INSTALLATION
Series 642
18/113
Edition 2017-11-24
605593EC
4.3
Tightening torque
4.3.1
Mounting of CF-F flanges
Tightening torques for CF-F flange connections depends on the type of seal which is used. Follow
recommendations of seal manufacturer.
Tighten mounting screws of the flanges uniformly in crosswise order. Observe the maximum torque
levels in the following tables.
4.3.2
Mounting with centering rings
DN
max. torque
(Nm)
max. torque
(lbs . ft)
Max. hole depth [d]
(mm)
mm
inch
ISO-F
JIS
ASA-LP
ISO-F
JIS
ASA-LP
ISO-F
JIS
ASA-LP
63
2 1/2
8 – 10
8 – 10
8 – 10
6 – 8
6 – 8
6 – 8
13
13
15
80
3
8 – 10
8 – 10
8 – 10
6 – 8
6 – 8
6 – 8
13
13
15
100
4
8 – 10
8 – 10
8 – 10
6 – 8
6 – 8
6 – 8
13
13
15
160
6
13 – 15 13 – 15
20 - 30
9 - 11
9 - 11
15 – 22
14
14
15
200
8
13 – 15 13 – 15
20 - 30
9 - 11
9 - 11
15 – 22
16
16
20
250
10
17 – 20 17 – 20 40 – 60
13 – 15
13–15
30 – 44
16
16
20
320
12
17 - 20
17 – 20
40 - 60
13 – 15
13–15
30 - 44
16
16
20
350
12
17 - 20
17 – 20
40 - 60
13 – 15
13–15
30 - 44
16
16
20
400
16
17 – 20 30 – 35 55 – 80
13 – 15 22 – 26 41 – 59
25
25
NA
The torque values below are dependent on many factors, such as materials involved,
surface quality, surface treatment, and lubrication.
The torques below are valid if immersion depth of the mounting screws is at least
once the thread diameter (min. 1d), and the friction coefficient of the screw-flange
connection (
µ
total
= (
µ
screw thread-helicoil
+
µ
under screw head
)/2) is bigger than 0.12. Lower
friction coefficients may damage the valve, as the resulting preload force gets too
high. Therefore for other friction coefficients the torque needs to be adapted. Please
review design guidelines for Helicoil-Screw connections and make sure that screws in
use are capable to withstand applied torques, are appropriate for the application and
are not too long. Too long screws may damage the valve, the immersion depth should
not exceed (hole depth – 1 mm).
Refer to «Spare parts / Accessories» for centering rings ordering numbers.
