Glass pipes and plants are characterised by outstanding reliability and performance with low maintenance costs. The mechanical stability of glass is limited, however. A flexible joint concept allows pressure and vacuum-tight assembly of piping systems with no mechanical stresses.
The outstanding characteristics of borosili-cate glass 3.3 meet the requirements for process equipment in the chemical and pharmaceutical industries. Borosilicate glass 3.3 offers excellent corrosion resis-tance to a large number of chemicals, especially strong acids. Its smooth, non-porous surface reduces deposits and incrustations practically to zero. The transparency of the material permits processes to be continuously observed. In addition to these clearly positive features, glass has also several disadvantages. The mechanical stability of glass is limited, and in particular the permissible tensile and bending stresses are small. Various measures are necessary to overcome these negative aspects.
The modular glass piping system from Büchi covers a vast range of standard components with nominal diameters ranging from DN 15 to DN 600, all featuring ball joint connections. The büchiflex pipe joint plays a crucial role in this modular system. Pressure and vacuum-tight, yet still flexible, this connection facilitates assembly with no mechanical stresses. Axial and radial movements of the glass components and piping, caused by changes in temperature or level, are permitted, since no mechanical forces are produced. The actual seal is formed by a PTFE O-ring, which is positioned in the groove of the ball joint. Both pipe ends of this flexible connection, in other words the ball and socket, are flame-polished. The wetted materials that come into contact with chemicals are made of non-porous plain glass and PTFE. Entire plants can be designed with the büchiflex system, eliminating the need for expansion joints and bellows and additionally leading to a reduction in possible dead volumes and potential sources of contamination. Together with the extensive plant documentation, these characteristics ensure that GMP requirements are optimally complied with. Planning and design are aided by a state-of-the-art 3D CAD system. Cus-tomers have access to the 3D software needed to visualise and review drawings from the planning phase onwards.