Yarway Forged Steel Gate Valves, Series 950 IOM Owner's manual

Brand: Yarway

Model: Forged Steel Gate Valves, Series 950 IOM

Type: Owner's manual

Before installation these instructions must be fully read and understood

YARWAY MODEL 950 HANCOCK FORGED STEEL GATE VALVE

InstallatIon and maIntenance InstructIons

VCIOM-03223-EN 18/02

1 SAFETY NOTICE

Proper installation, operation and maintenance

is essential to the safe and reliable operation

of all valve products. The relevant procedures

described in this manual, are effective methods

of performing the required tasks. Some of

these procedures require the use of tools

specifically designed for an intended purpose.

These special tools should be used when, and

as, recommended.

It is important to note that this manual contains

various “safety messages” which should be

carefully read in order to minimize the risk of

personal injury, or the possibility that improper

procedures will be followed which may damage

the product, or render it unsafe. It is also

important that these “safety messages” are

not exhaustive.

PRODUCT SAFETY SIGN AND LABEL SYSTEM

If and when required, appropriate safety labels

have been included in the rectangular margin

blocks throughout this manual. Safety labels

are vertically oriented rectangles as shown in

the representative examples (below), consisting

of three panels encircled by a narrow border.

The panels can contain four messages which

communicate:

• The level of hazard seriousness

• The nature of the hazard

• The consequence of human, or product,

interaction with the hazard.

• The instructions, if necessary, on how to

avoid the hazard.

The top panel of the format contains a signal

word (DANGER, WARNING, CAUTION or

ATTENTION) which communicates the level of

hazard seriousness.

The center panel contains a pictorial which

communicates the nature of the hazard, and

the possible consequence of human or product

interaction with the hazard. In some instances

of human hazards the pictorial may, instead,

depict what preventive measures to take, such

as wearing protective equipment.

The bottom panel may contain an instruction

message on how to avoid the hazard, this

message may also contain a more precise

definition of the hazard, and the consequences

of human interaction with the hazard, than can

be communicated solely by the pictorial.

DANGER

Do not remove bolts if pressure in line, as this will

result in severe personal injury or death.

WARNING

Know all valve exhaust/leakage points to avoid

possible severe personal injury or death.

CAUTION

Wear necessary protective equipment to preven

possible injury.

ATTENTION

Do not drop or strike valve.

Emerson can not possibly know, evaluate, and

advise any customer of all the conceivable ways

in which tasks might be performed, or of the

possible hazardous consequences of each way.

Consequently, Emerson has not undertaken

any such broad evaluation and, thus, anyone

who uses a procedure and/or tool, which is

not recommended by Emerson, or deviates

from Emerson recommendations, must be

thoroughly satisfied that neither personal

safety, nor valve safety, will be jeopardized

by the method and/or tools selected. If not

so satisfied, contact Emerson representative

if there are any questions relative to tools/

methods. Some of the products manufactured

by Emerson may be used in radioactive

environments. Consequently, prior to starting

any operation in a radioactive environment, the

proper “health physics” procedures should be

consulted and followed, if applicable.

The installation, operation and maintenance

of valves and/or valve products may involve

proximity to fluids at extremely high pressure

and/or temperature. Consequently, every

precaution should be taken to prevent injury

to personnel during the performance of any

procedure. These precautions should consist

of, but are not limited to, ear drum protection,

eye protection, and the use of protective

clothing, (i.e., gloves, etc.) when personnel

are in or around a valve work area. Due to

the various circumstances and conditions in

which these operations may be performed

and the possible hazardous consequences of

each way, Emerson can not possibly evaluate

all conditions that might injure personnel or

equipment. Nevertheless, Emerson does offer

the safety precautions for customer information

only.

It is the responsibility of the purchaser or user

of Emerson valves/equipment to adequately

train all personnel who will be working with

the involved valves/equipment. Further, prior

to working with the involved valves/equipment,

personnel who are to perform such work

should become thoroughly familiar with the

contents of this manual.

YARWAY MODEL 950 HANCOCK FORGED STEEL GATE VALVE

InstallatIon and maIntenance InstructIons

2 SAFETY PRECAUTIONS

• Class 800 valves are shipped with the packing

gland nuts only hand tight. Always tighten

the packing gland nuts before pressurizing

a valve.

