Jordan Valve Mark EZ Series Globe Style Control Valve User Manual

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Packing Maintenance

This section covers PTFE V-ring packing as used in

plain and extension bonnets. Unless otherwise indi-

cated, key numbers refer to figure 2 for PTFE V-ring

packing.

For spring-loaded single PTFE V-ring packing, the

spring (key 8, figure 2) maintains a sealing force on

the packing. If leakage is noted around the packing

follower (key 13, figure 2), check to be sure the

shoulder on the packing follower is touching the

bonnet. If the shoulder is not touching the bonnet,

tighten the packing flange nuts (key 5, figure 10),

until the shoulder is against the bonnet. If leakage

cannot be stopped in this manner, proceed to the

replacing packing procedure.

If there is unacceptable packing leakage with other

than spring-loaded packing, first try to limit the

leakage and establish a stem seal by tightening the

packing flange nuts.

If the packing is relatively new and tight on the stem,

and if tightening the packing flange nuts does not stop

the leakage, the valve stem may be worn or nicked

so that a seal cannot be made. The surface finish of

a valve stem is critical for making a good packing

seal. If the leakage comes from the outside diameter

of the packing, the leakage may be caused by nicks

or scratches around the packing box wall. If perform-

ing any of the following procedures, inspect the valve

stem and packing box wall for nicks and scratches.

Replacing Packing

The following section covers packing replacement as

used in plain and extension bonnets. Refer to figure 2

for PTFE V-ring packing.

1. Isolate the control valve from the line pressure and

release pressure from both sides of the valve body.

Drain the process media from both sides of the

valve. If using a power actuator, also shut off all

pressure lines to the power actuator, and release all

pressure from the actuator. Use lock-out procedures

to be sure that the above measures stay in effect while

you work on the equipment. Observe the warning at

the start of the Maintenance section.

2. Disconnect the operating lines from the actuator

and any leak-off piping from the bonnet. Disconnect

the stem connector and then remove the actuator

from the valve by unscrewing the yoke locknut (key

15, figure 10).

Loosen the bonnet by following the instructions
in the next step to avoid personal injury or prop-
erty damage. Do not remove a stuck bonnet by
pulling on it with equipment that can stretch or
store energy in any other manner. The sudden
release of stored energy can cause uncontrolled
movement of the bonnet.
The following step also provides additional assur-
ance that the valve body fluid pressure has been
relieved.

3. Hex nuts (key 16, figure 11) attach the bonnet to

the valve. Loosen these nuts or cap screws approxi-

mately 3 mm (1/8 inch). Then loosen the body-to-

bonnet gasketed joint by either rocking the bonnet

or prying between the bonnet and valve body. Work

the prying tool around the bonnet until the bonnet

loosens.

4. Loosen the packing flange nuts (key 5, figure 10)

so that the packing is not tight on the valve stem.

Remove any travel indicator parts and stem locknuts

from the valve stem threads.

When lifting the bonnet, temporarily install a valve
stem locknut on the valve stem. Avoid damaging
the seating surface caused by the valve plug and
stem assembly dropping from the bonnet after be-
ing lifted part way out.
This locknut will prevent the valve plug and stem
assembly from dropping out of the bonnet.

5. Completely remove the cap screws (not shown)

or hex nuts (key 16, figure 11) that bolt the bonnet

and valve body together and carefully lift the bonnet

off.

6. Remove the locknut and separate the valve plug

and stem from the bonnet. Set the parts on a

protective surface to prevent damage to gasket or

seating surfaces.

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