Fisher 657 User Manual

Instruction Manual

D100307X012

Fisherr 657 Diaphragm Actuators Size 80 and 100

657 Size 80 and 100 Actuators

December 2010

Contents

Introduction 1.................................

Scope of Manual 1.............................

Description 2.................................

Specifications 3...............................

Installation 3...................................

Actuator Mounting 3...........................

Loading Connection 4......................

Adjustments 4.................................

Travel 4......................................

Spring 5.....................................

Size 80 5.................................

Size 100 5................................

Maintenance 7.................................

Actuator 7...................................

Size 80 Disassembly 7......................

Size 80 Assembly 8.........................

Size 100 Disassembly 10....................

Size 100 Assembly 11.......................

Size 80 Side‐Mounted Handwheel 12.............

Disassembly 12............................

Assembly 13..............................

Size 80 Hydraulic Snubber 13....................

Size 80 Top‐Mounted Handwheel

(Adjustable Up Travel Stop) 13................

Disassembly 14............................

Assembly 14..............................

Size 100 Top‐Mounted Handwheel

(Adjustable Up Travel Stop) 14................

Disassembly 15............................

Figure 1. Sectional view of Fisher 657 Size 100 Actuator

W0366‐1

Assembly 15..............................

Parts Ordering 15...............................

Parts List 16...................................

Introduction

Scope of Manual

This instruction manual provides information on installation, adjustment, maintenance, and parts ordering for the Fisher 657 actuator in sizes 80 and 100. Refer to separate instruction manuals for information about other equipment and accessories used with these actuators.

Do not install, operate, or maintain 657 actuators without being fully trained and qualified in valve, actuator, and accessory installation, operation, and maintenance. To avoid personal injury or property damage, it is important to carefully read, understand, and follow all the contents of this manual, including all safety cautions and warnings. If you have any questions about these instructions, contact your Emerson Process Management sales office before proceeding.

www.Fisher.com

657 Size 80 and 100 Actuators

December 2010

Table 1. Specifications

SPECIFICATIONS

Nominal Effective Diaphragm Area

Yoke Boss Diameters

Acceptable Valve Stem Diameters

Maximum Allowable Output Thrust

Maximum Travel

Maximum Casing Pressure for Actuator Sizing

Maximum Diaphragm Casing Pressure

Material Temperature Capabilities

Pressure Connections 1/4 NPT internal

Approximate Weights Without Handwheel

1. Heavy actuator‐to‐bonnet bolting.

2. This maximum casing pressure is not to be used for normal operating pressure.

(2)

Instruction Manual

D100307X012

ACTUATOR SIZE

inch

mm 127 127 178 inch 5 5H mm 25.4 or 31.8 31.8 50.8 inch 1 or 1‐1/4 1‐1/4 2

Standard Cast Iron

Construction N 62942 88075 200170 lb 14150 19800 45000

mm 76 102 inch 3 4

Standard Cast Iron

Construction

bar 3.4 4.9 6.9

psig 50 70 100

bar 4.1 5.5 7.9

psig 60 80 115

_C -40 to 82 _F -40 to 180

kg 234 346

lb 515 762

80 100

1761 2902

273 450

(1)

All Steel

Construction

All Steel

Construction

Figure 2. Schematic Representation of Fisher 657 Actuator

AIR PUSHES STEM DOWN

SPRING LIFTS

AF3833‐A A0792‐2

Description

The 657 actuator (figure 1) is a direct‐acting, spring‐opposed diaphragm actuator used for automatic operation of control valves. The actuator positions the valve plug in response to varying pneumatic loading pressure on the diaphragm. Figure 2 shows the operation of these actuators.

A 657 actuator can be furnished with either a top‐mounted or side‐mounted (size 80 only) handwheel assembly. A top‐mounted handwheel assembly is normally used as an adjustable‐up travel stop. The size 100 top‐mounted

Instruction Manual

D100307X012

handwheel may be used as an auxiliary manual actuator. A side‐mounted handwheel assembly is normally used as an auxiliary manual actuator.

657 Size 80 and 100 Actuators

December 2010

Specifications

Refer to table 1 for specifications of the 657 actuator. See the actuator nameplate for information about a specific actuator.

Maximum Pressure Limitations

The casing and diaphragm of 657 actuators are pressure operated. The air pressure provides force to compress the spring and stroke the actuator. The following explanations describe the maximum pressure limitation for 657 actuators. Refer to the nameplate, warning tag, and table 1 for maximum values.