• Do not attempt to remove the packing gland

nuts while the valve is under pressure.

• Do not attempt to eliminate bonnet gasket

leakage by tightening the bonnet bolts while

the valve is under pressure.

• The bonnet should not be removed while the

valve is under pressure.

• Do not attempt to remove the thread bushing

while the valve is under pressure.

• All valves equipped with the permanent (fixed)

backseats are capable of being repacked

under pressure. However, due to the inherent

dangers* involved in working on equipment

under internal pressure, it is strongly

recommended that backseats only be used to

prevent this line fluid from escaping through

the stuffing box, until such time as all internal

pressure and/or hazardous fluids can be

removed,and the valve can be repacked under

safe conditions.

• No alteration and/or modification should be

made to any valve, except as sanctioned and/

or authorized by Emerson.

• Any modification of a valve, to accept a gear

operator, motor operator or pneumatic /

hydraulic actuator should be accomplished

using only those designs sanctioned and/or

authorized by Emerson.

• Never install, or attempt to use, any valve that

is not properly identified as to its material and

pressure class.

* The valve may have been modified internally by

other than Emerson personnel, and/or may have

damaged internal parts (e.g., broken, cracked

or severely damaged stem). Such unauthorized

modification, or such possible damage, could cause

a sudden rupture, or pressurization, of the packing

while the packing is being removed or installed, thus

endangering the surrounding equipment and safety

of personnel.

3 INTRODUCTION TO CLASS 800 VALVES

All valves are made to the highest quality

standards and meet or exceed the specification,

code and application requirements for which

they are designed. Although Emerson valves

are among the most ruggedly designed

products in the industry, they are still precision

pieces of equipment and, as such, require

proper care. Adherence to the handling,

storage, installation and maintenance

procedures contained in this manual will

greatly enhance the service life of the valve,

as well as help ensure the safety of personnel.

It is essential that all personnel assigned to

install, operate and/or service valves be trained,

have read and be thoroughly familiar with all

the information contained in this manual, prior

to starting work on the product. In the event

that there are any questions relative to the

instructions contained in this manual, contact

our service center for clarification prior to

proceeding.

4 DESIGN FEATURES AND NOMENCLATURE

The principal design features and parts

nomenclature for the Type 950-4 valves are

provided in Figure 1.

Part

No. Nomenclature

Spare part

classification

1 Thread bushing nut Class 5

2 Marker plate N/A

3 Handwheel Class 3

4 Key Class 3

5 Handwheel washer Class 5

6 Thread bushing washer Class 5

7 Thread bushing Class 2

8 Packing gland nut Class 2

9 Packing glandflange Class 2

10 Packing gland Class 2

11 Stem* Class 1

12 Packing glandbolt Class 2

13 Pin Class 2

14 Packing cartridge Class 1

15 Bonnet bolt Class 3

16 Bonnet Class 5

17 Gasket Class 1

18 Body Class 5

19 Seat facing N/A

20 Wedge* Class 1

21 Seat Class 3

22 Stake lock N/A

FIGURE 1

Type 950-4 and gate valves

* New to stem and wedge design changes, wedge

and stem must be replaced as a unit.

¼ - 4 225

⅜ - 4 225

½ - 4 225

¾ - 4 225

1 4 6 300

1¼ 5 6 400

1½ 5 6 400

2 6 7 500

- 7 8 550

YARWAY MODEL 950 HANCOCK FORGED STEEL GATE VALVE

InstallatIon and maIntenance InstructIons

6 OPERATION

When opening or closing the valve, torques, as

specified in Table 1, should not be exceeded.

If the valve is not tight when properly torqued,

opening the valve and reclosing may free

foreign material trapped on the seats. Do not

use a wrench to close the valve. If the valve will

not shut off tightly, when seating surfaces are

free of foreign material, the valve should be

scheduled for servicing.

7 HANDLING

Care should be exercised when handling all

valves, in order to prevent damage to the

handwheel or stem. Valves should not be

dropped or subjected to sharp impact during

transportation or installation.

ATTENTION

Do not drop or strike valve.

