● Installation

1. Cut a seamless steel pipe to the appropriate length and remove any burrs from the ends. The pipe ends must be perpendicular to the axis, with an angular tolerance of no more than 0.5°. If the pipe needs to be bent, the straight‑section length from the pipe end to the bend shall be at least three times the nut length.

2. Slip the nut and ferrule onto the seamless steel pipe. Pay attention to their orientation—do not install them backward.

3 Apply lubricant to the threads of the pre-assembled fitting body and the ferrule, insert the tube into the fitting body (making sure the tube is fully seated), and hand-tighten the nut.

4 Tighten the nut until the ferrule grips the tube; this transition point can be detected by an increase in tightening torque (the pressure point).

5 After reaching the pressure point, tighten the compression nut an additional 1/2 turn.

6 Remove the pre-assembled fitting body and inspect the seating of the ferrule’s cutting edge; any visible protrusions must completely fill the space at the ferrule end face. The ferrule may be slightly rotated, but it must not be axially displaced.

7. Final installation: Apply lubricant to the threads of the fitting in the actual installation, then tighten the nut until you feel a noticeable increase in tightening torque. Finally, tighten an additional 1/2 turn to complete the installation.

● Reinstall

All ferrule fittings can be reassembled multiple times, provided that all components remain undamaged and clean.

1 Insert the tube into the fitting body until the ferrule is tightly seated against the internal conical surface, then hand-tighten the nut.

2 Use a wrench to tighten the nut until the tightening torque increases sharply, then tighten it an additional 1/4 to 1/2 turn.

● Inspection

The tube can be removed to verify that the assembly meets the required specifications: the tube at the ferrule end should exhibit a uniform, slight protrusion. The ferrule must not slide axially but may rotate slightly.

● Cause of the leak

1 The tube wasn’t inserted all the way.

2 The nut is not tightened.