Exam Question

### (a) Manner in which Mountings are Attached to the Shell (6 Marks)
Mountings on a main air reservoir, such as safety valves, pressure gauges, and stop valves, are not attached directly to the shell plate. A direct connection would create a significant stress concentration at the opening, potentially leading to catastrophic failure under pressure. To prevent this, a systematic method of reinforcement is employed:
1. **Opening in the Shell**: A carefully cut and prepared opening is made in the reservoir shell at the desired location for the mounting.
2. **Compensating Ring/Pad**: A reinforcing plate, known as a compensating ring or pad, is welded onto the external surface of the shell, surrounding the opening. The cross-sectional area of this ring is designed to compensate for the material removed from the shell, thereby restoring the strength of the pressure vessel in that area.