8 STORAGE

Indoor storage of valves is recommended. If

prolonged storage is anticipated, the valves

should be stored in a humidity controlled

storage area. If valves are ordered to a more

stringent cleaning and storage procedure, the

recommendations in that procedure should be

followed.

9 PRE-INSTALLATION

Prior to installation, the following steps should

be taken:

1. Leave end caps in place until ready for

installation, then remove.

2. Inspect both ports for obstruction or foreign

materials. Clean when necessary.

3. Valves are shipped with gland nuts loose.

These nuts must be tightened before putting

the valve in service.

4. If packing is not installed in the valve, refer

to the maintenance instructions (see section

15.D) in this manual for packing installation

directions.

ATTENTION

Tighten gland nuts before placing valve in service.

TABLE 1 - MAXIMUM PERMISSIBLE TORQUE

Valve size

950

Handwheel Dia. - inches Inch-pounds

At least Less than (+ - 0%)

5 OPERATING PRINCIPLES

Type 950-4 valves are basic gate valves with

non-rotating stems. These valves are easily

operated by rotating the handwheel clockwise

to close and counterclockwise to open. Gate

valves are not designed for throttling service.

For long service life with minimum of erosion

of body, seats, and wedge, the valves should be

operated in a full open or closed position. Gate

valves have an integral backseat and when the

valve is operated in the full open position, the

valves should be

2 turn off the backseat.

WARNING

Know nuclear "health physics" procedures, if

applicable, to avoid possible severe personal

injury or death.

CAUTION

Wear necessary protective equipment to preven

possible injury

DANGER

Do not remove packing gland nuts, bonnet or

thread bushing if valve is under pressure, as this

will result in severe personal injury or death.

ATTENTION

Do not alter or modify valve without authorization.

ATTENTION

Do not install or use valve if material and/or

pressure class are not known.

When possible, type 950 gate valves should be

operated fully open, but ½ turn off the backseat.

When a valve is in a partially closed position,

velocity of flow is increased and the possibility

of erosion of the seating surfaces is greater.

ATTENTION

Do not exceed specified torques, or use a wrench

to close valve.

¼ - ¾ 7220815 7221115

1 7220816 7221116

1¼ -1½ 7220817 7221117

2 7220818 7221118

2½ - 3 7220823 7221123

YARWAY MODEL 950 HANCOCK FORGED STEEL GATE VALVE

InstallatIon and maIntenance InstructIons

B. Specific steps

To repack a valve under pressure, when

absolutely dictated by necessity, turn

the handwheel counterclockwise until

the stem makes up on the backseat. If

the original leak has stopped, loosen the

packing gland nuts, but do not remove.

The reason for not removing the gland nuts is

to allow a reasonable amount of time to pass in

order to be certain that the backseat is holding

tight and there is no evidence of leakage or

packing movement. Once assured that the

backseat is holding tight, proceed to remove

the packing gland nuts completely. Wire the

packing gland and packing gland flange to

the handwheel to allow more room to remove

the packing. When removing the old packing,

care should be taken not to damage the stem

or packing chamber wall. When valves are

repacked without disassembly, the packing

illustrated in Figure 2, part numbers for which

are shown in Table 2, must be used.

When inserting new packing rings and bull

rings, stagger the splits in the successive rings

at 90 degree angles. (Again, see Figure 2.)

TABLE 2 - PACKING

Valve size

NPS 950

Packing cart

part no.

Packing set

part no*

Top bull ring

Lower bull ring

Individual split

grafoil rings

FIGURE 2

Packing set individual split rings

* Packing set is supplied in a set of individual split

rings with bull rings.

12 PACKING LEAKAGE

For parts nomenclature, refer to Figure 1

of this manual. When the valve has been

placed in service and has been brought up to

temperature, the packing should be checked

for leakage. Close the valve ½ turn and check

the packing for leakage. If leakage occurs,

adjust the packing gland. To adjust the packing

gland, run the nuts down evenly ½ turn on all

gland bolts and check for leakage. If leakage

continues, turn the nuts down another ½ turn

on all bolts. Turn the handwheel back and forth

½ turn after each adjustment. Again, check for

leakage. If binding of the stem occurs and the

leakage has stopped, loosen the packing nuts

¼ turn. Check the stem for binding and check

for leakage. The object is to tighten the packing

a minimum amount to prevent leakage, while

producing a minimum amount of stem binding.

