O-Ring Face Seal Fittings
SMCS Code: 7553
O-ring face seal fittings
(1) O-ring face seal fitting. (2) O-ring groove. (3) Nut for the
O-ring face seal. (4) O-ring seal. (5) Straight thread O-ring
Ferrous Straight Thread O-Ring Fitting
9/16 - 18
25 3 Nm (18 2 lb-ft)
11/16 - 16
37 4 Nm (27 3 lb-ft)
13/16 - 16
54 5 Nm (40 4 lb-ft)
1 - 14
86 8 Nm (65 6 lb-ft)
1 13/16 - 12
125 15 Nm (90 11 lb-ft)
1 7/16 - 12
165 15 Nm (120 11 lb-ft)
1 11/16- 12
200 20 Nm (150 15 lb-ft)
2 - 12
225 20 Nm (165 15 lb-ft)
SMCS Code: 7553
The tightening sequence of the fasteners that
attach a tube assembly or hose assembly to the
machine is very critical to the proper function of
the machine. The sealing surfaces of the tube
assembly or hose assembly should be secured
squarely. The sealing surfaces of the tube
assembly or hose assembly should be tightened
cylinder, hydraulic motor, etc). Perform this
procedure prior to the final tightening of any
clamps or clips that are used in order to fasten
the tube assembly or the hose assembly to the
Installation of the Hydraulic Line
For a metal tube to hose installation, install the tube and
tighten all bolts finger tight at the rigid end.
Install the hose and tighten all bolts finger tight.
Put the hose in a position so that the hose does not make
contact with the machine or with another hose.
Tighten the bolts on both connections to the specified
Start the engine.
Move the implement control levers to all of the positions.
Look at the hose during movement of the implement.
Ensure that the hose is not in contact with the machine or
other hoses. Shut off the engine.
If necessary, put the hose in a new position so that the
hose will not make contact when the machine implement
Assembly of the Fittings with Straight
Threads and O-Ring Seals
This type of fitting is used in many applications. The tube end
of the fitting will be different in design so that the fitting can be
used in many different applications. However, the same
installation procedure for the fitting can be used. If the tube
end of the fitting body and the illustration (elbow or straight
body) match, it is necessary to assemble the sleeve on the
tube before connecting the tube to the end.