figure 3. Type 490 Actuator. If the total travel is adequate, tighten the stem connector securely, lock the stem locknuts against the connector, and adjust the indicator scale on the yoke to show valve plug position.. Provide a gauge, if necessary, to measure the pressure to the actuator. Make a final adjustment on the positioner to set the starting point of valve travel and to obtain full travel for the given instrument range. H or 7-inch diameter yoke boss, which refers to the actuator-to-valve mounting design. Some parts are also related to the piston rod or piston rod extension diameter. This measurement should be taken above the stem connector where the rod is full diameter. Parts Ordering Refer to the serial number when contacting your Fisher Controls sales office or sales representative for technical assistance or when ordering replacement parts. When ordering replacement parts, also be sure you include the 11-character part number for each part required from the following parts list. Parts List In the listing below, some parts are related to a -inch wide channel yoke leg or an -inch wide channel yoke leg. This refers to the size of the vertical channel iron member of the yoke. This is not to be confused with a Parts List Key Description Part Number 1 Yoke See following table 2 Cable Protector, galvanized steel 9- to -inch cylinder travel -inch channel yoke leg 2A2993X0 -inch channel yoke leg 2A297X0 13- to 1-inch cylinder travel -inch channel yoke leg 2A2992X0 -inch channel yoke leg 2A299X0 17- to 20-inch cylinder travel 2A2991X0 21- to 24-inch cylinder travel 2A2990X0 3 Travel Indicator, SST -inch channel yoke leg 11A719X0 -inch channel yoke leg 11A71X0 4 Feedback Arm, pl steel Type 490 -inch channel yoke leg 21A7X0 -inch channel yoke leg 21A711X0

7 Key Description Part Number 4 Anti-Rotator, steel Type 491 and 1-inch travel H inch yoke boss dia for size,,, and -inch cylinder 22A1X0 H inch yoke boss dia for size and -inch cylinder and 7-inch yoke boss dia for size to -inch cylinder 22A2X0 20 and 24-inch travel H and 7-inch yoke boss dia for size to -inch cylinder 22A2X0 Type 491-, 1, 20, and 24-inch travel for all cylinder sizes and all yoke boss sizes 22A2X0 Machine Screw, steel pl 9- to 1-inch travel ( req d) 17- to 24-inch travel (13 req d) 1A17292 Machine Screw, steel pl (for use w/ key 4 anti-rotator) and 1-inch travel (2 req d) 20 and 24-inch travel (3 req d) 1A17292 Washer, steel pl 9- to 1-inch travel ( req d) 17- to 24-inch travel ( req d) 1F Travel Scale, aluminum -7/ inch valve travel 31A713X0 9-7/ inch valve travel 31A7X0-7/ inch valve travel 31A71X0 11-7/ inch valve travel 31A71X0-7/ inch valve travel 31A717X0 13-7/ inch valve travel 31A71X0-7/ inch valve travel 31A719X0 1-7/ inch valve travel 31A7170X0 1-7/ inch valve travel 31A7171X0 17-7/ inch valve travel 31A7172X0 1-7/ inch valve travel 31A7173X0 19-7/ inch valve travel 31A7174X0 20-7/ inch valve travel 31A717X0 21-7/ inch valve travel 31A717X0 22-7/ inch valve travel 31A7177X0 23-7/ inch valve travel 31A717X0 Handwheel Extension see following table 9 Sleeve Assembly see following table Locking Pin, 41 SST 1-3/4 inch diameter rod 1J /2 inch diameter rod 11A7179X0 11 Air Cylinder Refer to the nameplate attached to the cylinder. Order all replacement parts for the cylinder from the cylinder manufacturer. Also, if the handwheel is specified, order its replacement parts from the cylinder manufacturer. When corresponding with the cylinder manufacturer, included the cylinder serial number, model number, and all other pertinent nameplate information. Pipe Plug, steel 0Z Cap Screw, plated steel ( req d) 1H211X00 Cap Screw, plated steel (4 req d) - and -inch cylinders 1H inch cylinder 11A7202X0 - and -inch cylinders 1P inch cylinder 11A7203X0 Key Description Part Number 1 Bushing (2 req d) -inch cylinder Malleable iron 1B292X00 31 stainless steel 1C3790X00 - and -inch cylinders Plated steel 1A3424X00A2 31 stainless steel 1A3424X and -inch cylinders Plated steel 1H stainless steel 1H17X00 -inch cylinder Plated steel 1H171X stainless steel 1H171X Nameplate, SST B0X0A2 17 Drive Screw, SST (4 req d) 1A Gear Case, cast iron 1-3/4 inch diameter rod 3H /2 inch diameter rod 31A717X0 19 Worm Gear, bronze 1-3/4 inch diameter rod 2H /2 inch diameter rod 21A71X0 20 Bearing (2 req d) 1-3/4 inch diameter rod 1H /2 inch diameter rod 11A7X0 21 Bearing Retainer, steel 1-3/4 inch diameter rod 1H /2 inch diameter rod 11A713X0 22 Stem Connector, 4 SST 1-3/4 inch diameter rod 1-inch diameter valve stem 21A7X0 1-1/4 inch diameter valve stem 21A71X0 2-inch diameter valve stem 21A7201X0 2-1/2 inch diameter rod 1-1/4 inch diameter valve stem 21A71X0 2-inch diameter valve stem 21A717X0 23 Hex Nut, plated steel (2 req d) 1-inch diameter valve stem 1C /4 inch diameter valve stem 0W inch diameter valve stem A220X0 24 Handwheel Indicator, SST 1J Chain, SST 1J Drive Screw, plated steel (2 req d) 1J Set Screw, steel ( req d) 1J Key, steel 1H Front Worm Retainer, steel 1H Back Worm Retainer, steel 1H Worm Shaft, steel 2H Handwheel, cast iron 3H Handgrip, steel 0U Handgrip bolt, steel 0U Handwheel Cap, cast iron 0W Set Screw, steel (3 req d) 1A Zerk Fitting 1A Ball, alloy steel 1A Spring, phosphor bronze 0D Ball Bearing (2 req d) 1H Hex Nut, plated steel ( req d) 1A Pointer, SST 21A7X0 43 Conduit Clamp 11A711X0 44 Cap Screw, plated steel ( req d) A9404X0 7

