ASSESSMENT OF RELIABILITY OF VESSELS

Reliability assessment shall be made at the various stage of construction depending on the classification of the vessel. The manufacturer shall keep the purchaser or the inspecting authority informed of the progress of the work and shall notify the inspector reasonably in advance when the vessel has reached the required stage of inspection.

INSPECTION DURING MANUFACTURE

All materials to be used for pressure parts of vessels shall be inspected before fabrication for the purpose of detecting defects which may affect the safety of the vessel.

Special attention shall be paid to the cut edges and other parts of rolled materials which may disclose the existence of serious laminations, shearing cracks and other objectionable defects.

Defect shall not be repaired unless inspected and approved by the inspecting authority.

INSPECTION DURING FABRICATION

The inspector shall make inspections of each vessel at such stages of fabrication as he / she deems necessary to assume himself / herself that the fabrication is according to code requirements.

The edges of plates, openings and fittings exposed during manufacture shall be examined for defects.

Before assembly, all shell sections, ends, rings, etc., shall be examined for conformity to prescribed shape and checked for thickness and dimensions.

The component parts of the vessel shall be assembled and checked for alignment of matching edges. Special attention shall be paid to assembly of branches and to their reinforcement.

When conditions permit entry into the vessel, as complete an examination as possible shall be made before the final closure.

Heat Treatment Check: The inspector shall satisfy himself that stress relieving procedure or other heat treatment, as may be necessary, has been correctly carried out.

INSPECTION OF COMPLETED PRESSURE VESSELS

Visual inspection - During the final inspection of the whole vessel the surfaces of the welds are to be inspected visually and judged as meet the standard specifications.

Records of manufacturing details, inspection and tests shall be kept by the manufacturer and shall be available for the inspecting authority for examination, whenever required.

Radiography Examination - Radiographic examination of welded joints shall be carried out.

 

PRESSURE TESTS

The finished vessel shall, in the presence of the inspecting authority, pass satisfactorily such of the following pressure tests as may apply.

Standard Hydrostatic Test: For simple vessels where thickness of all pressure parts can be calculated.

Proof  Hydrostatic Test: For complex vessels the thickness of which cannot be computed with a satisfactory assurance of accuracy and for which the maximum working pressure has to be based upon the distortion pressure.

Pneumatic Test: For vessels so designed and or supported that they cannot be safely filled with the testing liquid or for vessels that are to be used in services where even small traces of the testing liquid cannot be tolerated.

WELD SEAM TEST - RADIOGRAPHY

It covers the radiographic examination of all longitudinal and circumferential butt welds in drums, shells and headers throughout their whole length including points of intersection with other joints.

Thank You for reading the page. Please follow the blog for information on Safety Jobs, Industrial Safety, Fire Safety and Construction Safety courses study material.

Visit and subscribe our YouTube channel Being Safety Officer for safety videos.