If leaking through the packing continues and

cannot be completely stopped by tightening

the packing, then the valve should be firmly

backseated to prevent steam damaging the

stem or the bonnet. The valve should then be

scheduled for inspection and repair at shut

down.

13 REPACKING UNDER PRESSURE

A. General information

The bolted bonnet valve design is fitted with

an integral backseat as standard. Although

the backseat provides a means of packing the

gland box under pressure Emerson does not

recognize this as a safe practice. (Again, see

“Safety precautions” Section 2).

DANGER

Do not repack a valve under pressure unless it is

absolutely necessary, as this will result in severe

personal injury or death.

10 INSTALLATION

Type 950-4 Gate valves may be installed with

the stem in any desired position and they

will operate equally well with flow in either

direction.

ATTENTION

Do not ground to bonnet, stem or handwheel

when welding.

11 WELDING

Valves should be opened and backseated prior

to welding. Care should be taken not to ground

to the valve bonnet, stem, or handwheel.

Maintain 359° interpass temperature

requirement when installing stainless

steel valves.

Next, reinstall the packing gland and gland

flange onto the bolts and tighten the nuts

evenly by alternately turning each nut one full

turn. When the nuts are tightened securely,

slowly open the valve slightly and check for

packing leakage. If the packing leaks, tighten

the nuts alternately ½ turn each and check

again. When the leakage stops, operate the

valve open and closed about ½ turn to check

if the stem is binding with the packing.

Should any binding be severe, yet the

packing is not leaking, loosen the gland nuts

approximately ¼ turn each to relieve the stem

binding, checking again for leakage through

the packing.

The valve can now be adjusted to the proper

position to attain the desired flow rate.

YARWAY MODEL 950 HANCOCK FORGED STEEL GATE VALVE

InstallatIon and maIntenance InstructIons

C. Disassembling the bonnet assembly

The bonnet assembly may now be

disassembled. Remove the two packing gland

nuts. Free the packing gland from the packing

chamber.

Remove the stem by rotating the handwheel

clockwise while holding the stem until it

disengages the thread bushing. The stem may

now be forced through the packing chamber.

Remove the packing gland flange and the

packing gland.

Remove the thread bushing nut. Remove

the handwheel, washer and key. The thread

bushing and thread bushing washer can now be

removed. Remove the packing, taking care not

to damage the stuffing box.

15 MAINTENANCE

A. General information

1. The use of a wrench on the handwheel is

not recommended. If the valve will not shut

off tightly when seating surfaces are free

of foreign material, refinishing of seat and

wedge is indicated.

2. Continued leakage through the stem

packing may damage the valve beyond

repair. The packing gland should be

adjusted as soon as leakage is detected

(See section 12).

B. Removing and replacing seat rings

1. General information

Emerson gate valves have renewable seat

rings expanded into the valve body. Should it be

desirable to replace the seat rings remove the

valve from the line and follow the procedure

specified below.

2. Removing the seat rings

Seat rings may be removed with a hardened

steel punch, in a press. (See Figure 3 and

Table 3.) As an alternative, with a heavy

hammer, and with care, they may be removed

with a blunt chisel. The seat ring should be

driven out of socket and then removed through

the bonnet opening in the valve.

3. Installing new seat rings

Seat rings may be installed by the drift method

of expanding the ring. In this process a tool

called a drift is used. (See Figure 4 and Table 4.)

Before placing the seat rings in the valve body,

be sure that the surfaces of the body and the

seat rings are clean and all free of all burrs,

scales and foreign matter. Place the seats

in the body with the narrow section up. They

should have just sufficient clearance to turn

freely in the body.

14 DISASSEMBLY

A. General information

Type 950-4 Gate valves can easily be

disassembled for inspection, maintenance

or repair if the following procedures are

adhered to.

B. Removing the bonnet assembly

Note: do not remove the bonnet bolts if the valve

is under line pressure.

Before beginning disassembly, open the valve

until light contact on the backseat is felt. This

will ensure that the wedge does not become

free of the stem. (refer to Figure 1 for parts

nomenclature.)

Remove the four bonnet bolts using standard

socket wrenches. The bonnet assembly may

then be lifted off.

