Valtek Auxiliary Handwheels
and Limit Stops
Table of Contents
Page
1General information
2Installation
2Side-mounted handwheels, size 25 and 50 (linear actuators)
3Side-mounted handwheels, size 100 and 200 (linear actuators)
6Top-mounted, continuously connected handwheels, Size 100 and 200 (linear actuators)
7Top-mounted, push-only handwheels (linear actuators)
9 Declutchable handwheels (rotary actuators)
11 Push-only limit stops (linear actuators)
11 Pull-only limit stops (linear actuators)
GENERAL INFORMATION
The following instructions are designed to assist in installing, operating, performing maintenance and disassembling handwheels and limit stops mounted on Valtek spring cylinder actuators. Product users and maintenance personnel should thoroughly review this bulletin in conjunction with the Valtek Installation, Operation, Maintenance Instructions for Cylinder Actuators (IOM 2), prior to working on the handwheels and limit stops.
To avoid possible injury to personnel or damage to valve parts, WARNING and CAUTION notes must be strictly adhered to. Modifying this product, substituting non-factory parts, or using maintenance procedures other than outlined could drastically affect performance, be hazardous to personnel and equipment, and may void existing warranties.
WARNING: Standard industry safety practices must be adhered to when working on this, or any other, process control product. Specifically, personal protective and lifting devices must be used as warranted.
Valtek control valves are often equipped with auxiliary handwheels of the continuously connected or push-only type, allowing for manual operation of the valve in case of air failure. Continuously connected handwheels can also be used as a limit stop to limit valve travel in either the open or closed position. Push-only handwheels are designed to close the valve or limit opening. Limit stops limit the actuator stroke in one direction or the other.
INSTALLATION
Valtek control valves, equipped with auxiliary handwheels and limit stops, are installed as outlined in the maintenance bulletin for each type of valve. Refer to the sales catalog or certified dimensional drawing for estimated overhead clearance requirements. To allow for manual operation and maintenance, adequate access to the handwheel or limit stop must be provided.
SIDE-MOUNTED, CONTINUOUSLY CONNECTED HANDWHEELS, SIZE 25 AND 50 (Linear Actuators)
Operation
If air failure should occur, or if manual control of the valve is desired, the side-mounted, continuously connected handwheel can be operated as follows:
1.Set the three-way bypass valve (located on the supply line to the positioner) to 'manual' to vent the air pressure from the actuator.
NOTE: Three-way valves are installed in the supply line only when there is no lock-up system or volume tank. On volume tank or lock-in-place systems, the
Rev. 6/93 Valtek No. 49015 © 1998 Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611 |
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bypass valve is located between the top and bottom cylinder ports.
2.To open the valve, turn the handwheel counterclockwise to retract the plug.
3.To close the valve, turn the handwheel clockwise to extend the plug.
4.To return the valve to automatic control, return the handwheel nut to 'neutral' as shown by the handwheel position indicator and set the three-way bypass valve to 'auto.'
5.Adjusting the handwheel nut to a position other than neutral provides a limit stop function, either limiting opening or closing.
Maintenance
For proper operation of the handwheel, maintain a coat of multi-purpose lubricant on the bearings at all times. To do this:
1.Locate the two zerk fittings on the handwheel housing. One fitting lubricates both bearings simultaneously.
NOTE: The screw and nut threads are permanently Iubricated with a solid film lubricant, requiring no additional Iubrication.
2.Check all pivot points for wear and replace worn or damaged parts as necessary. Lubricate all pivot points.
3.Keep screw, nut and bearings free from dirt at all times. If dirt or grease builds up so that handwheel operation is impaired, disassemble handwheel and clean thoroughly.
Disassembly
To disassemble the side-mounted handwheel assembly on size 25 and 50 linear actuators, refer to Figure 1.
NOTE: Because of the handwheel’s modular design, the handwheel assembly can be removed from the actuator without affecting the valve’s operation (unless the handwheel is being used as a limit stop).
CAUTION: Prior to removing the handwheel unit, ensure that the handwheel is not functioning as a limit stop before removing the housing bolts. Failure to do so could cause serious personal injury. If the actuator remains in service during handwheel disassembly, keep hands and clothes away from moving parts to avoid injury.
1.Remove four housing bolts and lift handwheel assembly off the yoke.
2.Loosen the crank levers by removing two sets of spacers, bolts and nuts fastening the levers together. Remove one retaining ring from the pivot pin and push the pin out.
