The Production Process of Vessel Head

Vessel heads are critical components of pressure vessels, pipelines, and other equipment. Their manufacturing process is rigorous and directly impacts the safety and integrity of the equipment. A head is a component used to seal the ends of a vessel, isolating the internal and external media; it is also known as an end cap. Based on the shape of their outer surface,tankheads can be classified into domed, conical, flat, and composite types.

Dome-shaped heads refer to heads with a convex outer surface, such as hemispherical, elliptical, dish-shaped, and flangeless spherical heads. In terms of welding, they are classified as butt-welded heads and socket-welded heads. They are used in various container equipment, such as storage tanks, heat exchangers, towers, reactors, boilers, and separation equipment. Materials include carbon steel (A3, 20#, Q235, Q345B, 16Mn, etc.), stainless steel (304, 321, 304L, 316, 316L, etc.), alloy steel (15Mo3, 15CrMoV, 35CrMoV, 45CrMo), aluminum, titanium, copper, nickel, and nickel alloys.

In the head production workshop, every product embodies the spirit of craftsmanship and exquisite skill. Today, Jetvsion shares the entire process ofvesselhead production, lifting the veil on the mysteries of professional head manufacturing.

1. Material Selection and Cutting

Starting with raw steel plates, they are precisely cut by a cutting machine and quickly formed into head blanks. Select the steel plate according to the drawings and cut it into a circular disc (blank).

2. Heating

The cut circular steel plate is placed in a large furnace and heated until red-hot.

Carbon steel is typically heated to over 900°C to soften the plate and facilitate shaping; stainless steel or thin plates can sometimes be cold-formed directly without heating.

3. Pressing and Forming

The red-hot steel plate is quickly placed under a massive press, where a die“stamps” it into a dome shape (head).

For small vessel end, such as common styles like oval and butterfly shapes, we use a single step stamping process. This process is not only highly efficient but also ensures consistent quality, aesthetic appeal, and durability in the finished heads. After stamping, a cutting machine is used to meticulously refine the roundness, ensuring every detail is perfect.

For large vessel heads, however, we utilize a spinning machine for processing. The rollers gradually spin the blank into shape, a process that requires expert operational skills and reliable equipment support. Our spinning machine can handle dimensions up to 5 to 6.5 meters, easily accommodating both large scale projects and special custom orders. During the spinning process, the 1.5-meter-by-10-meter semi-finished product undergoes trimming to adjust the diameter, ensuring the final product meets strict standards.

4. Trimming and Heat Treatment

Trimming: The edges of the spun head are uneven, so a machine is used to trim a full circumference to achieve the standard diameter and weld bevel.

Heat Treatment: The head is placed back into the furnace, held at a specific temperature, and then cooled. This process eliminates internal stresses caused by the intense spinning force, preventing future cracking or deformation.

5. Inspection and Shipment

Visual Inspection: Check for cracks or dents.

Dimensional Measurement: Verify that the diameter, height, and thickness meet specifications.

Non-Destructive Testing: Use ultrasonic or radiographic methods to inspect for internal defects.

Results: Upon passing inspection, the head is stamped with a quality mark, a certificate of conformity is issued, and the product is shipped.