Flowserve Valtek MaxFlo 3 - Manual (Page 6)

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User instructions - MaxFlo 3 - VLENIM0052-02 02.07
6
6 VALVE DISASSEMBLY
WARNING: To carry out this operation, it is essential to
disconnect the valve from the pipework. Depressurize
line to atmospheric pressure and drain all fluids before
working on the valve. Failure to do so can cause serious
injury. Remove the valve from the pipeline.
Refer to figure to find parts according to the item num-
bers.
6. Remove the actuator from the body by separating the ac-
tuator at the yoke. Refer to the installation, operation and
maintenance manual for the corresponding actuator.
6. Remove the four bonnet nuts (item 4).
6.3 Remove the packing nuts and gland flange (item 80).
6.4 Carefully pull the shaft (item 5) out of the body. The
bonnet, thrust bearing, packing stop and packing will all
slide out of the body bore as an assembly.
NOTE: At this point in the disassembly operation, the plug
is inside the valve body and is only supported by the end
post. When removing the end post, support the plug so it
does not drop into the bottom of the valve body.
6.5 Remove the end post nuts (item 9) and carefully re-
move the end post (item ) from the body.
6.6 Remove the plug from the body. See figure a.
6.7 Loosen the packing-box nuts (item 7) and remove the
shaft from the bonnet by sliding it out slowly. The thrust
bearing (item 46) and the shaft stop spacer (item 47, only
for sizes 0 to ”) can now be removed from the shaft.
6.8 Remove the packing follower (item 87) as well as the pack-
ing (item 88), spacers (item 93) and the packing stop (item
99).
6.9 Remove the bonnet gasket (item 58) and end post gas-
ket (item 6). Clean all bearing and seal surfaces.
6.0 Remove the shaft bearing (item 83) from the valve body.
Use a suitable dowel to push the bearing out if neces-
sary. Be careful not to damage the bearing.
6. Unscrew the seat (item 30) using the appropriate tool
(see Table IV) and remove the seat (item 0) as well as
the adjustment shims (item 3).
7 BODY REASSEMBLY
NOTE: Lubricate all threads, bearings and the shaft
shoulder with a boron nitride paste (Molydal NB1200)
or a nickel anti-seize lubricant (Permatex 77164 or
equivalent). Place the valve body in a vice and clamp
securely in a vertical position.
7. Always use new packing and gaskets when reassem-
bling a valve.
7. Make sure that the shaft, bonnet bore and gasket sur-
faces in the body have been thoroughly cleaned (these
are sealing surfaces and it is imprtant to remove any
contamination before reassembly).
7.3 Make sure that all bearing surfaces have been cleaned.
7.4 Install all end post (item 5) and bonnet (item 08)
studs.
7.5 Insert the plug in the body as shown in figure b.
NOTE: The end post bearing (item 84) is pressed into
the plug.
7.6 Place the end post gasket (item 6) on the end post
(item ). Insert the end post into the small flanged
port in the end of the body. As the end post is inserted,
locate the plug (item 50) so the end post will insert into
the end post bearing located in the plug.
NOTE: For valves 3’’ and larger, insert the end post
with the milled faces parallel to the flanges of the valve
body.
7.7 Tighten the end post nuts to finger tight.
7.8 Insert the shaft bearing (item 83) into the body until the
shoulder on the bearing contacts the step in the valve
body. The bearing will protrude slightly into the body gal-
lery area.
7.9 Place the thrust bearing onto the shaft. Slide it up
to the thrust runner. The shaft thrust bearing will
surround the thrust runner.
NOTE: for sizes 10” and 12”, an end spacer (item 47) is
placed above the thrust bearing.
Figure 2a: Plug Removal Figure 2b: Plug Installation
Table II: Nut tightening torques for bonnet and post
Stud Size A193-B7 A193-B8 cl2 A453-Gr660 (Nace)
M8 ft-lb / 6 Nm 7.5 ft-lb /0 Nm 0.5 ft-lb /4 Nm
M 43.5 ft-lb / 59 Nm 7.5 ft-lb /37 Nm 30.5 ft-lb /4 Nm
M6 6.5 ft-lb / 85 Nm 39 ft-lb /53 Nm 43.5 ft-lb /59 Nm
STOP!