Emerson Fisher YD & YS Manuál s instrukcemi stáhnout pdf (Strana 7)

Instruction Manual

D100425X012

YD and YS Valves

October 2014

1. Remove the actuator and bonnet according to steps 1 through 4 of the Disassembly procedure in the Maintenance

sectiononpage7.

2. With the stem and valve plug assembly removed from the bonnet, remove the packing nuts (key 5), packing flange

(key 3), wiper ring (key 12), and packing follower (key 13) from the bonnet. The old packing can then be pulled out

with a packing hook (take care to avoid scratching the packing box wall) or pushed out using a rod inserted through

the bottom of the bonnet.

3. Clean the packing box and all metal parts.

4. Complete maintenance necessary on other parts and install the bonnet on the valve as indicated in the Assembly

section (starting on page 12).

5. Install the new packing and associated parts in the sequence shown in figures 3, 4, 5, 6, and 7. Be careful not to

damage the packing during installation.

6. Replace the packing flange and packing flange nuts.

For spring-loaded PTFE V-ring packing, tighten the packing flange nuts until the shoulder on the packing follower

contacts the bonnet.

For graphite packing, tighten the packing flange nuts to the maximum recommended torque shown in table 3. Then,

loosen the packing flange nuts, and retighten them to the rec ommended minimumtorqueshownintable3.

For other packing types, t ighten the packing flange nuts alternately in small equal increments until one of the nuts

reaches the minimum recommended torque shown in table 3. Then, tighten the remaining flange nut until the

packing flange is level and at a 90-degree angle to the valve stem.

For ENVIRO-SEAL or HIGH-SEAL live-loaded packing, refer to the note at the beginning of the Packing Maintenance

section.

7. Mount the actuator on the bonnet and make up the stem connection according to t he procedure given in the

appropriate actuator instruction manual.

Trim Maintenance

WARNING

Observe the warning at the start of the Maintenance section.

CAUTION

To avoid damaging parts, do not grip the bellows shroud or other parts of the stem/bellows assembly. Grip only the flat

areas on the stem where it extends out of the top of the bellows shroud.

Key numbers in the following procedures are shown in figure 10 for standard YD, in figure 11 for high-temperature YD,

and in figure 9 for YS, except where indicated.

Disassembly

1. Isolatethecontrolvalvefromthelinepressure,releasepressure from both sides of the valve, and drain the process

mediafrombothsidesofthevalve.Removeactuatorsupplypressure,anduselock-outprocedurestobesurethat

the above measures stay in effect while you work on the equipment.

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Emerson Fisher YD & YS Manuál s instrukcemi Strana 7