D Maximum Casing Pressure for Actuator Sizing: This is defined as the maximum pressure that can be applied to

stroke the actuator, overcome unbalance forces, and provide seat load.

D Maximum Diaphragm Casing Pressure: If the maximum diaphragm casing pressure is exceeded, damage to the

diaphragm, casing, or actuator may result. This pressure is not to be used for normal operating pressure.

WARNING

To avoid personal injury or parts damage, do not exceed the Maximum Diaphragm Casing Pressure listed in table 1. The Maximum Diaphragm Casing Pressure must not produce a force on the actuator stem greater than the maximum allowable actuator output thrust or the maximum allowable stem load.

Installation

WARNING

Always wear protective gloves, clothing, and eyewear when performing any installation operations to avoid personal injury.

Check with your process or safety engineer for any additional measures that must be taken to protect against process media.

If installing into an existing application, also refer to the WARNING at the beginning of the Maintenance section in this instruction manual.

When an actuator and valve body are shipped together, the actuator is normally mounted on the valve. Follow the valve body instructions when installing the control valve in the pipeline. If the actuator is shipped separately or if it is necessary to mount the actuator on the valve, perform the Actuator Mounting procedures as described below.

For information on mounting valve positioners, refer to the appropriate valve positioner instruction manual.

Actuator Mounting

1. To permit adjustment of the actuator spring, the size 100 actuator must be installed in a vertical position above the valve body. Mount the actuator on the valve bonnet. Insert the cap screws, and tighten the hex nuts, securing the actuator to the bonnet.

657 Size 80 and 100 Actuators

December 2010

2. Screw valve stem locknuts (key 16, figure 4) all the way onto valve stem thread.

3. Connect an air supply to the diaphragm casing.

4. For push‐down‐to‐close valves, be sure the valve plug is on its seat. Apply pressure to ensure that the actuator stem is fully extended. Reduce actuator loading pressure to retract the stem approximately 3.2 mm (1/8‐inch).

5. For push‐down‐to‐open valves, move valve plug to closed position. On large body sizes, this may require the use of a pry bar inserted through the body line opening. If the body is installed in a pipeline, the bottom flange (if one is used) can be removed and the valve plug pushed to the seat from the bottom opening. Pressure the actuator to move the stem out 3.2 mm (1/8‐inch).

Instruction Manual

D100307X012

WARNING

To avoid personal injury due to the sudden uncontrolled movement of parts, do not loosen the stem connector cap screws when the stem connector has spring or loading pressure force applied to it.

CAUTION

Incomplete engagement of both valve stem and actuator stem in the stem connector can result in stripped threads or improper operation. Be sure that the length of each stem clamped in the stem connector is equal to or greater than the diameter of that stem.

6. Clamp the actuator and valve plug stems between the two stem connector halves (key 26, figure 4). Insert and tighten the stem connector cap screws.

7. Thread the stem locknuts against the stem connector.

8. Align the travel indicator scale (key 18, figures 4 and 5) to show valve position.

Loading Connection

1. Connect the loading pressure piping to the connection in the top of the diaphragm casing.

2. Remove the 1/4‐inch bushing (key 33, figure 4 and key 120, figure 5) to increase connection size, if necessary. The connection can be made with either piping or tubing.

3. Keep the length of tubing or piping as short as possible to avoid transmission lag in the control signal. If an accessory (such as a volume booster or valve positioner) is used, be sure that the accessory is properly connected to the actuator. Refer to the positioner instruction manual as necessary.

4. Cycle the actuator several times to check that the valve stem travel is correct and that the travel occurs when the correct pressure range is applied to the diaphragm.

5. If valve stem travel is incorrect, refer to the Travel procedure in the Adjustments section.

6. If the pressure range is incorrect, refer to the Spring procedure in the Adjustments section.

Adjustments

Travel

Make travel adjustments when the motion observed during actuator travel is different from the travel stamped on the actuator nameplate. If the Actuator Mounting procedure was followed correctly, this adjustment should not be necessary.

Instruction Manual

D100307X012

When adjusting travel of a reverse‐acting (push‐down‐to‐open) valve, apply a slight pressure on the actuator diaphragm. This moves the valve plug off the seat, reducing the chance of damaging the valve plug or seat during adjustments.

1. Back the stem locknuts away from the stem connector, and slightly loosen the stem connector cap screws.

657 Size 80 and 100 Actuators

December 2010

CAUTION

Do not use wrenches or other tools directly on the valve stem. Damage to the stem surface and subsequent damage to the valve packing may result.

