Flowserve BX 150 - Manual (Page 5)

37-5
Disassembling the Body
To disassemble the Valdisk 150 body, refer to Figures
1 and 3 and proceed as follows:
1. Lay the valve body on a flat surface with the seat
surface up. Carefully insert a flat screwdriver into
the groove behind the seat retainer and pry the
retainer out of the body. The seat insert will now
easily lift out of the body.
2. Turn the body over so its backside is up and mark
the location of the thin end of the taper pin on the
disc. (This mark will be used during reassembly.)
Grind off the tackweld holding the taper pin in place.
Drive the taper pin out of its slot using a punch and
hammer.
3. Place the valve body into a vise with the shaft point-
ing up. Use brass jaws or wood blocks to prevent
damage to the body surfaces.
4. Remove the two packing box nuts and gland flange
from off the shaft.
5. Pull the shaft out of the body, noting that the disc
may fall out of body. Use caution to prevent it from
striking any hard objects or personnel. Next, re-
move the packing follower, packing set and packing
retainer.
6. The disc can now be removed from the body, fol-
lowed by the thrust and shaft bearings.
Reassembling the Body
To reassemble the Valdisk 150 body sub-assembly,
refer to Figures 1, 2, and 3 and proceed as follows:
1. Clean or replace all parts. The O-ring and packing
set should be replaced each time the valve is disas-
sembled.
2. Check the disc seating surface to make sure it is
smooth and free of excessive wear, scoring and
scratches.
CAUTION: Damaged or dirty seat surfaces can
cause excessive seat wear and high torque re-
quirements. Damaged discs should be re-
placed.
3. Inspect the shaft for scratches or galled surfaces.
For maximum performance, Valdisk 150 shafts are
machined to a very smooth finish. If damage exists,
replace the shaft or contact the factory representative.
NOTE: Disc and shaft are interchangeable. Re-
placing the disc does not require replacing the shaft
and vice versa.
4. Place the valve body in a vise with shaft bore point-
ing up. Brass jaws or wood blocks are recom-
mended to prevent damage to the valve surfaces
while being held in the vise.
5. Place one shaft bearing into the lower bearing bore,
followed by a thrust bearing.
6. Place the disc into the body from the backside with
the taper pin slot on top. Do not dislodge the thrust
bearing.
7. Insert the second thrust bearing between the disc
and the valve body. Align both bearings with the disc.
8. Insert the shaft into the body with the taper pin slot
end first. Slowly insert it through the body, upper
thrust bearing, disc, lower thrust bearing and into
the shaft bearing.
9. Insert a new taper pin into the slot in the back of the
disc and in the shaft. Refer to the mark on the disc
made during disassembly and make sure the pin
does not go beyond it. Be certain the pin is flat
against the disc. Set in place with a punch and
hammer.
10. Place the remaining shaft bearings* over the shaft
and into the bearing bore. (*Refer to the valve’s bill
of materials for the number of shaft bearings re-
quired.) Next, place the packing retainer, followed
by the packing set into the packing bore. (See Fig-
ure 2. Teflon packing chevrons point away from the
disc.) Be careful to not damage the packing rings
while inserting them over the shaft.
11. The packing follower is next inserted into the pack-
ing bore with machined lip end up.
12. If the packing box studs were removed, re-install
them using anti-seize lubricant. Tighten until they
bottom out. Place a washer over each stud and se-
cure in place with a jam nut tightened until snug
(valve sizes 1 thru 6-inch).
13. Place the gland flange over the shaft and onto the
studs being certain the rocker knob is facing toward
the disc. Place the packing box nuts onto the pack-
ing box studs and tighten finger tight plus
1 /
2
to one
full turn with Teflon packing. (Rope packing should
be torqued to 14 foot-pounds or 19 newton-meters.)
14. Install the seat assembly into the valve body by first
inserting seat gasket into outer seat retainer groove.
Next, remove the body from the vise and lay it on a
flat surface with the seat side up. Proceed as fol-
lows.
Soft or metal seat design - Lay the seat insert into
the valve body. Next, insert the seat retainer into the
body seat counter bore. Use a rubber mallet or
press to press the seat retainer into the body.
Fire-safe seat design - Place one Grafoil gasket
into the retainer ring groove. Place two additional
Grafoil gaskets on either side of the seat insert.
Place the metal seat on top of the seat/gasket as-
sembly and then place the entire assembly into the
retainer ring in the body. Next, insert the seat re-
tainer into the body seat counter bore. Use a rubber
mallet or press to press the seat retainer into the
body.