Installation, Operation and Maintenance Manual
MAN 689 Rev. 6
June 2021
Installation
Actuator model
Ø d
1
Ø d
2
Ø d
3
Ø d
4
N
h
1
h
2
H max Ø d
5
W
K
0.3
240
93
165
M20
4
5
17
127
70
12
75.6
0.9
310
112
254
M16
8
5
19
150
86
14
93.6
1.5
360
144
298
M20
8
6
19
190
112
18
119.0
3
430
195
356
M30
8
9
23
200
157
25
167.8
6
520
250
406
M36
8
14
29
260
200
28
212.8
Dimensions in millimeters
Table 2.
SCN 6200
5
Section 2: Installation
2.3
Assembling the Actuator onto the Valve
2.3.1
Types of Assembly
For coupling to the valve, the housing is provided with a flange with threaded holes
according to Biffi standard tables (SCN6200; SCN6200-1; SCN6201; SCN6201-1).
The number, dimensions and diameter of the holes are made in accordance with ISO 5211,
but for actuator models 0.3 to 6 the holes are drilled on the centerline in order to allow an
easier assembly of an intermediate flange, when required. This intermediate flange
(or spool-piece) can be supplied when the valve flange cannot directly match the actuator
flange in its “standard” configuration. For the biggest actuator models, the actuator flange
can be machined in accordance with the valve flange dimensions.
The yoke has bored with keyways for coupling to the valve stem, the dimensions of which
are according to Biffi standard tables SCN6200* and SCN6201*.
Figure 2
Coupling Dimensions - Models 0.3 to 6
45
°
K
+0.4
0
Top view of the scotch yoke mechanism
(actuator shown in closed position)
N
.4 h
ole
s flan
ge
N
.8 h
ole
s flan
ge
N. THREADED HOLES
PCD, number and size
according to ISO 5211
(but the holes are on centerline
instead of straddle the centerline)
Flow line
Drive sleeve
H m
ax
0
h
1
+0.5
0
Ø
d
2
+0.1
Ø
d
3
±0.2
Ø
d
1
max
Ø
d
4
h
2
D10
W
+0.1
Ø
d
5
+0.2
