Large Custom Pressure Vessel & Tank Heads
Pressure vessel heads (often called dished heads or tank heads) are the critical end closures of cylindrical pressure vessels. Because they are subjected to immense internal pressures, their manufacturing requires flawless forming techniques, strict metallurgical control, and absolute compliance with international safety codes like ASME Section VIII.
Openex operates world-class heavy forming and pressing equipment, allowing us to manufacture massive, heavy-wall pressure vessel heads. Whether your design requires semi-elliptical, torispherical, hemispherical, or conical heads, our 180-acre facility can form, treat, and machine tank heads up to 10 meters in diameter and up to 300mm thick.
Tank Head Manufacturing Specifications
We custom-form large dished heads to your exact engineering drawings and code requirements. Below are our general facility capacities:
| Maximum Diameter | Up to 10,000 mm (10 Meters) |
|---|---|
| Maximum Thickness | Up to 300 mm (Cold/Hot Spun & Pressed) |
| Head Types Produced | Semi-Elliptical (2:1), Torispherical, Hemispherical, Conical, Flat, and Custom Flanged. |
| Materials Processed | Carbon Steel (A516 Gr 70), Stainless Steel (304/316/321), Duplex, Nickel Alloys, and Clad Plates. |
| Certifications & Codes | ASME Section VIII Div. 1 & 2 (U/U2 Stamps), PED (CE), ISO 9001, API. |
The Manufacturing Process
Forming a massive, heavy-wall pressure vessel head requires a highly controlled, multi-step process to ensure structural integrity and dimensional accuracy.
If the required head diameter exceeds the size of a single steel plate, we perform multi-pass, full-penetration SAW welding to splice plates together. The welds are 100% RT (Radiographic) tested before forming begins.
Using massive hydraulic presses and flanging machines, the blank is pressed into its crown radius (dishing) and then spun to create the knuckle radius and straight flange. Depending on thickness and material, this is done cold or hot.
Heavy forming introduces extreme residual stresses. The formed heads are moved into our massive on-site furnaces for Normalizing or Post-Weld Heat Treatment (PWHT) to restore the metal's mechanical properties.
Finally, the head is mounted on a large Vertical Turning Lathe (VTL). We machine the outer flange and create precise weld bevels (V, J, or U-grooves) so it is ready for immediate fit-up and welding to the vessel shell.