Torispherical head (Torispherical)
The most common and economical formed head for medium-pressure vessels
The torispherical head, known as the Klöpper head, is made from a spherical dome in the centre and a toroidal knuckle where it joins the body. The crown radius (CR) is taken as the vessel's outside diameter (Do) and the knuckle radius (KR) as at least 10 percent of Do; ASME UG-32 requires a minimum of 6 percent of Do for KR.
What is a torispherical head?
Torispherical means "torus + sphere": the central part is a section of a sphere and the edge is a section of a toroidal ring. The two arcs meet tangentially at a point and form the final head profile. After the knuckle, a short cylindrical edge (the straight flange) is added so that the weld joining it to the shell sits away from the high-stress knuckle area.
In DIN 28011, also called the Klöpper head, the dish radius equals the vessel's outside diameter and the knuckle radius is one tenth of it. The deeper version of the same family is DIN 28013, or Korbbogen, which has a smaller dish radius and a larger knuckle and is used at higher pressures.
Geometry formulas of the torispherical head
All dimensions of the head derive from the outside diameter and plate thickness. These few relations are the basis of this page's calculator:
The knuckle of the head becomes about 5 to 10 percent thinner after pressing. When calculating the nominal thickness, this thinning is taken into account together with the corrosion allowance so that the final thickness does not fall below the calculated value.
Online calculation
See the head's dimensions, volume and weight for a real diameter and thickness
Torispherical head (Torispherical)
Liquid level and volume inside this head
How the head is mounted
Development of this head (flat blank before forming)
The diameter of a flat plate of the same thickness and material that weighs the same as the formed head — an initial workshop estimate based on equal weight, not allowing for thickening or extra stretching at the knuckle.
The vessel head production process
From calculating the blank diameter to final edge preparation — the steps of making a vessel head in the workshop
Calculating the blank diameter
Cutting a disc from plate with the diameter and thickness calculated for the head type and vessel diameter
Cutting the plate blank
Precise cutting of steel or stainless plate by plasma, laser or gas according to the technical drawing
Pressing the head
Hot or cold forming of the disc with a die and industrial press until it reaches the final head profile
Edge preparation
Machining the edge, bevelling and preparing the weld area for fitting to the vessel shell
Video coming soonChoosing a head: the balance between pressure, cost and time
If your vessel's design pressure is in the medium range and the main priority is lowering fabrication cost, torispherical is usually the best option. For very high pressures or large diameters, where stress concentration at the knuckle becomes a concern, comparing it with the 2:1 elliptical head is recommended.
Gallery of heads we have made
Torispherical head gallery
Applications and industries served
Buying heads from Behineh Ab
Six steps from first contact to delivery
Give the outside diameter, plate thickness, head type and required material.
The calculated weight, unit price and delivery time are sent the same business day.
Plate is supplied with the mill certificate and inspected on arrival before cutting.
Cutting the disc, hot or cold pressing depending on thickness, and checking dimensions with a template.
Machining the cylindrical edge and bevelling it ready for welding to the shell.
Packing, issuing the part identification sheet and shipping nationwide.
What sets us apart
Price inquiry
vessel head
Enter the diameter, thickness and head type; you will receive the calculated weight and unit price.
- Quotation with the exact weight of the part
- Standard heads delivered in 7 business days
- Shipping nationwide