8 Key 1 Yoke, steel ACTUATOR YOKE BOSS CYLINDER CYLINDER TRAVEL, INCHES TYPE SIZE, INCHES DIA., INCHES (for use with Type 32L) 49 H 7 H 7 H 7 All All 41A707X0 41A700X0 41A704X0 41A70X0 41A7092X0 41A709X0 41A70X0 41A74X0 41A7X0 41A71X0 41A711X0 41A70X0 3A41X0 3A41X02 3A41X092 3A41X132 3A41X172 3A41X2 3A41X22 3A41X292 3A41X332 3A41X372 3A41X4 3A41X42 41A7047X0 41A701X0 41A7077X0 41A701X0 41A70X0 41A709X0 41A7093X0 41A7097X0 41A71X0 41A7X0 41A79X0 41A7113X0 41A7117X0 41A71X0 3A41X022 3A41X02 3A41X2 3A41X2 3A41X 3A41X222 3A41X22 3A41X302 3A41X342 3A41X32 3A41X422 3A41X42 41A704X0 41A702X0 41A707X0 41A702X0 41A70X0 41A7090X0 41A7094X0 41A709X0 41A72X0 41A7X0 41A71X0 41A71X0 41A711X0 41A72X0 3A41X032 3A41X072 3A41X1 3A41X 3A41X192 3A41X232 3A41X272 3A41X3 3A41X32 3A41X392 3A41X432 3A41X472 41A7049X0 41A703X0 41A7079X0 41A703X0 41A707X0 41A7091X0 41A709X0 41A7099X0 41A73X0 41A77X0 41A7111X0 41A711X0 41A7119X0 41A73X0 3A41X042 3A41X02 3A41X2 3A41X 3A41X202 3A41X242 3A41X22 3A41X322 3A41X32 3A41X402 3A41X442 3A41X42 41A700X0 41A704X0 Key Description Part Number 4 Machine Screw, plated steel (2 req d) 1J492 4 Machine Screw, plated steel 1A Tubing, copper (specify length) W 49 Connector, brass (2 req d) 1H Elbow, brass (2 req d) 1L Positioner see Instruction Manual, 370 Series Pneumatic Valve Positioners 2 Machine Screw, SST 1F Lock Washer, SST 1A Needle Valve Brass 1F Steel 1F Pipe Nipple, steel (3 req d) 1C Pipe Tee, steel (2 req d) 1C Key Handwheel Extension, steel CYLINDER CYLINDER TRAVEL, INCHES DIA., INCHES A709X0 41A7070X0 41A7071X0 41A709X022 41A7070X022 41A7071X022 41A709X032 41A7070X032 41A7071X032 41A709X042 41A7070X042 41A7071X042 41A7072X0 41A7074X0 41A707X0 41A7072X022 41A7074X022 41A707X022 41A7073X0 41A7074X032 41A707X032 41A7073X022 41A7074X042 41A707X042 Key 9 Sleeve Assembly, steel CYLINDER CYLINDER TRAVEL, INCHES DIA., INCHES A7X0 21A7X0 21A7X0 21A7X022 21A7X022 21A7X022 21A7X032 21A7X032 21A7X032 21A7X042 21A7X042 21A7X042 21A7X0 21A79X0 21A79X0 21A7X022 21A79X022 21A79X022 21A79X032 21A79X032 21A7X032 21A79X042 21A79X042 21A79X042

9 1A720-B A7/IL Figure 4. Type 49 Actuator 9

10 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. Fisher Controls International, Inc. 1974, 1992; All Rights Reserved The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. We reserve the right to modify or improve the designs or specifications of such products at any time without notice. For information, contact Fisher Controls: Marshalltown, Iowa 01 USA Cernay 700 France Sao Paulo 0424 Brazil Singapore 41 Printed in U.S.A.