Common problems and solutions for the installation of single card sleeve connectors

1、 Improper pipeline pretreatment

Cutting deviation: The pipe end is not cut vertically (allowable angle deviation ≤ 0.5 °) or burrs are not removed, resulting in uneven cutting of the sleeve.

Suggestion: Use a specialized pipe cutter, polish the end with a deburring tool after cutting, and measure the verticality of the pipe end.

Surface pollution: Residual metal shavings or oil stains on the inner wall of the pipeline, affecting the sealing performance.

Suggestion: Before installation, blow the pipeline with compressed air and wipe the inner wall with non-woven fabric.

2、 Pre installation operation error

Reverse installation of card sleeve: Failure to correctly distinguish the installation sequence of the front card sleeve and the rear card sleeve, resulting in seal failure.

Suggestion: Follow the sequence of "nut → sleeve → pipe insertion into joint body" to ensure that the conical surface of the sleeve faces the joint body.

Insufficient/excessive pre tightening force:

Shortcoming: The benchmark of "initial tightening by hand+1.25 turns by wrench" has not been reached, and the card sleeve has not formed an effective sealing line.

Excessive: Exceeding the recommended number of turns (usually total tightening turns ≤ 1.75 turns) can cause excessive deformation of the sleeve and even damage to the pipeline.

3、 Sealing performance issues

Leakage detection blind spot

Static leakage: After installation, no pressure holding test (at least 30 minutes) was conducted at 0.8-1.5 times the working pressure.

Dynamic leakage: Loose joints were not checked in a vibrating environment (regular tightening is required, torque error ≤ ± 10%).

Sealing ring failure: Failure to select materials based on the characteristics of the medium (such as fluororubber oil resistance, EPDM acid and alkali resistance), or installation not centered, resulting in bias.

4、 Insufficient response to special working conditions

High pressure pulsation environment: Failure to use a double sleeve structure or install shock-absorbing brackets resulted in fatigue cracking of the joint.

Extreme temperature: The pipeline is not pre cooled below -20 ℃, and 316L stainless steel material is not used for high temperatures (>150 ℃).