Technical data

32
Compressed Air Applications Manual | Flange joints/screwed connections
Flange joints with O-rings do not require
any great tightening torque. It is rec-
ommended to use a torque wrench to
avoided overtightening of the bolts.
Guide values for tightening the bolts of
flange joints with O-rings:
Flange joints/screwed connections
Connection:
plastic-to-plastic
Flange joints or O-ring sealed screwed
connections are generally used for the
detachable connection of plastic pipes
with each other and for the transition
from plastic pipes to metal pipes or metal
devices (valves, pumps).
• Screwed connections up to d 63
• Flange joints up to d 110
Connection:
Plastic-to-metal
• Flange joints are normally chosen for
the transition from plastic to metal
because the sealing surfaces of the
metal flanges are usually grooved.
• The bolts of flange joints with flange
seals must be tightened with a torque
Outside pipe diameter mm 16 20 25 32 40 50 63 75 90 110
Torque Nm 3 3 4 5 10 12 15 18 20 22
Bolts, nuts, washers,
standard type
Always use washers
wrench in order to avoid damage to the
flange or flange sleeve. The guide values
for the necessary torques in relation to
the different pipe diameters are set out in
the following table.
Outside pipe diameter mm 16 20 25 32 40 50 63 75 90 110
Nominal diameter DN mm 10 15 20 25 32 40 50 65 80 100
Torque Nm 6 7 9 10 20 25 30 35 40 45