Choice of forming process and temperature
Pressure equipment - Forming processes and technology

Ferrules (shells with a generally circular cross-section) are mainly produced by bending on a rolling machine. In some cases, step bending is performed on a hydraulic press; this technique is used for heavy plates when a rolling machine of sufficient capacity is not available.

Domed bottoms can be formed using a variety of processes:

• stamping with or without blank holder ;

• repoussage ;

• one-off stamping ;

• forming on a forming machine ;

• combined procedure involving several of the above operations.

Each of these processes can be carried out either cold or hot.

Figure 1 defines the application ranges of three forming processes as a function of blank diameter, sheet thickness and forming...