Brief Introduction of CNG Cylinder Production
As a gas storage container, CNG cylinders have been widely used in industry, mining, military, medicine, diving, automobile and other fields. Traditional gas cylinders are made by stamping process to form the upper and lower head parts separately. And weld the two parts. The CNG cylinder production by the spinning process make the CNG cylinder’s gas tightness and pressure resistance performance Significantly improved. In addition, in order to ensure the strength and safety of the gas cylinder, the wall thickness at the mouth and neck has certain thickening requirements. This is difficult to meet with ordinary stamping processing methods. If use the spin forming process, we can achieve a satisfactory wall.
The materials used to manufacture gas cylinders are mainly divided into metal materials, which mainly include steel.
CNG Cylinder Production Process:
Steel CNG cylinders are the oldest type of gas cylinders. Compared with other types of gas cylinders, steel CNG cylinder production have many advantages. Like low cost, safety and durability, and high bulk density. The spin forming technology of CNG cylinder production is a relatively mature process. There are roughly two methods for neck closing and bottom sealing.
Single-Wheel spinning forming
Two methods for CNG cylinder production using this forming process:
1.use seamless steel tubes as blanks, which are closed and sealed by hot spinning.
2.use slabs to deepen by stamping and then spin. We call the pressure-receiving port “E method”.
The basic manufacturing process:
- Seamless steel pipe
- cut into fixed length
- check surface and size
- preheat bottle bottom
- spinning bottom seal
- stamping bottom
- head preheating
- necking
- neck trimming
- drilling, tapping
- heat treatment
- sandblasting.
Closing and bottom sealing are the two key technological processes in the production of gas cylinders. During the production, process requirements to prevent wrinkling and cracking determined the spinning pass and pass thinning rate.
In order to solve many problems, we must control the preheating temperature. We need to reduce the spinning pressure, ensure the spinning quality. If the heating temperature is too low, the stretchability of the metal is poor. This will lead to an increase in the spinning pressure. The inside of the umbilical eye along the back cover will produce shrinkage holes. Defects such as bubbles or inclusions. The forming temperature of steel gas cylinder is generally 900～1000℃
Pressing plate Forming
A friction block or roller with a certain profile compress the end of the tube blank. The main technological process is: steel pipe thinning and spinning→heat sealing bottom→heat closing.
There are various solutions for the spinning of such friction tools due to different tool shapes and movement relationships.
Here is the introduction of CNG spinnging machine:
If you want to get more information of CNG cylinder production, be free to contact us.