Pressure Vessel
Decundi Inspection has many inspectors who are highly skilled in the fabrication and testing of pressure vessels. During the fabrication of pressure vessels, the inspections carried out by Decundi's inspectors include but are not limited to checking the welding consumables prior to welding and monitoring of preheating plus monitoring the amperage and voltage during welding of longitudinal and circumferential joints (long seams and girth seams) on shell rings (cans) for pressure vessels. In addition, our inspectors also carry out inspections after the back gouging of long seams and girth seams for verification that the background areas are carried out to sound metal and for assurance that smooth grinding is carried out at the background areas. Examination by either magnetic particle testing or liquid penetrant testing (depending on the material of construction of the pressure vessel) is also carried out in the background areas. After welding inspection, checks are also carried out for the height of weld reinforcement at the long seams and girth seams for compliance with UW-35 of the code.
During the fabrication of pressure vessels, Decundi inspectors also carry out final dimensional inspections where these inspections include a check for verification for the levelness of the vessel on the positioning rolls where the levelness of the vessel is checked in the horizontal plane, and for vessels with a skirt or vessels with anchor chairs, these pressure vessels are also checked in the vertical plane or at the base plate or anchor chairs as applicable.
Decundi inspectors also carry out inspections for the installation of nozzles and manways, and these inspections include checks for five (5) parameters which are noted to be the elevation, orientation, projection, 2-hole, and levelness for the fit-up and welding of nozzles and manways installed in the shell and heads of pressure vessels. Inspection checks are also carried out for permissible out-of-roundness of cylindrical, conical, and spherical shells for compliance with UG-80 of the code. Final dimensional inspection of pressure vessels also includes checks for verification of the serrations on the gasket surface areas on nozzles and manways for finishes ranging from 125 to 250 μin (3.2 μm – 6.3 μm) or finishes as required by project specification. Dimensional checks are also carried out for the overall length of pressure vessels, and in addition to this, a review of radiographs and other test reports, which include but are not limited to material test reports (MTRs), is carried out prior to hydro testing of pressure vessels.