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3 of 4
Because of the oval form of the drilled hole, low force should
be used to fi x the ring in its place.
Following all V-rings have to be placed one
by one over the
shaft. At this point, all the hexagonal nuts and bolts can be
tighten to their respective torque values (shown bellow).
Now the disks springs ( 8 ) can be fed onto the upper packing
ring ( 5 ) and the stuffi ng box ( 6 ) must be prepared by plac-
ing the bushing ( 7 ) into its bedding.
When this is complete, the stuffi ng box ( 6 ) can now be
placed over the ball stem ( 3 ), being careful that the spring
washers ( 8 ) are central.
Now the stuffi ng box ( 6 ) with the bushing ( 7 ) can be
screwed on to the valve body using the socket head screws
( 9 ) which should also be equally and tightly fastened in case
of the later installation of an actuator.
If required, it is also possible to attach a hand lever.
3.3 Mounting Instructions for Model B
Generally, the mounting instructions are identical to Model A,
except that the ball ( 3a ) and the stem ( 12 ) are two separate
items.
According to this difference, fi rst the shaft ( 12 ) has to be
placed in the basic body ( 1 ) by moving it through the drilled
hole, than the ball ( 3 ) can be fed into the body if the dihe-
dron of the shaft and the groove of the ball fi t into one an-
other.
Now, the rest of the assembling can take place as of Model A.
The assembly of the valve is now completed.
3.4 Tightening torques to connect the body sections
On connecting the body sections together, the sequence for
securing bolts and the tightening torques for each nominal
size must be strictly observed.
Nominal size
Connection
Tightening torque
DN 15
1 bis 4
25 Nm
DN 25
1 bis 6
30 Nm
DN 40
1 bis 7
30 Nm
DN 50
1 bis 7
30 Nm
DN 80
1 bis 13
40 Nm
DN 100
1 bis 14
40 Nm
Table 2 - Tightening torque
3. Assembly of the ball valve
3.1 Preparation for the assembly
In order to assemble the ball valve, all the parts must be pre-
pared, i.e. the parts are carefully cleaned and placed on a soft
surface (rubber mat or similar).
Please, pay attention! Plastic parts are nearly always soft and
very sensitive, and particularly the sealing surfaces should
not be damaged.
Caution:
In order to prevent a cold welding of the
screws in the bodies, a high-performance grease
paste is employed during manufacturing
(e.g. Gleitmo 805. from Fuchs).
For valves employed in oxygen environments, this agent may
not be used. For grease-free valves, especially when em-
ployed in an oxygen environment, a suitable lubricant is to be
chosen.
Note:
The position and arrangement of the individu-
al parts shown in the detail drawing (Fig. 3) are to be
observed during assembly.
The Ball valve from Series 20b is generally subdivided
into two different types :
• Type
A:
one-peace ball and stem
• Type
B:
fl oating ball
As both models are identical in dimension, they can both be
updated or modifi ed at a later point of time.
3.2 Assembling Instructions for Type A
First, the basic body ( 1 ) of the valve has to be placed on its
face on the soft surface.
The seatring ( 4a ) should now be fed into the body ( 1 ).
Now the one-piece ball and shaft ( 3 ) should be fed slant-
wise through the stem drilling hole in the basic body ( 1 ).
Note:
To have an unproblematic assembling take
care that the fl ow direction of ball and shaft are in
one direction.
Notice that at DN 100 / 4” the chamfer of the stem
shows at assembling to the inner side of the body.
Now the lateral body ( 2 ) should be fi tted with the Seatring
( 4b ) and can now be placed into the basic body ( 1 ) using
the hexagon nuts ( 11 ) and bolts ( 10 ) screwed hand tight
together.
Now, using a special tool, (tube, outside diameter less the
diameter of the PTFE-V-ring packing but greater than the
stem diameter), the ball shaft gets centred in the basic body
through fedding the bottom ring of the PTFE-V-ring packing
( 5 ) into its drilled hole.
