8.1.7
Tapered Pipe Thread Fittings
The proper method of assembling a pipe thread fitting is:
1.
Check components to ensure that fitting and port threads are free of burrs, nicks and scratches, or any form of
contamination.
2.
Apply pipe thread sealant (paste type) to the external pipe threads.
3.
Thread the fitting into the port until hand-tight.
4.
Torque the connector to the appropriate torque angle. The Turns From Finger Tight (TFFT) values are shown
in Table
8.10 Hydraulic Fitting Pipe Thread, page 95
. Making sure that the tube end of a shaped connector
(typically 45º or 90º) is aligned to receive the incoming tube or hose assembly. Always finish alignment of fitting
in the tightening direction. Never back off (loosen) pipe threaded connectors to achieve alignment
5.
Clean all residue and any excess thread conditioner with the appropriate cleaner.
6.
Assess the final condition of the fitting. Pay special attention to the possibility of cracks to the port opening.
7.
Mark the final position of the fitting. If a fitting leaks, disassemble the fitting and check for damage.
NOTE:
*Over-torque failure of fittings may not be evident until the fittings are disassembled.
Table 8.10 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
214017
95
Revision A
