What requirement is associated with valves that do not have tamper switches?

The requirement associated with valves that do not have tamper switches is that they require breakaway locks. This is essential for maintaining security and preventing unauthorized manipulation of the valve. Breakaway locks are designed to ensure that even if someone tries to access the valve, it will not easily open, thus helping to protect the integrity of the fire safety system.

Valves equipped with tamper switches alert personnel if the valve is being tampered with, providing a layer of security. However, when a valve lacks this feature, the breakaway lock serves as a preventative measure, ensuring that the valve remains secure until it is necessary to use it in an emergency. This helps maintain proper functionality of the fire protection system, even in the absence of tamper switches.

The other options, such as a digital display or a warning siren, do not directly contribute to the security and operational reliability of valves without tamper switches, while manual operation does not address the specific requirement focused on preventing unauthorized access.