8.1.8 Tapered Pipe Thread Fittings
Assemble pipe
fi
ttings as follows:
1. Check components to ensure that
fi
tting and port threads are free of burrs, nicks and scratches, or any form of
contamination.
2. Apply pipe thread sealant (paste type) to external pipe threads.
3. Thread
fi
tting into port until hand-tight.
4. Torque connector to appropriate torque angle. The Turns From Finger Tight (T.F.F.T.) values are shown in Table
8.14 Hydraulic Fitting Pipe Thread, page 91
. Make sure that tube end of a shaped connector (typically 45º or 90º)
is aligned to receive incoming tube or hose assembly. Always
fi
nish alignment of
fi
tting in tightening direction.
Never back off (loosen) pipe threaded connectors to achieve alignment.
5. Clean all residue and any excess thread conditioner with appropriate cleaner.
6. Assess
fi
nal condition of
fi
tting. Pay special attention to possibility of cracks to port opening.
7. Mark
fi
nal position of
fi
tting. If a
fi
tting leaks, disassemble
fi
tting and check for damage.
NOTE:
Overtorque failure of
fi
ttings may not be evident until
fi
ttings are disassembled.
Table 8.14 Hydraulic Fitting Pipe Thread
Tapered Pipe
Thread Size
Recommended
T.F.F.T.
Recommended
F.F.F.T.
1/8–27
2–3
12–18
1/4–18
2–3
12–18
3/8–18
2–3
12–18
1/2–14
2–3
12–18
3/4–14
1.5–2.5
12–18
1–11 1/2
1.5–2.5
9–15
1 1/4–11 1/2
1.5–2.5
9–15
1 1/2–11 1/2
1.5–2.5
9–15
2–11 1/2
1.5–2.5
9–15
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91
Revision A
