The sealing and fastening of the double ferrule tube fittings depend on the precise fit and deformation of the front and rear ferrules. The front ferrule is mainly responsible for sealing, while the core function of the rear ferrule is to radially grip the pipe and provide anti vibration capability.
Follow the following steps during installation:
1. Pipe preparation and preliminary installation
Improper handling of pipes: The end face of the pipe must be perpendicular to the axis, with a recommended angle tolerance of no more than 0.5 °, and burrs inside and outside the port must be thoroughly removed. Any slanted edges or burrs can affect the even fit of the double ferrule, leading to medium leakage.
Reverse assembly of double ferrule components: It is important to ensure the correct assembly sequence: first, place the nut on the pipe, then install the rear ferrule, and finally the front ferrule. Be careful not to install the direction in reverse.
2. Tightening operation and quality control
The pipe is not fully inserted: During installation, the pipe must be firmly inserted into the double ferrule tube fittings body until it presses against the internal pipe shoulder. This is the basis for ensuring that the double ferrule forms a seal in the correct position. If the pipe is not fully inserted, it will cause complete failure of sealing.
Inaccurate tightening turns: This is the most critical step.
The general operation is: after inserting the pipe to the bottom, tighten the nut with your fingers until you feel unable to move it.
Make a mark at the 6 o'clock position on the sleeve nut.
Use a double wrench, one to fix the fitting body and the other to rotate the nut 1 and 1/4 turns (540 degrees) to move the mark to the 9 o'clock position. Make sure to tighten the number of turns accurately.
Ignore pre installation check: A pre installation can be performed before the official installation. After completing the above steps, loosen the nut and check if the edge of the front ferrule has been evenly cut into the surface of the pipe, forming a complete protruding ring. This can effectively verify the installation quality.
