HYDRAULIC SYSTEM 18000 SERIVCE/MAINTENANCE MANUAL
2-14 Published 12-05-17, Control # 035-23
Split Flange Connection
1. Lubricate and install O-ring in shoulder groove (see
Figure 2-12
). Align shoulder with port and assemble
flanges over shoulder.
NOTE: Bolts used must be grade-5 or better. Grade-5 bolt
has three dashes in head.
2. Snug bolts in a diagonal manner (Figure 2-12
) to 1/3 of
torque given in Table 2-6
.
3. Repeat step 2
to 2/3 of final torque. Repeat step 2 to
final torque.
Table 2-6 Split Flange Assembly Torque
Table 2-7 Split Flange Leakage
"A"
Dimension
inch
Flange
Size
Torque
in-lb Nā¢m
Standard Pressure Series
1-1/2 -08 175 ā 225 20 ā 25
1-7/8 -12 225 ā 350 25 ā 40
2-1/16 -16 325 ā 425 37 ā 48
2-5/16 -20 425 ā 550 48 ā 62
2-3/4 -24 550 ā 700 62 ā 79
3-1/16 -32 650 ā 800 73 ā 90
3-1/8 -24 1400 ā 1600 158 ā 181
3-13/16 -32 2400 ā 2600 271 ā 294
Port
Shoulder
Flange
O-Ring
FIGURE 2-12
S104
1
2
3
4
S101
Tube
High Pressure Series
1-9/16 -08 175 ā 225 20 ā 25
2 -12 300 ā 400 34 ā 45
2-1/4 -16 500 ā 600 57 ā 68
2-5/8 -20 750 ā 900 85 ā 102
3-1/8 -24 1400 ā 1600 158 ā 181
3-13/16 -32 2400 ā 2600 271 ā 294
Causes Cures
Flanges not tight.
Tighten bolts evenly to proper
torque.
Flanges tightened unevenly
causing extrusion of O-ring.
Replace O-rings. Tighten
bolts evenly to proper torque.
O-ring cut. Replace.
O-ring wrong size. Replace with proper size.
Sealing surfaces not smooth;
scratched or gouged.
Repair if possible or replace
parts.
Sealing surfaces dirty. Clean.
Flanges keep getting loose
in service.
Use SAE grade 5 bolts or
better. Retighten bolts after
system is hot.
"A"
Dimension
inch
Flange
Size
Torque
in-lb Nā¢m