Tightening Torques For Screwed Connections; Normal Screwed Connections; Special Screwed Connections - Bitzer HS.8551 Instructions De Service

10 Tightening torques for screwed connections

Mind when mounting or replacing parts:
• Clean threads carefully.
• Gaskets:
– Use new gaskets only!
– Do not oil gaskets with metallic support.
– Flat gaskets may be moistened slightly with oil.
• Wrap plugs with sealing tape or coat them with liquid
sealing agent.
• Admissible screwing methods:
– Tighten with calibrated torque spanner to indic-
ated torque.
– Tighten with pneumatic impact wrench and
retighten with calibrated torque spanner to indic-
ated torque.
– Tighten with electronically controlled angled
wrench to indicated torque.
• Tolerance range of tightening torques: ±6% of nom-
inal value
• Tighten flange connections crosswise and in at least
2 steps (50/100%). Alternatively, they may be
tightened in one step with a multi spindle tool.

10.1 Normal screwed connections

Size
M5
M6
M8
M10
M12
M16
M20
M20 with CS.105
Case A: Screws without flat gasket, property class 8.8
or 10.9
Case B: Screws with flat gasket or gasket with metallic
support, property class 10.9

10.2 Special screwed connections

Sealing plugs without gasket
Size Brass
1/8-27 NPTF 35 .. 40 Nm
SB-110-3
Case A Case B
7 Nm
9 Nm 16 Nm
23 Nm 40 Nm
42 Nm 80 Nm
80 Nm 125 Nm
150 Nm 220 Nm
220 Nm 220 Nm
400 Nm
Steel
15 .. 20 Nm
Size Brass
1/4-18 NPTF 50 .. 55 Nm
3/8-18 NPTF 85 .. 90 Nm
1/2-14 NPTF 95 .. 100 Nm
3/4-14 NPTF 120 .. 125 Nm
Sealing screws or plugs with aluminium gasket
Size
M10
M18 x 1,5
M20 x 1,5
M22 x 1,5
M26 x 1,5
M30 x 1,5
M48 x 1,5
G1/4
G1 1/4
Sealing screws or plugs with O-ring
Size
1 1/8-18 UNEF
M22 x 1,5
M52 x 1,5
Sealing nuts with O-ring
Thread
3/4-16 UNF
1-14 UNS
1 1/4-12 UNF
1 3/4-12 UN
2 1/4-12 UN
These sealing nuts are normally used for Rotalock
screwed joints.
AF: width across flats in mm
Screws for shut-off valves and counter flanges
Size
M10
M12
M16
M18
M20
M24
Steel
30 .. 35 Nm
50 .. 55 Nm
60 .. 65 Nm
80 .. 85 Nm
30 Nm
60 Nm
70 Nm
80 Nm
110 Nm
120 Nm
300 Nm
40 Nm
180 Nm
50 Nm
40 Nm
100 Nm
AF
22 50 Nm
30 85 Nm
36 105 Nm
50 150 Nm
65 180 Nm
Case C Case D
50 Nm
36 Nm 100 Nm
98 Nm 150 Nm
136 Nm 200 Nm
175 Nm 200 Nm
320 Nm
25