Örnalp & Unozon logotyp


Site-built tanks and cisterns

We get into the game and can proudly say that we have become a complete supplier of site-built tanks and cisterns. We have no own products, which means that everything we produce is ordered by our customers. Through the years we have been working with custom made products, which enables us to offer unique experience and expertise. Not at least when it comes to welding in special materials and environments, including titanium and stainless steel. With our highly specialized experience, we primarily turn to you customers with extremely high standards of quality and performance. Each project has its own field of application and requires their own solutions.

We can solve them for you.



ÖrnalpUnozon design, engineer and produce advanced equipment for the industry. Our main products are heat exchangers, pressure vessels and process equipment. ViFlow also perform installation and maintenance of the products.

Wide technical expertise
ÖrnalpUnozon are characterized by wide technical expertise with a separate department for design, thermal calculation and product development. The expertise also extends to the application knowledge within our clients’ industries. We also have a sound know-how of materials and are licensed to work in virtually all materials.


We offer a complete line of tube heat exchangers!

ÖrnalpUnozon are specialists in designing, constructing and manufacturing tube heat exchangers. This type of heat exchangers can withstand extremely high pressure and high temperatures and therefore have many uses. Our specialty is to manufacture tube heat exchangers with dual supplies, such as titanium on the tube side and carbon on the shell side, which are joined together by so-called explosion bonding.

The thermal calculations required for designing the most advantageous tube heat exchanger for each installation are performed by our thermal engineers in HTRI software.

In order to be able to perform this, a number of parameters are required;

  • Temperature program
  • High/low pressure limits
  • Fluid flow capacity
  • Media
  • Size: any restrictions on the length and height

(please use the form below for faster feedback and suggestions from us)

ÖrnalpUnozon design shell and tube heat exchangers according to the European standard EN 13445 (PED) and the American ASME VIII Div 1 standard and we work in materials like titanium, acid proof steel, carbon steel, Hastelloy, SM0254, duplex, super duplex and Tantalum.


ÖrnalpUnozon design, engineer and manufacture pressure vessels for many different purposes, including reactors, columns, evaporators, vacuum vessels and bleaching towers.

Many of the materials we work with are expensive and difficult to process. Therefore, we design products in a manner that minimizes material usage. Our manufacturing processes are very efficient, which keeps the costs down for our customers. Our manufacturing unit, ÖrnalpUnozon, manufacture pressure vessels in titanium, acid proof steel, carbon steel, Hastelloy, SMO254, duplex and super duplex and master the pressure vessel standards:

EN 13445, EN 13480


ÖrnalpUnozon produce a range of customized products, such as equipment and machined parts to the process industry. Examples include screws, axles, trays, containers and insert tubes. These non-pressurized products are of the same high quality as ViFlow´s other products. The materials and the techniques we have specialized in are used in many different applications.


At ÖrnalpUnozon we also manufacture a range of customer-specific products. The materials and techniques we have specialized in are used in many exciting applications, including in the marine sector; for customers like Macgregor Cranes and Dockstavarvet we have, for example, manufactured the cabins to large ship cranes and components for Stridbåt 90. We have also manufactured many details on subcontract for BAE Systems. A bestseller for many years is our inspection hatch in stainless steel which can be delivered customized or in any of our standard sizes. See the attached brochure.

Please contact us if you have questions on manufacturing or cutting of specific details in any of the materials we specialize in.


ÖrnalpUnozon specialize in titanium and we know how to design, shape and weld customized products that keep high standards in strength and resilience, but also have a low weight. For the most part, we work with homogeneous materials, which is often the best and the cheapest. Sometimes other solutions are required, for example materials that are explosion welded with loose lining, where you dress a vessel with a thin titanium plate. Titanium is difficult to weld and requires special knowledge and protected environments because the material changes if it gets in contact with oxygen during the welding.

We weld according to standard EN ISO 3834-2 and all our welders are licensed to ensure a high and consistent quality of work. .


ÖrnalpUnozon offer total solutions including dismantling of existing pressure vessels and heat exchangers and installation of new ones.

Our customers are always offered qualified service and maintenance even after the delivered product and our employees are able to carry out repairs and supervision on site on short notice. Please contact us to learn more about our aftermarket services.