A steam turbine exhaust end and condenser are prevented from excess pressure by ________.

The steam turbine exhaust end and condenser are prevented from excess pressure by the atmospheric relief valve. This valve is crucial in maintaining the proper operation of a steam system by allowing any excessive pressure to escape to the atmosphere, thereby preventing potential damage to the condenser and exhaust system. The atmospheric relief valve is specifically designed to open at a preset pressure, ensuring that the system does not exceed safe operating limits, which could lead to failures or inefficiencies.

In the context of steam systems, maintaining a proper vacuum is vital as it allows for efficient condensation of steam and effective heat exchange. If the pressure were to rise too high, it could lead to conditions that are hazardous, such as leaks or even explosions. The atmospheric relief valve functions as a safety mechanism by mitigating these risks, which is critical for reliable steam operation.

Other components, such as the condensate return valve, vacuum relief valve, and pressure control valve, play different roles in the overall steam system management, hence their functions do not directly pertain to preventing excess pressure in the manner specified in the question.