GENERAL HYDRAULIC SYSTEM REPAIR METHODS - Continued
RELIEVING HYDRAULIC PRESSURE - Continued
Do not apply sealant to the first threads of fittings. If sealant enters into the hydraulic system,
it may cause components to fail.
National Pipe Thread (NPT). This thread is commonly found in hydraulic systems. It differs from other fittings
in that 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 (Figure 1). Torque value guide in this work package, is NOT to be used.
DO NOT APPLY
National Pipe Thread (NPT).
37-Degree Flare. The 37-degree 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 37-degree flare fitting (Figure 2). These sealing surfaces must be
free of nicks and scratches in order to seal properly. If nicked or scratched, item must be replaced. For torque
requirements, see guide at end of work package.