The effect of residual stresses on the user properties of glass tubes

However, the user properties of the glassware are significantly affected not only by the absolute value of the residual stresses but also by the character of their distribution through the wall of the tubes and by the conditions of use [i]. During use, the glass tubes are subject to a steady load from the weight and pressure of the product to be transported, from the reaction from the supporting structure, temperature deformations, the pressure of the tensioning rubber rings of the flange or coupling attachment, and the variable loads from vibrations and from temperature, mechanical, and hydraulic impacts. As a result of these actions it is possible for dangerous extensive stresses to arise in the glass tube during use and this may occur both in the external and internal wall of the tube.