How to buy a qualified Self-lubricating sleeve

01 inspection report

Check the inspection report issued by the manufacturer when purchasing Self-lubricating sleeve. The validity period of the inspection report is four years, which is to inspect whether the sleeve produced by the sleeve manufacturer is qualified under the conditions of specific material, appearance size and thread parameters.

02 check whether the self-lubricating sleep is consistent with the inspection report

Check whether the self-lubricating sleeve materials are consistent with the raw material category and steel grade used in the inspection report, and compare the sleeve raw materials provided by the manufacturer.

On the market, sleeve raw materials are usually divided into two categories: 45 steel and low carbon steel. No matter which material is used, the annealing test report shall be checked.

If 45 steel is not annealed, its tensile strength can also pass the inspection, but it can not meet the deformation index, another important performance index of the joint.

If the low carbon steel is not annealed, the tensile strength is also qualified, but in case of fire, the sleeve will be heated, the stress will disappear, the tensile strength of the sleeve will drop to about 400MPa, and the sleeve will be broken into two sections. The fire performance of this kind of low carbon steel sleeve is poor, and it is difficult to meet the fire rating requirements of buildings.

03 check whether the size of self lubricating sleep is qualified

Reasonable and sufficient length, outer diameter and inner diameter are the essential factors for selecting sleeve.

The self reinforcing sleeve used in steel bar connection will have corresponding size specification. In order to save steel, some small manufacturers will cheat on the specification and size of the sleeve and cut corners. The outer diameter of the sleeve produced is less than the minimum value required by the specification. Although it can meet the tensile requirements, it reduces the safety factor of the joint and has structural hazards.

04 check Self-lubricating sleeve logo

The qualified self-lubricating sleep shall have the manufacturer identification and production batch number, and the production batch number shall be consistent with the production batch number marked in the raw material inspection report and ex factory tensile strength inspection report, so as to ensure the real traceability of the product.

05 check whether the product certification documents of Self-lubricating sleeve are complete, true and effective

As a safety product of engineering structure, the quality certificate of self-lubricating sleeve is particularly important, which is the basic basis for liability analysis, accountability and traceability of engineering quality accidents. If we do not pay attention to the lack of information when purchasing self-lubricating sleeve, it will be impossible to verify whether the quality of sleeve used in the project is qualified and cannot be accepted. The sleeve manufacturer shall provide authentic, effective and complete quality certificates.