2. Tighten the locknuts together, using a wrench, then screw the valve stem either into the stem connector to lengthen travel or out of the stem connector to shorten travel.

3. Cycle the actuator to check the travel. If actual travel is not equal to the specified travel, adjust and check travel until correct. Tighten the stem connector cap screws when correct travel is obtained.

4. Raise the travel indicator disk by threading the stem locknuts against the stem connector.

Spring

Make spring adjustments when the loading pressure range applied to achieve specified travel is not equal to the pressure range stamped on the actuator nameplate. Refer to the Bench Set pressure range on the nameplate when the valve contains no pressure and the packing is loosely inserted in the bonnet. Refer to the Max. Allow. Supply on the nameplate when the valve is controlling the specified pressure drop and the packing is tightened to stop leaks around the stem.

Monitor loading pressure carefully when making adjustments. Do not exceed the pressure specifications of either the loading regulator or the actuator casings.

Each actuator spring has a fixed pressure span. Changing the spring compression shifts the span up or down to make valve travel coincide with the loading pressure range.

Size 80

Remove cover band (key 60, figure 4), insert a rod of approximately 12.7 mm (1/2‐inch) diameter into a hole in the adjusting screw (key 12, figure 4), and rotate the adjusting screw with the rod. Rotating the screw from left to right will increase the loading pressure required to start actuator stem travel; opposite rotation will decrease the pressure required to start travel.

Size 100

CAUTION

The actuator must be in the vertical position when adjusting spring to avoid damage to thrust bearing (key 35, figure 5) and to properly position spacers required for adjustment.

Remove the shroud plate (key 107, figure 5), and loosen the jam nut (key 115, figure 5).

657 Size 80 and 100 Actuators

December 2010

Figure 3. Dimension B for Spring Adjustment

JAM NUT

ADJUSTING NUT

A0950‐1

Instruction Manual

D100307X012

SPRING SEAT

LOWER DIAPHRAGM CASING

For small spring forces, adjustments can be made by rotating the adjusting nut (key 114, figure 5). Clockwise rotation (when viewed from diaphragm casings) of the adjusting nut will increase the loading pressure required to start actuator stem travel, and counterclockwise rotation will decrease the pressure required to start travel. Tighten the jam nut when adjustment is complete.

For high spring forces, it is necessary to use spacers between the lower diaphragm casing and the spring seat to isolate spring force from the adjusting nut.

WARNING

To avoid personal injury from the compressed actuator spring snapping back to its original length, make and use the spacers by following the instructions in the steps below.

To avoid personal injury, keep hands and tools away from the spring and spring seat as instructed in the following procedure.

1. It is recommended that three spacers be made of 3‐inch schedule 80 pipe cut to the appropriate length specified in step 2. If other than the recommended material is to be used, be certain that the spacers are capable of withstanding the spring force involved. The spacers must be of equal length with ends cut squarely.

2. Measure dimension B as shown in figure 3. Cut length of spacers as follows:

a. If it is desired to decrease spring compression, make the spacers approximately 4.8 mm (3/16‐inch) longer than

dimension B.

b. If it is desired to increase spring compression, make the spacers approximately 4.8 mm (3/16‐inch) shorter than

either dimension B plus the amount of adjustment required or dimension B plus valve travel, whichever is less.

3. Whenever the total amount of adjustment required is greater than valve travel, the adjustment must be made in two or more steps, and the amount of adjustment taken in each step must be less than valve travel.

4. Pressure the actuator to attain full travel. Cautiously insert the spacers at equal intervals around the spring seat (key 11, figure 5). The spacers must be seated squarely when in use or they may slip out of position. Keeping hands and

Instruction Manual

D100307X012

657 Size 80 and 100 Actuators

December 2010

tools away from the spring and spring seat, slowly decrease loading pressure until the spring force holds the spacers firmly between the spring seat and lower diaphragm casing (key 5, figure 5).

5. Loosen the jam nut. The adjusting nut can now be rotated clockwise (when viewed from the diaphragm casings) to increase the loading pressure required to start actuator stem travel or counterclockwise to decrease the pressure required to start travel.

6. Pressure the actuator to move the spring seat away from the spacers, and carefully remove the spacers.

7. If the total adjustment required was greater than valve travel, repeat the procedure. It will be necessary to make new spacers using the new dimension B and the remaining adjustment required or valve travel, whichever is less. Tighten the jam nut when adjustment is complete.

Maintenance

WARNING

Avoid personal injury or property damage from sudden release of process pressure or bursting of parts. Before performing any maintenance operations:

D Do not remove the actuator from the valve while the valve is still pressurized.

