Experiments and FEA on Horizontal Pressure Vessels Under Thermal Expansion

Abstract

This paper reports on the numerical and experimental research on saddle mounted horizontal pressure vessels subjected to heating by its hot liquid contents. The overall purpose of the research is to obtain design formulae relating design variables of horizontal pressure vessels mounted on fixed non-sliding saddle supports. Two experimental techniques were utilised to obtain stresses and strains for the situation of the saddle supports being rigidly fixed to ground. The first technique involves room temperature testing whereby one saddle base is displaced by the expected thermal expansion displacement (i.e. isothermal push-pull). The other technique utilised direct thermal heating by introducing hot liquid into the vessel, a more complicated yet more realistic test. These two techniques are not equivalent because in the hot test, the vessel will expand both axially and radially, whereas the radial expansion will be absent in the isothermal push-pull test. Experimental tests were conducted for the above two loadings techniques on two model vessels with different saddle designs. The resulting strains measured at the maximum stress locations showed that they can be reliably predicted when push-pull tests are carried out. Additionally, FE analyses were conducted for the two techniques for comparison. The experimental results are discussed with the FE predicted values, with particular reference to their agreement with push-pull tests and the hot liquid tests.