3.Remove the lock nut, handwheel and Woodruff key from the handwheel screw shaft.
4.Remove the internal retaining ring with a pair of internal snap-ring pliers.
5.Remove the handwheel screw shaft from the handwheel nut by turning shaft clockwise (the screw has left-hand threads). After the shaft is free from the nut, pull the shaft and bearings straight out and remove nut and crank levers from the housing.
6.After removing the support spacer, slide the two bearings and support washer (sandwiched between the bearings) off the handwheel screw shaft.
Reassembly
To reassemble the side-mounted handwheel on size 25 and 50 linear actuators:
1.Inspect all parts, especially the bearings, for damage or wear; clean all parts and lubricate each bearing.
2.Replace the bearings on the shaft in the following order: bearing, support washer, bearing, support spacer.
NOTE: The bearings must be oriented with the largest inside races (thrust supporting) facing each other, with a support washer between them (refer to Figure 1).
CAUTION: If the bearing orientation is incorrect, the bearings will be damaged.
3.Position the handwheel nut between the two lever cranks and reinstall the handwheel nut into the housing. Make sure the position indicator pin on the nut is inserted in the position indicator slot.
4.Lubricate the small tip on the handwheel shaft and mating hole in the housing. Reinsert the handwheel shaft into the housing and begin turning the screw counter-clockwise into the handwheel nut. Continue to turn until the bearings are seated in the housing and the nut is in the neutral position.
5.Install the internal retaining ring to hold the bearings in the housing.
6.Replace the handwheel on the shaft, making sure the Woodruff key is properly inserted in key slot.
7.Fasten the handwheel securely in position with the lock nut.
NOTE: If there is excessive movement ( 1/8-inch or more) when pulling on the handwheel screw, the bearings are positioned backwards and must be reversed (refer to Step 2) before bearing damage occurs.
8.Lubricate and reinsert pivot pin and fasten with retaining ring. Bolt the two sides of the crank levers together, using two sets of spacers, bolts and nuts.
9.Reattach the handwheel assembly to the yoke using four housing bolts. Make sure the slotted ends of the lever cranks mate with the actuator stem pin.
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Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611 |
Handwheel
(Item No. 393-18)
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Locking Bar |
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Internal Retaining |
(Item No. 393-17) |
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Ring |
Pin |
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(Item No. 393-9) |
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(Item No. 393-1) |
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Support Spacer |
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(Item No. 393-6) |
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Handwheel |
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Screw Shaft |
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(Item No. 393-13) |
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Lock Nut |
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(Item No. 393-4) |
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Key |
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(Item No. 393-5) |
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Not Shown: |
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Grease Fittings |
Pivot Pin |
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(Item No. 393-15) |
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Indicator Plate |
(Item No. 393-19) |
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External Retaining Ring |
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(Item No. 393-12) |
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Indicator Plate Screws |
(Item No. 393-20) |
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(Item No. 401) |
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Bearings
(Item No. 393-8)
Support Washer
(Item No. 393-10)
Housing
(Item No. 393-14)
Housing Bolt
(Item No. 333)
Handwheel Nut
(Item No. 393-16)
Spacer (Item No. 393-7)
Nut (Item No. 393-3)
Bolt (Item No. 393-2)
Actuator Stem
(Item No. 211)
Actuator Pin
(Item No. 372)
Crank Lever
(Item No. 393-11)
Figure 1: Size 25 and 50, Side-mounted, Continuously connected Handwheel
NOTE: Item numbers shown above correspond directly to valve’s bill of material. Refer to the bill of material for specific part numbers.
CAUTION: Avoid reattaching the handwheel assembly to the yoke while the actuator remains in service. If the actuator remains in service during handwheel reassembIy, ensure that the handwheel is in the neutral position and that hands and clothes are kept away from moving parts to avoid injury.
SIDE-MOUNTED, CONTINUOUSLY CONNECTED HANDWHEELS, SIZE 100 AND 200 (Linear Actuators only)
Operation
See 'Operation' under Size 25 and 50 Side-mounted Handwheels section.
Maintenance
Because the screw threads are permanently lubricated with a solid film lubricant, periodical lubrication is not
necessary; however, periodically examine the handwheel assembly:
1.Check bearing wear by pulling on the handwheel. If movement more than 1/8-inch in any one direction is present disassemble and inspect bearings.
2.Keep the handwheel mechanism free from dirt. If dirt begins to impair handwheel operation, disassemble and clean thoroughly.
