GENERAL HYDRAULIC SYSTEM REPAIR-CONTINUED
The following information is provided to familiarize personnel with the various types of hydraulic fittings.
Refer to this section and the warning and cautions on the previous pages when working on hydraulic systems.
National Pipe Thread (NPT) is commonly found in hydraulic systems. It differs from other fittings because it
is tapered. In order to obtain a proper seal with this thread, you must use a sealant. The sealant should be
applied to the male fitting. Torque valve guide, in appendix, is NOT to be used.
Do not apply sealant to the leading edge or the first thread of hydraulic fitting, or sealant
may get into the hydraulic system and contaminate it. Failure to comply may result in
damage to equipment.
flare termination has a male straight thread that mates with a female straight thread. The sealing surface
for this termination is the angled nose at the end of the male fitting. This nose mates with a similar surface in
the female 37flare fitting. These sealing surfaces must be free of nicks and scratches in order to seal properly.
If nicked or scratched, item must be replace. For torque requirements, see guide in appendix.