Compliant with DIN 28011 · DIN 28013 · ASME

Fabrication of all types of heads for pressure vessels

A vessel head is not just a cover; its geometric shape directly affects three parameters: the amount of plate used to form it, the difficulty of forming (and therefore the fabrication cost), and the stress distribution in the body, which sets the allowable working pressure. A hemispherical head is the most efficient shape mechanically but the most expensive to make, while a flat head is the cheapest but the weakest against internal pressure.

Workshop photo — pressing a pressure vessel head
Pressable diameter
300 to 7,000 mm
Plate thickness
4 to 45 mm
Forms we make
11 types
Standard head delivery
7 to 45 days

Comparing head types

Choose a form to see its geometry, ratios and use

DIN 28011 · Torispherical

Klöpper head

The most widely used form for medium-pressure vessels. A dish with a radius equal to the vessel diameter and a small knuckle; low height, simple pressing and an economical price — the default choice for compressed air and water vessels.

Crown radius
R = Do
Knuckle radius
r = 0.1 Do
Dish height
h ≈ 0.194 Do
Pressure rating
Medium — up to 10 bar
Most economical optionSingle-stage pressing
Torispherical

Torispherical

  • CR = Do
  • KR = 0.1 × Do
  • SF ≥ 3.5 × t
  • DH = 0.1935×Do − 0.455×t
  • THi = SF + DH
  • DH 270 mm
  • THi 312 mm
  • KR 142 mm
  • CR 1416 mm
  • SF 42 mm

Table of geometry and ratios

The standard ratios of each form based on the vessel's outside diameter

Head type
CR (crown radius)
KR (knuckle radius)
DH (approx. depth)
Torispherical (Klöpper)
Do
0.1×Do
From CR and KR
2:1 elliptical
0.9×Di
0.17×Di
0.25×Di
1.9:1 elliptical (NF E 81-103)
Di/1.16
Di/5.39
Di/3.8
DIN 28013 semi-ellipsoidal
0.8×Do
0.154×Do
From CR and KR
Hemispherical
0.5×Di
—
Equal to CR
Standard dished
Di
15 to 50 mm
From CR and KR
Diffuser
1.3×Di
15 to 50 mm
From CR and KR
Flat
—
Min. 0.06×Di or 25 mm
Equal to KR
Plate type
Di
—
Very shallow
Convex disc
Do (to 0.8×Do)
—
≈0.134×Do

The vessel head production process

From calculating the blank diameter to final edge preparation — the steps of making a vessel head in the workshop

  1. Calculating the blank diameter

    Cutting a disc from plate with the diameter and thickness calculated for the head type and vessel diameter

  2. Cutting the plate blank

    Precise cutting of steel or stainless plate by plasma, laser or gas according to the technical drawing

  3. Pressing the head

    Hot or cold forming of the disc with a die and industrial press until it reaches the final head profile

  4. Edge preparation

    Machining the edge, bevelling and preparing the weld area for fitting to the vessel shell

Pressing a vessel head in the Behineh Ab workshopVideo coming soon

Choosing a head: the balance between pressure, cost and time

For high design pressure or a large diameter, the 2:1 elliptical head usually gives the best balance between plate use and stress distribution, which is why it is the most common choice in ASME vessels. For atmospheric or low-pressure tanks, torispherical or standard dished heads are preferred because forming them costs less. Flat and plate-type heads are only suitable for very low pressure or as removable covers (such as manholes).

To calculate the exact thickness and see the schematic of each head type with your own vessel's real dimensions, you can use Behineh Ab's online calculator.

1Take the design pressure and temperature from the data sheet
2Check the height limit at the installation site
3Compare the cost of plate with the cost of pressing
4Consider die availability and delivery time
Pressed heads in the workshop store

Applications and industries served

Pressure vessels to ASME Sec. VIII
Pressure vessels to ASME Sec. VIII
Atmospheric storage tanks with formed heads
Atmospheric storage tanks with formed heads
Steam boilers and heat exchangers
Steam boilers and heat exchangers
Silos and conical hoppers
Silos and conical hoppers

Buying heads from Behineh Ab

Six steps from first contact to delivery

1Send the head specifications

Give the outside diameter, plate thickness, head type and required material.

2Technical quotation

The calculated weight, unit price and delivery time are sent the same business day.

3Plate supply

Plate is supplied with the mill certificate and inspected on arrival before cutting.

4Cutting and pressing

Cutting the disc, hot or cold pressing depending on thickness, and checking dimensions with a template.

5Edge machining and bevelling

Machining the cylindrical edge and bevelling it ready for welding to the shell.

6Packing and shipping

Packing, issuing the part identification sheet and shipping nationwide.

What sets us apart

Ready dies for the most common diameters
Thickness checked after pressing with a thickness gauge
Profile checked against a reference template for each form
Plate material certificate with every shipment
Hot pressing for thicknesses above 16 mm
Stainless and galvanized heads available

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
Direct line to engineering office
021 - 3345 6789

Your information is confidential and used only to prepare a technical proposal.

Other head types

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