Pressure Vessel Dished End Heads – Complete FAQ & Technical Guide

Dished end heads are formed pressure-retaining closures used to seal the ends of cylindrical shells in pressure vessels, reactors, columns, heat exchangers, filters, separators, boilers, and critical tanks. Their curved geometry helps carry internal pressure and vacuum loads efficiently. At KRR Dished Ends, we manufacture heads for process industries including oil & gas, petrochemical, fertiliser, chemical, power, water, pharma, cryogenic and heavy engineering, with engineering support to match client drawings and code requirements.

Compared to flat ends, dished heads deliver higher pressure capability with lower thickness, because the curvature distributes stress more uniformly. This improves safety margins, fatigue performance, and long-term dimensional stability, while also reducing material weight in many cases. KRR supports the right selection ( torispherical /ellipsoidal/hemispherical) based on the duty conditions and applicable design code.

Dished heads help achieve code-compliant pressure containment, better stress distribution, and improved resistance to cyclic loading. They also enable practical nozzle layouts, smooth internal flow profiles, and efficient fabrication. With KRR’s manufacturing capability, customers also benefit from inspection-ready supply, controlled forming routes, dimensional checks, and documentation that supports EPC and third-party inspection workflows.

Not always. For low-pressure or atmospheric service, flat ends may be acceptable when code design and stiffening requirements are met. However, for most pressurised service and many vacuum cases, dished ends are preferred because they are more efficient and reliable. KRR can support selection by reviewing the service conditions and providing heads aligned to the governing code and fabrication practicality.

Dished heads are widely used in refining, petrochemical, chemical, fertiliser, power, EPC packages, water treatment, pharma/biotech, food processing, pulp & paper, cryogenics, and heavy engineering. KRR routinely supports both project (custom) heads and repeat supply programs where dimensional repeatability and documentation are critical.