Jordan Valve Mark D & DA Series Globe & Angle Control Valve User Manual

Page 5

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Trim Maintenance

Disassembly

Remove the actuator and the bonnet as de-

scribed in steps 1 through 3 of the “Replacing

Packing” procedure.

Warning

The seating surfaces and surface finish of

the seat ring (Key 8), stem (packing seal) and

plug (Key 19) are critical for tight shutoff.

Protect these parts from damage if you plan

to re-use them in the valve.

Remove the plug/stem assembly (Key 19) and

the packing parts from the bonnet.

If you re-use the valve plug, protect the valve

plug seating surface and the stem threads to

prevent damage.

Remove the packing parts as described in the

“Packing Maintenance” procedure.

Use a socket wrench to remove the seat ring

(Key 8).

Remove the seat ring (Key 8) and seat ring

gasket (Key 9) from the valve body.

Inspect parts for damage or wear that would

prevent proper operation of the valve body.

Clean the gasket surfaces.

Replace trim parts as necessary or use the

“Lapping Metal Seats” procedure.

Lapping Metal Seats

In any valve body with metal-to-metal seating, a certain

amount of leakage should be expected. However, if

the leakage becomes excessive, lapping can enhance

the condition of the seating surfaces of the plug and

seat ring. Deep nicks in the seating surfaces should be

removed by machining rather than lapping.

There are many lapping compounds available commer-

cially. Be sure to use one of high quality.

Apply the lapping compound to the bottom of the valve

plug. Partially assemble the valve so the seat ring and

valve plug are in place and the bonnet (with bushing

installed) is screwed hand-tight into the body.

Make a simple handle from a piece of metal attached to

the plug stem with nuts. Rotate the handle in opposite

directions with light downward pressure to lap the seat.

Once lapping is complete, remove the bonnet and plug/

stem assembly as a unit, and clean the seating surfaces,

reassemble, and then test for shutoff. If leakage is still

excessive, repeat the lapping process.

Assembly

Thoroughly clean the valve body gasket sur-

faces, seat ring and bonnet threads.

Apply Never-Seez Nickel lubricant or equivalent

to the threads of the seat ring (Key 8), bonnet

(Key 6), and their mating threads in the body.

Put the seat ring gasket (Key 9) into the body.

Screw the seat ring into the body. Use

a socket wrench to tighten the seat ring to the

torque values shown in Table 3.

Clean the bonnet gasket-seating surface, and

install a new bonnet gasket (Key 17).

If you had not removed the plug/stem assembly

and packing from the bonnet, then install the

bonnet (Key 6) and plug/stem assembly (Key

19) as a unit, into the valve body. To prevent

galling ensure the seating surface of the

plug does not contact the seating surface of the

seat ring. Thread the bonnet tightly into

the valve body; see torque values in Table 2.

If you chose to remove the plug/stem assembly

and packing from the bonnet, then remove any

protective covering from the plug/stem

assembly (Key 19) and carefully install it

into the valve body.

Slide the bonnet (Key 6) over the stem and

thread it tightly into the valve body.

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