Non-metallic expansion joints, also known as non-metallic compensators, are mainly used to absorb thermal expansion and contraction, vibration, displacement, etc. in pipeline systems, and are commonly used in pipelines with high temperature, high pressure and corrosive media. When installing non-metallic expansion joints, it is essential to follow the correct specifications to ensure their proper operation and extended service life. Here are some key installation specifications and steps:
Preparation：
Before installation, the installation instructions provided by the supplier should be read carefully.
Check whether the model, size and related parameters of the expansion joint are consistent with the design drawing.
Confirm that there are no foreign matter inside the skin and pipe, and ensure that the expansion joint is used smoothly.
Installation Environment：
Ensure that the installation area is clean to avoid dust, sand and other impurities entering the inside of the expansion joint.
Avoid damage from impact, scratches, arc ignition and welding splashes when transporting and hoisting.
Installation process：
During installation, the deformation of the expansion joint (axial, transverse, torsional) is not applied to correct the installation error of the piping system.
Do not weld any temporary supports to the bellows, and avoid strapping the slings directly to the bellows during hoisting.
Ensure that the non-metallic expansion joint is not subjected to additional external or pulling forces, especially when connected to fan equipment.
If the expansion joint has flow direction requirements, it should be properly installed as indicated by the media flow direction arrow.
Brackets and positioning：
There should be sufficiently long straight pipe sections before and after installation, and it is generally recommended that the length of straight pipe should not be less than 100mm.
Set the supports and hangers correctly, calculate the pipe thrust and the strength of the fixed bracket, and ensure the expansion energy-saving free movement.
Adjust the tie rod to accommodate the tensile allowance of the non-metallic fabric, but do not remove it completely to prevent excessive external tension.
Special Notes：
For large-sized non-metallic expansion joints, site assembly may be required to ensure that the components are properly aligned.
Once the installation is complete, loosen the inner nut of the expansion joint and keep it properly pre-stretched or pre-compressed.
Inspection and commissioning：
After installation, perform a system pressure test to check the tightness and functionality of the expansion joint.
It is confirmed that the expansion joint can expand and contract freely within the design range, and there is no jamming phenomenon.
Keep in mind that specific installation specifications may vary from manufacturer to manufacturer, so it is important to always refer to the installation manual for a specific product. If you encounter uncertainty, you should consult a professional installer or manufacturer's technical support.