Remove the bonnet gasket from the body,

taking care not to damage the gasket seating

surface. The wedge may now be removed from

the stem, after turning the handwheel several

times as if closing the valve.

DANGER

Do not remove bonnet bolts if pressure in line, as

this will result in severe personal injury or death.

3. The packing gland flange should be adjusted

an equal amount on each side to ensure

proper compression of the packing and to

avoid contact of the gland or flange with the

stem. If adjustment of the packing gland

does not eliminate leakage, additional

packing should be inserted, or the valve

should be completely repacked with

packing suited to the service.

New packing may shrink when first put in

service and additional packing may be required.

Packing glands on valves used on elevated

temperatures should be adjusted shortly after

being brought up to operating temperature.

ATTENTION

Do not exceed specified torques, or use a wrench

to close valve.

Insert the wedge and stem, and line up the seat

rings with the wedge by using a rocking motion

of the stem/wedge assembly. If necessary, the

seats may be rotated to insure a good fit with

the wedge. When proper alignment is obtained,

the corners of the wedge and the machined

guides will show a uniform clearance on all

four corners.

Tap the end of the stem lightly to seat the

wedge. The wedge seat joint may be further

checked by inserting a light in the bonnet

opening and checking through the port opening.

The valve is now ready for final assembly. Do

not remove seat rings after they have been

properly positioned. Assemble the valve,

complete with packing, then close the valve,

forcing the wedge into a closed position. The

valve is now ready for expanding the seat skirt.

The seat rings are expanded with a drift, a well

lubricated, tapered expanding tool, in a press,

or by a roller type expanding tool in a drill press

or lathe. The drift should be driven in until the

seat is fully expanded and tight against the

body. Reverse the valve and expand the second

seat ring, being careful not to over-expand.

Loosen the wedge to check the work, and if the

seats have been properly expanded, the valve is

ready for test.

ØE

45°

ØB ØA

ØE

45°

ØA

20°

¼ .420 .366 3 ½ 1

.418 .362

⅜ .420 .366 3 ½ 1

.418 .362

½ .495 .454 3

8 1

.493 .450

¾ .620 .495 3½ ¾ 2

.618 .491

1 .930 .727 3

8 1 2

.928 .723

- 1.085 .727 4 1 2

1.080 .723

1 -1¼ 1.310 .547 3

8 1

1.308 .537

1 -1½ 1.310 .547 3

8 1

1.308 .537

2 1.684 .844 7½ 1

4 5½

1.690 .834

- 2.312 .844 7½ 2

2 5½

2.305 .834

¼ - ¾ 7194001 7220815 7221115

1 7194002 7220816 7221116

1¼ -1½ 7194003 7220817 7221117

2 7194004 7220818 7221118

2½ - 3 7194007 7220823 7221123

¼ .431 .302

16 2

16 8

.429 .300

⅜ .495 .365

8 2

16 8

.493 .362

½ .495 .365

8 2

16 8

.493 .363

¾ .620 .490

8 ¾ 2

2 8

.618 .488

1 .932 .740

8 1

16 2

4 8

.930 .738

- 1.085 .930

8 1

16 2

4 8

1.080 .925

1 -1¼ 1.307 1.115

16 1

16 2

2 8¼

1.305 1.113

1 -1½ 1.307 1.115

16 1

16 2

2 8¼

1.305 1.113

2 1.557 1.365

8 1

16 3 8¼

1.555 1.363

- 2.300 1.900

8 2

2 4 9

2.295 1.895

TABLE 3 - PUNCH DIMENSIONS

Valve size

NPS 950 A B C E F

16 x 45°

Chamfer

8 x 45°

Chamfer

16 x 45°

Chamfer

FIGURE 3

Seat removal punch

FIGURE 4

Drift tool

D. Repacking with no pressure

Disassembled valves may be repacked with

a packing set composed of two bull rings and

individual rings of compressed graphite, or with

a packing cartridge of compressed graphite

filament with bull rings, as shown in Figure 5.

Appropriate part numbers for both packing sets

and packing cartridges are shown in Table 5.

Valves of the bolted bonnet design may be

successfully repacked with any good grade of

packing as recommended for the appropriate

service.