D Always wear protective gloves, clothing, and eyewear when performing any maintenance operations to avoid personal

injury.

D 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.

D 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. Drain the process media from both sides of the valve.

D Vent the power actuator loading pressure and relieve any actuator spring precompression.

D Use lock‐out procedures to be sure that the above measures stay in effect while you work on the equipment.

D The valve packing box may contain process fluids that are pressurized, even when the valve has been removed from the

pipeline. Process fluids may spray out under pressure when removing the packing hardware or packing rings, or when loosening the packing box pipe plug.

D Check with your process or safety engineer for any additional measures that must be taken to protect against process

media.

The maintenance instructions are divided into four sections: actuator (sizes 80 and 100); side‐mounted handwheel assembly (manual operator); hydraulic snubber; and top‐mounted handwheel assembly (adjustable‐up travel stop).

Actuator

This procedure describes how the actuator can be completely disassembled and assembled. When inspection or repairs are required, disassemble only those parts necessary to accomplish the job; then, start the assembly at the appropriate step.

Key numbers refer to figure 4 for size 80 actuators and figure 5 for size 100 actuators.

Size 80 Disassembly

1. Bypass the control valve. Reduce the loading pressure to atmospheric, and remove the tubing or piping from the top of the diaphragm casing (key 1).

657 Size 80 and 100 Actuators

December 2010

Instruction Manual

D100307X012

WARNING

To avoid personal injury from the precompressed spring force thrusting the upper diaphragm casing (key 1) away from the actuator, relieve spring compression (step 2, below), and carefully remove casing cap screws (key 22) (step 4, below).

2. Remove cover band (key 60). Insert a rod of approximately 12.7 mm (1/2‐inch) diameter into a hole in the adjusting screw (key 12), and rotate the adjusting screw from right to left until spring compression is relieved. If the actuator has a handwheel, rotate it counterclockwise, relieving all spring compression.

3. If necessary, the entire actuator may be removed from the valve body by unscrewing two cap screws from stem connector (key 26) and removing actuator‐to‐bonnet bolting.

4. Unscrew diaphragm casing cap screws and nuts (keys 22 and 23), and lift off upper diaphragm casing (key 1).

5. Remove the molded diaphragm (key 2).

6. For actuators without snubber, remove diaphragm plate and stem (keys 4 and 10) as an assembly. This assembly can be broken down further, if necessary, by removing the cap screw (key 3).

7. For actuators with snubber (see figure 7), unscrew cap screw (key 3), and remove diaphragm plate (key 4). Remove stem connector (key 26). Unscrew cap screws (key 85), and remove cylinder assembly (key 74) and attached stem and upper seat (keys 10 and 90) from actuator.

To disassemble snubber:

a. Unscrew stem from piston/piston rod assembly (key 27).

b. Remove retaining rings, cylinder heads, and piston/piston rod assembly (keys 76, 75, and 27). Replace packing

and O‐rings (keys 103, 104, 77 and 105) as required.

8. Remove actuator spring, upper sleeve, and spring seat (keys 6, 34 and 11).

9. Unscrew cap screws and nuts (keys 62 and 63), and remove spring case (key 29). Cap screws (key 62) on units with side‐mounted handwheel do not use hex nuts (key 63).

10. For actuators without side‐mounted handwheel, remove adjusting flange (key 36) and attached thrust bearing and adjusting screw (keys 35 and 12).

11. For actuators with side‐mounted handwheel (see figure 7), unscrew cap screws (key 64), and remove adjusting flange (key 36) and attached thrust bearing and adjusting screw (keys 35 and 12). Do not lose the key (key 47).

Size 80 Assembly

1. Coat the threads of the adjusting flange (key 36) with anti‐seize lubricant (key 244). Replace the adjusting flange, adjusting screw, and thrust bearing (keys 36, 12, and 35). Pack bearing with lithium grease lubricant (key 241).

For actuators with side‐mounted handwheel, install the key (key 47) on the adjusting flange (key 36). Coat the adjusting flange threads with anti‐seize lubricant. Install the adjusting flange so that the key engages the slot in the lower sleeve. Secure adjusting flange with cap screws (key 64). Adjust set screws (key 40, figure 7) to eliminate free play in handwheel bearings.

Note

Over‐tightening the set screws will make handwheel operation difficult.

2. Mount the spring case (key 29) to the yoke (key 9) using cap screws and hex nuts (keys 62 and 63).

+ 16 hidden pages