38
OIC 12en Edition 08/2016
Operating Instructions
Tightening torques
Appendix
Tightening torques
Tab. 2 Tightening torques
Contents of the EC Declaration of Conformity
The screw pumps described in these operating instructions are machinery in the sense of the Directive
2006/42/EC. The original of the EC Declaration of Conformity is enclosed with the machinery at delivery.
The machinery fulfils all the relevant provisions of the following directives:
Tab. 3 Directives observed
Tightening torque [Nm] for screws with metric t head contact surfaces
With thread measured
in inches
Threa
d
+ wedge lock
washers
Stainless steel
screws
A2 and A4
Screw plugs with
elastomer seal
5.6
8.8
10.9
8.8 +
Alu*
8.8
Rust-
proof
A4-70
Pro
perty class
7
0
Pro
perty class
8
0
Threa
d
Galv
aniz
ed +
St
ainless
st
eel
M 3
0.6
1.5
–
1.2
1.5
1.1
–
–
G 1/8"
13
M 4
1.4
2.9
4.1
2.3
3
2
–
–
G 1/4"
30
M 5
2.7
6.0
8.0
4.8
6.0
3.9
3.5
4.7
G 3/8"
60
M 6
4.7
9.5
14
7.6
10.3
6.9
6
8
G 1/2"
80
M 8
11.3
23.1
34
18.4
25
17
16
22
G 3/4"
120
M 10
23
46
68
36.8
47
33
32
43
G 1"
200
M 12
39
80
117
64
84
56
56
75
G 1 1/4"
400
M 14
62
127
186
101
133
89
–
–
G 1 1/2"
450
M 16
96
194
285
155
204
136
135
180
* Reduced tightening
torque when screwing
into aluminium
M 18
133
280
390
224
284
191
–
–
M 20
187
392
558
313
399
267
280
370
M 24
322
675
960
540
687
460
455
605
Number
Name
Remark
2006/42/EC
Machinery Directive
–
2014/68/EU
Pressure Equipment Directive
–
2014/30/EU
Directive on Electromagnetic
Compatibility
Only for machinery with electrical
components
2014/35/EU
Low Voltage Directive
Only for machinery with electrical
components
2014/34/EU
Directive on Use in Potentially Explosive
Areas (ATEX)
Only for machinery in ATEX version