Recommended factory replacement packings

are shown in Table 5. Unless otherwise

specified, valves of the bolted bonnet design

are packed by Emerson with a solid graphite

packing cartridge, consisting of compressed

graphite ribbon with split bull rings of braided

graphite. Split ring graphite packing is also

available as service packing.

TABLE 4 - DRIFT TOOL DIMENSIONS

Valve size

NPS 950 A B C E F G

Individual split

graphite intermediate

Solid graphite

intermediate cartridge

Upper bull

ring

TABLE 5 - PACKING AND GASKET PART

NUMBERS

Valve size

NPS 950

Bonnet

gasket part

no.

Packing

cartridge

part no.

Packing

set part

no.

Upper bull

ring

lower bull

ring

lower bull

ring

FIGURE 5

YARWAY MODEL 950 HANCOCK FORGED STEEL GATE VALVE

InstallatIon and maIntenance InstructIons

E. Bonnet gasket replacement

All Hancock Class 800 valves use a propriatary

spiral wound gasket located between the

specifically designed body flange and bonnet

flange to provide the tightest possible joint.

Gasket compression is an important factor in

obtaining a tight joint. The dimensions of these

parts are shown in Figure 6. Replacement

gaskets may be obtained from Emerson.

See Table 5 for part numbers.

NOTES

When a valve has been disassembled for any reason,

the gasket must be replaced to assure reliable

performance of the bonnet joint.

A clean dry surface is necessary for a tight seal.

0.187

0.000

0.005

0.087

0.000

0.005

0.092

0.006

0.000

0.125 0.005

1 4

¼ , ½ ½ - 13 65

16 - 12 100

1¼ ,1½

8 - 11 135

2½ , 3

8 - 9 340

See

note

Bonnet

Body

Gasket

NPS 1 valves and smaller

NPS 1 ¼ valves and larger

125 RMS

FIGURE 6

Body-bonnet gasket seating dimensions

FIGURE 7

Torquing sequence

YARWAY MODEL 950 HANCOCK FORGED STEEL GATE VALVE

InstallatIon and maIntenance InstructIons

16 RE-ASSEMBLY

A. General information

Type 950-4 Gate valves are no more difficult to

reassemble than they are to disassemble.

B. Specific steps

1. Insert the correct number of packing rings

or a packing set into the gland box. Slip

the thread bushing washer over the thread

bushing, then lubricate the I.D. and O.D.

threads of the thread bushing. Insert this

assembly between the yoke arms and into

the top of the bonnet opening.

2. While holding the thread bushing up in

place, slip the handwheel washer over

the thread bushing and insert the key into

the milled slot. Assemble the handwheel

to the thread bushing. Replace marker

plate and tighten the thread bushing nut.

Upset (stake) the nut thread for locking.

Slip the packing gland and packing gland

flange through the yoke arms and align

with the packing chamber. Insert the stem

through the bottom of the yoke. Work

the stem through the packing by rotating

counterclockwise while exerting pressure.

Continue to work until the ACME threads on

the stem engage the ACME threads on the

thread bushing.

3. Slip the stem into the “T” slot of the wedge.

After the ACME threads have engaged,

rotate the handwheel counterclockwise until

the stem makes upon the bonnet backseat.

Apply lubricant to the packing gland bolt

threads. Lift the gland flange and place the

gland flange swing bolts through the flange

holes. Screw the packing gland nuts onto

the packing gland bolts.

4. The bonnet assembly is now ready for

attachment to the body. Install a new gasket

into the body recess, align the wedge to fit

between the seats then install the bonnet

assembly on the body. Lubricate the threads

of the four bonnet bolts and screw the

bolts into the body. Tighten the bolts in the

sequence shown in Figure 7. Use several

increments to obtain the maximum torque

specified in Table 6.

5. If it is necessary to replace seat rings,

proceed in accordance with section 15B.

6. This completes reassembly of the Type

950-4 Gate valve. The valve is now ready

for test.

TABLE 6 - TORQUE TABLE

Valve size

NPS 950

Torque

Ft.Lbs

{+ - 0%}

Problem

Probable cause

Corrective action

Seat leakage Foreign material between seats

and disc.

Open valve to flush material out. (See operation,

section 6.)