Disassembly
To disassemble the side-mounted handwheel on size 100 and 200 linear actuators, refer to Figure 2:
1.Depressurize the process line and actuator to atmospheric pressure. Remove the actuator from valve (see valve’s maintenance bulletin for instructions). Disassemble cylinder by following steps 1-6 under 'Disassembling Actuator' instructions found in IOM 2 (Cylinder Actuators).
Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611 |
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WARNING: Failure to repressurize process line and actuator to atmospheric pressure could result in serious personaI injury.
2.Slide the stem clamp and bellows off the actuator stem.
3.Remove the bolt holding the handwheel to the pinion shaft. Slide handwheel off pinion shaft.
4.Remove the housing set screw at the base of the handwheel housing and the retaining ring Iock screw which releases the compression on the handwheel housing retaining ring.
5.Using two screwdrivers, remove the handwheel housing retaining ring.
6.Pull the handwheel assembly off the yoke, taking care not to gall the actuator stem O-ring as it is pulled from yoke.
7.With the cylinder and piston removed (Step 1), pull actuator stem straight out of the housing.
8.Remove the bearing spacer, lower bearing and handwheel nut from the actuator stem.
9.To remove the pinion gear and shaft, remove the pin retaining ring, rotate the pinion shaft so the pin will not hit the indicator gear bearing, and push the pin out. Slide the pinion shaft out of the pinion gear and housing.
10.Remove the bevel gear, wave spring and the upper thrust bearing.
11.If the pinion shaft bearings are worn or damaged, push them out with a suitable press and a dowel the same size as the bearing’s outside diameter.
12.Remove the upper actuator stem O-ring. (It is not necessary to remove the O-ring retaining ring and O-ring retaining washer).
13.The indicator cover plate is attached to the housing with an adhesive gasket. Gently pry it off.
14.With a screwdriver, remove the two carriage screws holding the position indicator assembly to the housing. Remove assembly from housing.
15.Normally the position indicator assembly does not require disassembly. If disassembly is required, remove the inside stem retaining ring located on the lower end on the indicator stem. Screw the stem out of the indicator nut.
Reassembly
To reassemble the side-mounted handwheel on Size 100 and 200 Iinear actuators:
1.Replace and lubricate all O-rings with a silicone lubricant (Dow Corning® 55M or equivalent). Clean all internal parts thoroughly before beginning assembly.
2.Insert upper actuator stem O-ring and replace O-ring retaining washer and retaining ring.
3.If the pinion shaft bearings have been removed, press in two new bearings with a dowel of the same diameter, using a suitable press.
4.To install the bevel gear and bearings, place the handwheel housing upside down. Lubricate the upper ball thrust bearing and place it in the housing, squarely on the machined shoulder.
5.Lubricate the bevel gear thoroughly on the teeth and the outer surface where it makes contact with the housing. Lubricate the inside of the square drive tube. Position the bevel gear assembly into the housing.
6.Lubricate the pinion gear, shaft and thrust bearings. Reposition the pinion gear and thrust bearings. Slide the pinion shaft through the outside of the housing until it mates with the pinion gear. Rotate the shaft until the hole in the pinion gear aligns with the shaft. Insert pin and replace pin retaining ring.
7.Screw the handwheel nut midway onto the actuator stem and insert the stem through the center of the bevel gear. Be careful not to score the polished surfaces of the actuator stem.
8.Position the wave spring on the shoulder of the bevel gear. Lubricate the lower ball thrust bearing and place it on the wave spring. Make sure the bearing fits into the step in the bevel gear with the wave spring sandwiched in between. Replace the bearing spacer with the bearing fitting inside the spacer’s lip.
9.After replacing the lower actuator stem O-ring in the yoke, insert the yoke into the housing, taking care not to gall the actuator stem on the stem bushings or damage the O-ring.
10.Using two screwdrivers, replace the housing retaining ring.
11.Rotate the housing to the desired orientation and screw-in the retaining ring Iockscrew and reinstall the housing setscrew until the retaining ring and housing are locked securely in place.
12.Reinstall the handwheel and handwheel bolt onto the pinion shaft. Fasten securely with nut.
13.Reassemble the position indicator assembly by inserting the indicator stem onto the carriage. Screw the indicator nut into the stem. Replace the stem retaining ring. Turn the stem until the indicator nut is centered between the two neutral marks stamped on the carriage.
14.Turn the handwheel counter-clockwise until the actuator stem begins to retract. Turn the handwheel clockwise for two complete turns, so that the handwheel nut is in the neutral position.
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Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611 |
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