INFLUENCE OF WELDED ASSEMBLY QUALITY ON THE APPARATUS CASING OPERATION RESOURCE

Abstract

Background A steel welded vessel or apparatus designed and manufactured in accordance with State Standard R 52630-2006 assumes a long service life and withdrawal for repairs in cases not related to the failure of the apparatus due to a violation of its shell, body defects, welds and de- forming the walls of the shell. The technology of the vessel assembly assumes the presence of a stress-strain state in the zones of edge action, in the places of installation of the choke units, in places where the longitudinal joints are more concentrated. For reliable operation of the fittings, in order to ensure safe operation of the apparatus and the enterprise as a whole, various types of reinforcement are used, including reinforcing rings, which, according to State Standard R 52630-2006, can have a gap between the ring and the vessel body of not more than 3 mm. As practice shows, the real size of the gap is several times higher than the allowable value, that is, full access is not provided. The work carried out by various organizations to diagnose the technical condition and determine the residual life of hazardous production facilities does not include the examination of this node for the presence of an overestimated gap and, accordingly, does not take into account the impact of this negative factor. Aims and Objectives The search for new methods for monitoring the size of the gap in the fitting nuts, both at the periphery of the ring and near the nozzle, and also the ways to introduce it into the limits corresponding to the norms, is one of the urgent problems in the manufacture of equipment. Results The performed calculations of the stress-strain state in the reinforcement zone of the chassis unit of the apparatus body, as well as practical tests showed that with an increase in the clearance at the junction of the nozzle with the shell, internal stresses increase up to 20 %, while the service life of the chuck-mounted choke unit may decrease by 18 %.