Cylinder(s)
L5/11
LT12
Operation sequence
LT5/11-
LT5/11-
low-
high-
pressure
pressure
Remove spring (10), outlet valve guard (9)
and outlet valve disc (8).
Lift off valve seat (7) and remove Inlet
valve disc (6). Do not remove guide pins
(2).
Remove and discard all the O-rings and
rubber cord joints.
Remove the carbon deposits from the inlet
valve guard at the cylinder top. Take care
that no dirt drops Into the cylinder.
Clean and inspect all the parts. Discard
any valve discs that are cracked or worn.
Fit new rubber cord joint (3). Do not
stretch the rubber while Inserting it in Its
groove the ends should meet. Lightly
smear the cords, O-rings and their grooves
with graphite grease.
Cylinder(s)
15/11
LT12
Operating sequence
LT5/11-
LT5/11-
low
high-
pressure
pressure
Put inlet valve disc (6) into place and install
valve seat (7)
Fit O-ring (5) and cord joint (1).
Install outlet valve disc (8), guard (9) and
spring (10).
Install cylinder head cover (11). Use new
flange gaskets, it necessary. Fit the flange
and cylinder head bolts and tighten them
alternately
Fit O-ring (13) and cord (12). Reinstall in-
and outlet caps (14 and 15), reconnect
outlet pipe coupling and flanges, reinstall
cover (11) and clamp cylinder head
assembly securely into place
Reinstall the fan guard and the cover of the
air intake silencer
Drawing E
L5 to 9 and low pressure side of LT5 to 11
Drawing F
High pressure side of LT5 to 12 and low
pressure side of L11 and LT12
1.
Rubber cord joint
2.
Guide pin (2 off)
3.
Rubber cord joint
4.
Cylinder
5.
O-ring
6.
Inlet valve disc
7.
Valve seat
8.
Outlet valve disc
9.
Outlet valve guard
10.
Spiral spring
11.
Cylinder head cover
12.
Rubber cord joint
13.
O-ring
14.
Inlet cap
15.
Outlet cap
Figs. E and F - Cylinder head valve assemblies
Torque chart
Key number
Torque (ft -lb)
Unloader valve
Torque (ft.-lb)
6 mm
7.5
8 mm
11
8 mm
18.5
10 mm
33
7 Data
L/LT5
L/LT6
L/LT7
L/LT8
L/LT 9
L/LT11
LT12
Crankcase oil capacities ......................................................... I
1.40
1.40
3.00
3.00
5.40
5.40
5.40
U.S. gal
0.37
0.37
0.79
0.79
1.43
1.43
1.43
Atlas Copco Standard Pneumatic reserves the right to alter the configuration of their compressors without notice
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