Horizontal vessels on fixed supports used for storing high-temperature liquid: an experimental validation of finite element modelling

Horizontal cylindrical storage vessels are normally supported on two saddle s. When used for storing high-temperature fluid high values of thermal stre ss can be avoided by providing one of the supports with a sliding base. How ever, this ideal may be difficult to achieve in practice and vessels are so metimes found where both saddles have become rigidly fixed to the foundatio n. In view of this there may be certain advantages in dispensing with the c oncept of a sliding saddle support altogether and installing the vessels wi th both saddles permanently fixed to the foundation. Where this is adopted the vessels and saddles must be designed to carry the thermal stresses that arise from the imposed restraint of the saddle base. Since this procedure is outside normal practice, as set out in the existing pressure vessel code s and standards, it is necessary to undertake detailed analytical investiga tions, say, using finite element analysis (FEA), to establish the behaviour of the vessels when this approach is used. In order to validate the predic tions of temperature and stress obtained from the FEA used in the investiga tions, it was considered important to carry out some experimental work. Thi s paper reports the techniques used and describes two experimental procedur es which were performed on vessels mounted on two quite different saddle de signs, both of which are widely used in industry.