Case story





Belman engineered and manufactured eight High-pressure Bellows for installation in an open copper mining facility in Bulgaria. The large size of the Tied Bellows, which is DN 900 and 3.5 metres long, together with the extremely high-pressure operating conditions, set high demands for the Expansion Joint design.


CLIENT ISSUES – special requirements for the Bellows
The client turned to Belman with a request for Expansion Joints for a development project in its copper mine. These Expansion Joints needed to absorb axial and lateral movement and the installation position was horizontal outdoors (under atmospheric conditions). As the Bellows would be installed in an open space, the design temperature was specified at -21°C/42°C (as it gets cold during winter in the area of installation). In addition to absorbing movements under the specified design temperature and pressure of 22 barg, the Expansion Joints needed to accommodate possible future settlement of the terrain of the main support blocks and of the intermediate supports of the pipelines.



Large Expansion Joints for high pressure, large movement and low temperatures

To meet the requirements and needs of the client, Belman designed some special Tied Bellows. Due to the high pressure, the Expansion Joints are equipped with thick-walled flanges equipped with both holes for the tie rods and bolt holes for connecting the Expansion Joint to the mating flanges of the pipeline. The limiting tie rods are mounted for controlling the absorption of the axial and lateral movements, which explains the way the nuts are mounted. Due to the high pressure, a total of eight tie rods were mounted and secured to the middle pipe of the Expansion Joints to add stability. Thanks to this design, the Tied Bellows are able to absorb the +/-65 mm axial and the +/-30 mm lateral movement in combination under the operating pressure and temperature conditions. Due to the design temperature of -21°C/42°C, the material 1.4571 (AISI 316Ti) was selected, as it is suitable for very low temperatures (down to -270°C).


A returning client

Belman has already supplied several Expansion Joints for this mining facility. The exact same design used for this project was also supplied back in 2014 for another part of its pipeline. These Expansion Joints are still successfully operating.


Belman – expertise in Expansion Joints for mining

Since 1994, Belman has supplied numerous mining facilities around the globe. Having this vast experience enables us to design and manufacture sound and cost-efficient Expansion Joint solutions for the mining industry, irrespective of client needs or application. This expertise extends to remarkable knowledge and craftsmanship when it comes to special Expansion Joint requests such as low temperatures, lots of movement, high pressure and/or special alloys and materials. Read more here: Expansion Joints for the mining industry