Which type of exchanger head directly bolts to the shell and serves as the pressure-containing head?

The type of exchanger head that directly bolts to the shell and serves as the pressure-containing head is the bell head and tube head. This design is crucial for heat exchangers as it allows for secure attachment and pressure containment. The bell head, commonly used in heat exchangers, employs a rounded shape that promotes uniform distribution of stress and pressure, reducing the risk of failure under operating conditions.

Additionally, the tube head plays a vital role in providing access to the tubes for maintenance, cleaning, or replacement, while also maintaining the integrity of the pressure system. This combination of functionality ensures the exchanger can operate effectively while withstanding the pressures involved.

On the other hand, while other types of heads like flat heads or cone heads have their specific applications, they do not typically serve the dual function of proper pressure containment and direct bolting to the shell in the same way the bell head and tube head do. Each design has its advantages depending on the specific requirements of the heat exchanger system, but for comprehensive pressure containment and ease of access, the bell head and tube head are distinctly suitable.