Steam cut or damaged wedge Replace wedge (See maintenance, section 15.B)

Valve not fully torqued closed. Add torque (See table 3, section 15)

Packing

leakage

Packing gland loose. Tighten gland bolts (See packing leakage, section 12)

Insufficient packing in box. Add packing (See repacking under pressure, section 13)

Wrong packing for the service

and conditions.

Change packing (See repacking Under pressure,

section 13)

Stem and/or bonnet steam cut. Replace stem and/or bonnet

Body-bonnet

joint leakage

Bonnet bolts loose. Tighten bonnet bolts (See re-assembly, section 16)

Thermal or hydraulic shock. Replace bonnet gasket (See bonnet gasket

replacement, section 15.E)

Corrosion of sealing surface Replace body or bonnet, as required

Steam cut sealing surface Replace body or bonnet, as required

Overpressure Replace bonnet gasket

High operating

torque

Packing gland pulled down too tight Loosen gland nuts (See packing leakage, section 12)

Stem threads not lubricated Lubricate threads (See re-assembly, section 16)

Stem or stem threads bent Replace stem

17 CLASS 800 VALVE TROUBLE SHOOTING

1-1/2"

SA105

CR-13

YARWAY HANCOCK

SIZE:

CLASS:

BODY:

FIG. NO:

800 B16.34LTD 2000 CWP

STEM: DISC:HF SEAT:HF

MADE IN TAIWAN

950

YARWAY MODEL 950 HANCOCK FORGED STEEL GATE VALVE

InstallatIon and maIntenance InstructIons

FIGURE 8

Valve marker plate

19 IDENTIFICATION AND ORDERING

ESSENTIALS

When ordering service parts, please furnish the

following information to ensure receiving the

correct replacement parts:

Identify valve by marker plate information

(see Figure 8):

1. Nominal valve size

2. Complete figure number -including dash

numbers

3. Pressure class

4. Valve type

Example:

NPS 1-½

950W-4

CL. 800

Gate valve

Specify parts required by:

1. Part name

2. Part number (if known)

3. Quantity required

Example:

1. Packing cartridge

2. 7220817

3. Two (2)

Class Part name

Valve size

NPS

Quantity of parts recommended/number

of same size and type valves in service

Need

probability

coverage

Valve type

950-4 950-4-455 950-4-535

1 Stem ¼ - 3 1/10 70

Wedge ¼ - 3 1/10 70

Packing ¼ - 3 1(Individual ring cartridge)/1 70

Gasket ¼ - 3 1/1 70

2 Packing gland ¼ - 3 1/20 85

Thread bushing ¼ - 3 1/20 85

Bonnet bolt ¼ - 2 4/20 - 4/20 85

Bonnet stud ¼ - 2 - 4/20 - 85

Bonnet stud 2½ - 3 4/20 4/20 - 85

Bonnet stud nut ¼ - 3 - 4/20 - 85

18 INVENTORY PHILOSOPHY

It is recommended that a spares inventory

be maintained at the user site. Consult the

Recommended spare parts list (see section20)

to define the parts to be included in the

inventory plan

The basic objectives in formulating a

replacement parts plan are:

• PROMPT AVAILABILITY

• MINIMUM DOWNTIME

• SENSIBLE COST

• SOURCE CONTROL

Guidelines for establishing meaningful

spare parts inventory levels are based on the

frequency of replacement, number of valves in

service and criticality of the service application.

Neither Emerson, Emerson Automation Solutions, nor any of their affiliated entities assumes responsibility for the selection, use or maintenance of any product.

Responsibility for proper selection, use, and maintenance of any product remains solely with the purchaser and end user.

Yarway is a mark owned by one of the companies in the Emerson Automation Solutions business unit of Emerson Electric Co. Emerson Automation Solutions, Emerson

andthe Emerson logo are trademarks and service marks of Emerson Electric Co. All other marks are the property of their respective owners.

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. All sales are governed by

our terms and conditions, which are available upon request. We reserve the right to modify or improve the designs or specifications of such products at any time without

notice.

Emerson.com/FinalControl

20 RECOMMENDED SPARE PARTS - TYPE 950-4 GATE VALVES

PARTS CLASSIFICATION

Part

classification

Replacement

frequency

Predicted

Availability %

Class 1 Most frequent 70

Class 2 Less frequent but