Jordan Valve Mark DBAQ Series Angle Style Control Valve - Manual (Page 6)

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Disassembly
1. Remove the actuator from the bonnet. Refer to
steps 1 thru 5 of Replacing Packing procedure.
Observe all warnings and cautions.
NOTE: Avoid damaging gasket sealing surfaces. The
surface finish of the valve stem is critical for ensur-
ing a tight seal. The seating of the seat ring and valve
plug are critical for tight shutoff. Replace accordingly
should an inspection show damage.
2. Carefully lift the valve plug and stem assembly,
cage, seat ring and seat ring gasket out of the
valve body. If the valve plug is being re used,
take care to protect the valve plug stem
and valve plug seating surface from scratches
or damage.
3. Inspect all components for wear or damage that
would prevent proper operation of the valve. Re-
place or repair trim parts accordingly. Refer to
Lapping Metal Seats or Trim Replacement as
required.
Lapping Metal Seats
With metal to metal seating in any valve, a small amount
of leakage can be expected. If the leakage becomes ex-
cessive, it is possible to improve shutoff by seat lapping
of the valve plug and seat ring.
Deep nicks may be machined, rather than ground out.
Apply a good quality lapping compound mixture of 280
to 600 grit to the bottom of the valve plug.
Secure the seat ring using a vise, and hold the cage
against the seat ring to properly align the valve plug and
seat ring while grinding.
Once completed, clean the seating surfaces thoroughly
and test for shutoff. Repeat the lapping process if leak-
age is still excessive.
Assembly
Upon completion of trim maintenance or replacement,
reassemble the valve body using the following proce-
dure. Ensure all gasketed surfaces have been thorough-
ly cleaned.
1. Install the seat ring gasket (key 6) and the seat
ring (key 11) into the valve body.
2. For standard cage installation, align two of the
holes in the cage with the centerline of the valve
body.
3. Install the valve plug and stem assembly (key
4) into the cage. Ensure the m-flat valve
plug orientation is as shown in Figure 2
when replacing the bonnet.
4. Install the bonnet gasket (key 5) and bonnet
(key 2) over the valve stem and onto the body.
5. Lubricate the bolting, unless pre lubricated bolt
nuts are being used. Replace the hex nuts
finger tight. Torque the nuts using proper bolting
procedures in a crisscross pattern to no
more than 1/4 of the nominal torque
value specified in Table 4. After all nuts
have been initially torque, increase the torque by
1/4 of the specified nominal torque using
proper bolting procedures again. Repeat the
process until all nuts are tightened to the
specified nominal value. Apply final torque once
again, should any nut still turn, repeat the torque
process on all nuts.
6. Install new packing box parts using steps 11
thru 13 of the replacing packing procedure.
NOTE: Should minor adjustments be required, re
clamp the actuator and valve stems together. Do not
screw the valve stem in or out of the stem connector
as this may change the orientation of the valve plug
shown in Figure 2.
7. Mount the actuator using correct procedures
referenced in the appropriate actuator manual.
Check for packing leakage when putting
the valve into service. Re-torque packing flange
nuts as required.
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