BOA Expansion Joints
The Rodin Group offers a wide range of BOA expansion joints, suitable for numerous specific applications.
According to their physical properties, most metals expand when temperatures increase and contract when temperatures decrease. In pipeline systems, this behaviour results in variations in the length of individual pipeline sections. As pipelines are normally anchored at least at two connection points, any change in length will generate thermal strain in the material, as well as increased forces and moments at these terminal points.
Where possible, the inherent flexibility of a pipeline is utilised to compensate for thermal expansion (natural compensation). However, if the expansion exceeds the inherent flexibility of the pipe, expansion joints are required to accommodate these movements.
In addition, mechanical vibrations from pumps, compressors, turbines and motors should be dampened in order to prevent damage to adjoining pipelines, supports or installed instruments. Forces and moments on the nozzles of compressors, turbines, vessels and other plant components are limited and must not be exceeded. In such cases, expansion joints can be employed to provide effective compensation.
The central component of each expansion joint is the metal bellows (except for rubber expansion joints), which functions as a spring due to its shape and thin wall. The bellows must satisfy the following basic criteria in order to be suitable for use as an expansion element:
- withstand the operating and test conditions (pressure and temperature) of the pipe system
- ensure corrosion resistance against both internal (flow) and external (atmospheric) conditions
- provide sufficient flexibility to compensate for thermal expansion and mechanical vibrations with the required durability (life expectancy)
- offer adequate squirm stability
Expansion Joints with Stainless Steel Bellows
BOA offer a wide range of expansion joints suitable for numerous specific applications.
The BOA expansion joint portfolio consists of three main series:
- Standard Series: expansion joints up to DN 150 (6″)
- Industrial Series: expansion joints up to DN 1,000 (40″)
- Special Series: expansion joints above DN 1,000
The core of all expansion joints is the metal bellows. Owing to modern design and manufacturing capabilities, all BOA expansion joints provide the following advantages:
- high flexibility
- short build length
- large movement capacity
- durability and excellent chemical resistance
We employ almost every established type of bellows forming to ensure the best possible solution for our customers. These include hydraulic forming, elastomer forming, punching and mechanical rolling.
