The compression and stretching of the expansion joint is one of its most basic functions, mainly to adapt to the thermal expansion and contraction effects due to temperature changes in the pipe system. The compression and tension of the expansion joint are detailed below:
compression
When the temperature of the medium in the piping system drops, the pipes are shortened by cooling. The expansion joint absorbs this shortening through the compression of its bellows, thereby avoiding excessive stress in the piping system.
Features of compression:
Compression direction: The corrugations of the expansion joint bellows are compressed, and the distance between the crest and the trough becomes smaller.
Location change: When the expansion joint is compressed, its length will be shortened.
Action: By compression, the expansion joint absorbs the shortened displacement produced by the piping system as it cools.
Stretching
When the temperature of the medium in the piping system rises, the pipes can elongate due to heating. The expansion joint absorbs this elongation through the stretching of its bellows, again to avoid excessive stress on the piping system.
Characteristics of stretching:
Stretching direction: The corrugations of the expansion joint bellows are stretched, and the distance between the crest and the trough becomes larger.
Location change: The length of the expansion joint increases when it is stretched.
effect: By stretching, the expansion joint absorbs the elongation displacement generated by the piping system when heated.
Precautions in practical application
Design Calculation：
In the design stage, it is necessary to accurately calculate the temperature variation range and the expansion and contraction amount of the expansion joint to ensure that the expansion energy saving effectively compensates the displacement.
Other constraints in the plumbing system, such as the location and type of bracket, also need to be considered.
Installation direction：
When installing the expansion joint, ensure that the direction of the arrow of the expansion joint coincides with the direction of the media flow.
In addition, it is necessary to ensure that the displacement direction of the expansion joint is consistent with the design requirements.
Supporting structure：
The support structure around the expansion joint needs to be designed to be flexible enough to allow the expansion joint to expand and contract freely, but at the same time to be robust enough to support the expansion joint and the piping system.
Check periodically：
Check the condition of the expansion joint regularly to ensure there is no damage or leakage.
Check whether the expansion joint expands and contracts normally according to the design requirements.
Maintenance and maintenance：
Maintenance is performed according to the manufacturer's recommendations to ensure the long-term performance of the expansion joint.
Summary
The expansion joint absorbs displacement in the piping system through the compression and stretching of its bellows to alleviate or eliminate thermal stress caused by temperature changes. Proper calculation and installation of expansion joints is essential to guarantee the safe operation of your piping system.