Head profile · EHA

2:1 elliptical dished heads (EHA), pressed to drawing

A standard 2:1 vessel profile with crown height D/4, pressed in carbon steel, stainless steel and aluminium.

Profile and application

The 2:1 elliptical head, usually specified as EHA, is the common workhorse profile for cylindrical vessels. The ratio D/2h = 2 gives a crown height of D/4. We press the profile to your finished dimensions and confirm the straight flange, openings and edge preparation before quoting.

Outside diameter: Ø203–3000 mm
Wall thickness: 1.5–20 mm
Reference form: GB/T 25198 · ASME VIII Div.1 UG-32(d) form
Typical use: Storage and pressure vessels, air receivers and jacket vessels

For projects referencing an ASME or DIN head form, we press that geometry and hold the dimensional acceptance basis agreed at enquiry. The project's code certification, material approval and third-party inspection route are separate requirements and must be stated before the order is placed.

EHA cross-section. Final height, straight flange and edge form follow the approved drawing.

Specification at a glance

Code	Profile	Reference form	Outside diameter	Wall thickness	Typical use
EHA	2:1 elliptical head (EHA)	GB/T 25198 · ASME VIII Div.1 UG-32(d) form	Ø203–3000 mm	1.5–20 mm	Storage and pressure vessels, air receivers and jacket vessels

The published diameter is the equipment range, not a record that every size has already run. A new diameter or profile starts with a tooling check and, where required, a dimensioned first article for approval. See the full head-type comparison.

Common applications

Pressure vessels

Air receivers, accumulators, separators and general vessel shells.

Process tanks

Reactors, mixing vessels, fermentation tanks and jacketed equipment.

Storage equipment

Cylindrical storage and buffer vessels in carbon or stainless steel.

Materials and finishes

Family	Grades	Typical use
Carbon steel	Q235B, Q345B, SA-36, SA-414G (Q345R on request)	Storage tanks, receivers, general fabrication
Stainless steel	201, 304/2B, 304/BA, 30408 (304L and 316L on request)	Solar and hot-water cylinders, food, pharma, chemical
Aluminium	5083-O and other 5xxx grades	LNG vehicle cylinders, Dewar flasks, cryogenic service
Finishes	2B, BA, pickled, polished — necking zone Ra ≤ 0.4 µm	Where appearance or cleanliness matters

Grades outside the listed families can be reviewed on request. The material certificate supplied with the batch is tied to the heat number.

What to send for a quotation

Finished drawing, size list or sample photograph
Outside diameter, overall height and straight flange
Material grade and required surface finish
Openings, necks, bosses or lifting features with positions
Quantity, inspection requirement and delivery port

If some dimensions are still open, send the application and current sketch. We will list what has to be fixed before a price or tooling decision can be made.

Documentation and inspection

Dimensional report with the agreed measured features
Material certificate tied to the heat number
Radiographic, ultrasonic or magnetic particle testing on request
Third-party inspection welcomed for the agreed scope

Send the RFQ

Questions buyers ask first

What does 2:1 elliptical mean?

The head has an elliptical profile where the major axis is twice the minor axis, so D/2h = 2 and the crown height is D/4. The straight flange and exact edge form are confirmed from your drawing.

Can you press to an ASME or EN head form?

We press standard EHA head forms used by those codes and hold tolerances to the acceptance basis agreed for the project. Certification under a particular code depends on the material, design scheme and third-party inspection route, so tell us the required code at enquiry stage.

What happens if the diameter has not been made before?

The enquiry becomes a tooling check and a dimensioned first article. We confirm whether existing tooling can cover the size, quote any new mould separately and send the first article for approval before the production batch runs.

What documentation is supplied?

A dimensional report and material certificate tied to the heat number are supplied per batch. Radiographic, ultrasonic or magnetic particle inspection can be added where the purchase specification requires it.

Compare other head profiles

Torispherical dished head (THA)

Crown and knuckle radii to your drawing, from thin stainless end caps to heavier low-pressure tank heads.

Hemispherical head (HHA)

Half-sphere profile with crown height D/2 for high-pressure, LNG and cryogenic equipment.

Conical head or transition (CHA)

Conical bottoms and transitions to your apex angle, knuckle radius and straight flange, with or without openings.

Flat head or tank bottom (FHA)

Flat plates with a formed straight flange for welding, including openings and edge preparation to drawing.

Request a quote

Send the EHA drawing or size list and state the required dimensional and inspection basis.

Open the RFQ form [email protected]

Quotes usually go out within one working day. Drawings stay confidential.